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XR7 Dave
07-07-2006, 08:03 PM
Question for those who may have access to flow numbers for our SC heads. How much difference did you get when flowing the end ports vs. the middle port? Also, what do you use for smoothing air entry into the port?

CMac89
07-07-2006, 08:15 PM
I flew my heads after I got them all rebuilt prior to porting. I took them in and flow tested them and got just under 170cfm on the outers and 155 in the center port. This was without an intake on and the altitude was 4200ft. corrected.

As for porting the entry of each port I do it in steps throughout the whole port itself. I use a 60 grit sand roll on an air dremel on the whole length of the port, right before the short turn/bowl area I use a 90 grit and for the beginning of the port I used 120 grit. Using this I pick up an average of 3-5 cfm (slows turbulence at a high RPM) as opposed to a 90 grit finish throughout the whole port. This is for aluminum.

XR7 Dave
07-07-2006, 09:47 PM
So after porting, how close in percent, were you able to get the ports to each other?

CMac89
07-08-2006, 01:46 AM
All of the exhaust ports flowed 128 +/-1 to 4cfm. All I did to the exhaust was clean the casting marks up and make it a nice, smooth transitioned port as i did to the intakes too. I got the intakes to 185 with a 60 grit finish and then did the stepping later so I guess it would be around 188cfm. This was at 3500ft. corrected. On the exhaust I got 142-144cfm.

So that would be about 76%. The ports are decent shaped, but the cross sectional area and the transition are terrible. Not to mention that middle port. I got about 172 on both of them.

During the beginning of spring I found a junkyard SC head and did some experimenting with it. I cut the walls out, filled the floor in and raised it about 3/16", and widened the port. I got 260 with a 1.92 valve that I had sittin around. The port needs to be raised way up to get better numbers. It took about a week to do all of this work and it's one of those jobs that would cost around $6,000 to have done. It's actually a common price to pay.

Randy N Connie
07-09-2006, 11:46 AM
Dave food for thought,
I shaped a peice of aluminum to tac & weld in the S-curve wall
of the center intake port. I only add what I could remove from the
opposite wall. But this will help straighten port out.

Shape a aluminum port plate for floors to raise intakes,two peice.
tac-weld in ,blend. no numbers for this mod to give out :)

Thanks Randy

XR7 Dave
07-09-2006, 12:07 PM
I was wondering what impact the intake manifold has on port flow. Most people tell you to use some sort of areodynamic device at port entry. I understand that they tell you this because when doing cylinder heads you typically don't actually know what manifold is going to be used on the heads. This is typical of the real world and has a lot to do with marketing.

For the SC since we pretty much know exactly what intake manifold is going to be used on the car, why not do your flow testing with the manifold on? Our manifold is, by appearances, a goofy design so it follows logic that it's impact on flow to each cylinder would be relevant to accurate flow testing.

Just wondered if anyone has actually done this kind of testing...

CMac89
07-09-2006, 12:45 PM
I've done a decent amount of heads that an open plenum intake design was used on and there wasn't any change in CFM rating. Only intakes i've seen affected by it was intakes with runners. So I took this into thought knowing it would be a waste of time.

What do you mean by aerodynamic? There's nothing in there that really splits flow. If you mean what I think you do which is put a taper into the entry way of the port that wouldn't help. Only on an intake with an actual runner would it help. You make a taper to the port from the runner on the intake to follow the runner shape on the port. I experimented with it by tapering the port itself and actually lost velocity and CFM stayed the same. However, if there was an intake such as a single/dual plane, tunnel ram or individual runner then it would help alot.

The SC intake is too bad of a design, no matter what you have modified it to you aren't going to get near what a runner type manifold will.

Randy N Connie
07-09-2006, 02:12 PM
There is no reason one could to flow with the manifold bolted a head.
And bolt a plate on the others side of the manifold.

I would like to raise the floor and the top of a manifold. Raising
the floor of are SC bird manifold. I think would be a big plus on
the entry of air to the intake ports.

By raising the top and bottom we can keep the important plenum
volum, since this is a blower motor.

Randy

Mike8675309
07-09-2006, 10:04 PM
When flowing to try and simulate all of that, can you also get the flow bench to bring the pressure up above atmospheric by any amount of boost?

It would be interesting to know. I.e., back cylinders ( or any other cylinder, this is just theory) gain an unproportional flow, but boost causes them to hit their max, but luck has it that their max is met fast, air flows over into the next set, and that's met fast, and the air flows into the last one really fast as well. I.e.,due to the excess pressure all cylinders reach their fill by the time the valves close.

Thus it would be interestig to know.

Randy N Connie
07-10-2006, 08:20 AM
There is no way to get true numbers with flow tests of any type.
Be it on a air flow bench to measure CFMs ,air speed, air direction,
with the use of air,or air with dies,smoke as a marker for measurement.
To use as a judgement tool.

I have read about a flow bench being built buy a shop owner to flow
test A complete long block. Less crank, rods, pistons.With the block
having the bottom of block cut off .From the bottom of the cylinders
to oil pan rail.And make claims that this is the closest one could get
to real world flow numbers.The guy used a degree wheel on the cam
and to turn the valvetrain,& Dial indicator to read valve lift.

Air speed measurement was mentioned. I believe the name for the
tool to read air speed is a manometer.It is basicaly a fan blades with speedometer held or placed in the airs path.You can purchase hand
held meters or mount to flowbench.

It was mentioned about tapers in manifold and runners.If you cut a
SC Bird manifold in half. You can see the manifold tapers down toward
the intake port entrance. I think this not to be to bad of shape for
an open blower manifold ,that fits under the hood. I think we would
have a jump in air flow performance. If we could flip the manifold over
And raise the heads intake ports floors runners.

It would be to much work to mod a stock manifold. But it would be
nice to try and cut out the top and bottom of are manifold out.
Flip the peice over and weld back in. This would help with air flow,
by raising it up to go down into the intake port.Instead of the almost
S curve the stock air path has to travel. And the manifold would still
be tapered toward the intake port to increase air speed with volume.

This post is making me to want to be able to go to the shop and work.
And kick myself for selling my flow bench a few years ago.But it was
small,old,and collecting dust.

Randy

CMac89
07-10-2006, 09:21 AM
Yes I understand that it would be too much work. I was just saying that it isn't near an optimal intake. Ford just made a design that made everything fit and that's the most you can say about it.

There's a small taper in the port, but an effective taper is in an intake runner that, i've seen, atleast has 6"-9" long. The taper increases velocity a big amount.

The reason for raising the port is to get as much as a direct shot, or straight line , of air into the port as possible. The reason why every head i've ever worked on (with exception to casted Pro Stock heads) the ports have be raised significantly.

Always remember this. First comes velocity then flow. If you get alot of flow, but velocity is killed then it hurts motors quite a bit. You have to work with the head to where you can match a good velocity point to CFM then keep going on flow until the velocity numbers start falling. Then you go back to where it was.

XR7 Dave
07-10-2006, 01:10 PM
I was wondering. Since our motors only make power under boost, is it better to flow the intake ports draw through or blow through? I know exhaust ports are flowed blow through because that is how they work - well, aren't our intake ports working the same way under boost? The cylinders do not draw air in, it is pushed in.

Randy N Connie
07-10-2006, 02:48 PM
The closer you can simulate a test to the real world. I would think you
would receive better data to judge with.

With the manifold being open & working as a plenum. I would
think flow test results would be different & better buy pressureizing
the manifold with blow though air.

There are many different types of flow tests that can be performed..

I have heard that some old gear heads ,would use superchargers
when building there flow bench.

Would,nt it be nice if we could just gut the motor of piston crank rods,
remove oil pan. then Bolt the block down on a big home made flow bench table. And drive the blower with an electric motor. If thats what you want,
I think it could be built easy. All the parts are for sale.Just need to be a cabnet builder to hold it together.Or Superflow would build one for ya.

I bet some one like John Force's shop has a bench set up to do this
type flow testing. pressure blow though.They machine there own
blower rotors in house,and use a blower dyno for testing.It would be
nice to see how they do air testing on the blower, intake, heads, block,
as a system.

Randy

XR7 Dave
07-10-2006, 04:50 PM
Setting up a blow through system isn't in the cards for me right now because I don't have time. Sounds like a winter project....

Anyway, I have concluded that the stock intake manifold will cost you about 8-10 cfm on a stock intake port and simply opening the manifold to match doesn't help. You have to put some thought into it and contour the port inlet on the manifold to get back your 10 cfm. I think port entry is critical even on a box intake like ours. This is something that Trick flow did on their new blower manifold. Unfortunately we can't duplicate that kind of port entry but from what I've seen if you don't at least try you will be leaving flow on the table.

So my next question, is what port diameter is necessary to support say, 250cfm if velocity is good?

CMac89
07-10-2006, 07:47 PM
The SC head that I got 260 out of I had a 1.6"x1.31" port. I could have gotten more, but there isn't enough meat to raise the port.

As for blow through testing, yes it is more efficient to find velocity points. We had a new machine that showed in the computer where the air speed was slowing down. Fill that in or take it out where it says and leave it. It works well.

You still can't use it to predict CFM though, only velocity. Draw through CFM is a direct correlation between forced induction and natural aspiration. The difference is in velocity.

Forced induction LOVES square intake port designs.

Mike8675309
07-10-2006, 07:59 PM
Forced induction LOVES square intake port designs.

Is this because the gain from N/A to Forced in a Square intake port is more dramatic than a smooth port? Or does that mean given only a change in port shape, the square port with forced induction has a higher potential thn a smooth port with forced induction?

92strokedbird
07-10-2006, 08:02 PM
Dave I have not seen an example of this Trick Flow manifold.The more important factor is that as you get closer to the proper volume of plenum for the blower that you are using the charge temperature drops.As we increase the output of the blower by overdriving and using different sizes and port configurations the port volume should also change to meet the input change.I would bet that when ford designed the intake plenum they had no idea that we would get these cars to this level of performance.

92strokedbird
07-10-2006, 09:12 PM
Has anyone experimented with the plenum by changing the design and installing runners,I have looked at many designs but have not started anything as other projects are consuming most of my time.The runners would not need to be too long but to get them to equal flows might be a bit of a ~~~~.

XR7 Dave
07-10-2006, 10:07 PM
I was more interested in what can be done with the existing manifold and port design. I'm not going to reinvent the car, not enough time or money. :D

This is the manifold. I didn't find any internal pictures but this manifold was designed specifically for blown applications. It's called the "Box R."

http://www.trickflow.com/media/pr/400/TFS-51500009.jpg

XR7 Dave
07-10-2006, 10:19 PM
The SC head that I got 260 out of I had a 1.6"x1.31" port. I could have gotten more, but there isn't enough meat to raise the port.

As for blow through testing, yes it is more efficient to find velocity points. We had a new machine that showed in the computer where the air speed was slowing down. Fill that in or take it out where it says and leave it. It works well.

You still can't use it to predict CFM though, only velocity. Draw through CFM is a direct correlation between forced induction and natural aspiration. The difference is in velocity.

Forced induction LOVES square intake port designs.

So you are saying that you feel draw through testing is the way to go about optimizing a port for FI or NA, correct?

You say the difference between forced induction and NA is velocity. How is that? I would think that piston speed governs velocity in either case, all things being equal.

Air in the port is either under pressure (FI) or not (NA) but in either case once the valve starts to open it would seem that pressure would be equalized and piston movement would simply create space for the incoming air as it goes down. I guess I'm missing something.

92strokedbird
07-10-2006, 10:42 PM
You could build bellmouths with aluminum tubing or epoxy around the entry into the runners from the plenum.Since most of the flow pushes towards the end of the plenum leaving the back two cylinders without equal air flow.Maybe installing a plate with holes can slow down the air enough to allow the back two cylinders to equalize with the others.It might just work without sacrificing airflow.

CMac89
07-10-2006, 11:43 PM
Forced induction favors square port designs because it has a lot bigger cross sectional area design and that's what forced inducted cars want is big cross sectional areas.

Cross sectional area is something that you can get CFM out of, but is a velocity factor mostly. Cylinders take the air in pulses meaning as soon as that intake valve opens it's taking on air, but until the valve closes (well duh.) This means that the more(CFM) and faster (velocity) air you can get into the cylinder the more power you make. So you have to make the inlet of the port big enough to actually gain the velocity it takes to match the CFM's through the rest of the length of the port. This is what I mean by gaining velocity whether it's NA or forced inducted applications.

Air speed for a high performance forced induction type is higher inside the actual intake port than it is coming out of the forced induction unit in a head that is built/ported right.

seawalkersee
07-11-2006, 07:24 AM
Subscribing to read it later...

Chris

Randy N Connie
07-11-2006, 07:49 AM
On my last manifold that I was using with stock heads.
I had to do weld build-up around a couple manifold ports.
I did this to match the heads smaller ports. I did no flow
tests on the maifold. But seat dyno says there was an
improvment in torque.And the dyno say higher upper RPM
power. But this was with more mods than just the modification
of the manifold ports to head ports.I redone the ports
on my last manifold/plenum,and then sold it to
Steve Webb for $150.00. He runs larger ports than me.

About the only way to build a bellmouth in the manifold,
is if you building a raised top manifold.It was next to
impossible to do weld build up around the intake manifold
ports,and later cut a nice radius around the manifold
port lip inside of the manifold. You need to cut the top
of the manifold off to have accese to do a good job.

I have another manifold that I started on last year. I
hope to finish it before the shootout. I am going to do
a lot of changes from the first 10 manifolds that
I have finished.. I have learned a lot from the first manifolds.
I am really excited about my new design for my last manifold.
I hope to be able to get in the shop this year to finish it.

My plenum will be about the same mods as before,but with a
new shape for the intake IC tube portion. And some changes
inside the manifold.Raised floor and raised top.

Sorry I will not have any numbers to share. I just have a
small home machine shop now,big enough to get some work
finish for myself. I am able to test for a balance flow from
the manifold,But No CFMs.

Thats the extent of my testing.Other than some dyno pulls with
this manifold. The highest dyno sheet numbers was 280.8 rwhp
and 419.2 rwtq. This was with a unsafe level of tune. But I feel
this to be good numbers for a stock motor with modified induction
system. Using an AOD trans with slipper convertor. final tune
was around 274. I have been told the highest stock numbers for
a stock motor with stock modified castings was 288 rwhp,with a
five speed.Did not hear any torque number.

I think and hope that my new manifold will put me up to and over
290 rwhp,and 400 rwtq. While using the MPIII .More when I Add
my A/R blower. looking and hoping for around 325 rwhp with it.

I have a blown head gasket now, to fix before adding a new manifold.
And going to add another cut to my valve job. I bought some new
valve cutters to do my seats & valves. I plan to cut the seat at
15, 31, 46, 50, 60, 70,75, 80. The valves cuts will be 31, 45, 55.

Randy

fturner
07-11-2006, 09:17 AM
Excuse my low mind thinking hear, but here's some of my thoughts....

Take a stock situation, and we've went WOT. Now's there's roughly 13psi of pressure in the intake sitting behind the valves while they are closed, and we know that one valve will be opened allowing air in.

Now to me, its not so much the way the way the air gets to the valve through the intake, but the volume of air that is contained within the intake to keep the pressurized air up especially when running higher RPM's.

Yes, the ports have to be smooth etc to cut down turbulence, and accelerating air into the cylinder is very important so we can get as much as possible in there. But if the "stored" amount of air can't keep up, we'd lose, cause at that point we'd start becoming a non forced application, and I think this is where we hurt the most to start with.

I would say start with a larger manifold that has a larger hold capacity for air, like the box design that Dave showed, then determine the best smoothest way to get that air moved into the cylinder.

Just my little bit worth ;)

Frit

XR7 Dave
07-11-2006, 09:50 AM
What is a good product to use to fill low areas in a port that will adhere to the aluminum and have similar expansion rates so that it doesn't come loose?

CMac89
07-11-2006, 10:06 AM
A B epoxy from Moroso is what I use to fill in ports. A lot easier than welding.

Let us know how it goes, Randy.

xThunderbirdSCx
07-11-2006, 10:15 AM
what are you up to now, dave?

::sniff sniff:: i smell 9's :cool:

XxSlowpokexX
07-11-2006, 11:55 AM
::sniff sniff:: i smell 9's

Better keep sniffing...

The Trick flow box R intake is nothing new in the ford v8 performance arena. Since teh late 80's fabricators have been building box upper intakes for blown (5.0 EFI) applications as well as HIGH RPM Naturally aspirated motors. Trick Flow is just the new kid on the block. The idea behind these intakes was to create a short runner large plenum intake with what was available. What you get is loss of low to mid range torque and HP and a gain up top for deep breathing motors. In a blown car the need for long runners in general are not so important and the boost in fact made up for any loss in that range.

However there is a science and this is where the Trick Flow Intake shines. We are not dealing with all out race cars..We are dealing centrifigally blown engines that make max boost and power in the upper RPM ranges. So trick flow created a big plenum intake with longer almost bellmouth like ending runners feeding into a large plenum upper. This caters more to the street crowd weather they be SC'd or bigger displacement/high revving engines that need that additional air. So less low and mid end loss with great gains up top. Earlier versions were just using stock or gt40 lower intakes with not much thought into the street crowd.

Now with a roots SC due to where we get our boost down low a longer runner intake is not needed and probably wont make a big difference. I'm not even sure how adding plenum area will help or how much woudl be benificial as there is certainly a cutoff point of diminishing gains. Every roots type blower I have used (671 and a 144 ) both used pancake type lower intakes.

After all these blowers almost immediately pressurize the intake. In reality the only way to probably test this type of intake setup is to have it fully hooked up and pressurized via the blower and then take readings. There is the compramise of hood clearence so potentially more plenum space may of been compramised for that additional room. But as far as using a longer runner type intake with the size blowers we use..I dont see it needed. And at the very least not worth the compramise for less hood clearence. Having the air enter the ports smoother (reduction in potential turbulence) however can never be a bad thing

XR7 Dave
07-11-2006, 03:01 PM
I know that box intakes are nothing new, I was refering to the transition into the port, ie. bellmouth that particular intake design incorporates. That's all I was refering to and I'm not suggesting at this time that I am going to spend any time developing a box intake for the SC. I'm only looking at how to improve flow with our existing design.

I was wondering what people use to smooth air entry into the port when doing flow testing. If you attach a true bellmouth to the port you will not get realistic numbers because we can't use a bellmouth. If you don't use anything at all you can get false numbers as well because the intake does significantly affect flow into the port. Even stock heads benefit from proper port matching of the intake manifold just as they can be hurt from incorrect porting.

I only bring this up because I've seen some "port matched" manifolds that, based on what I know now, have actually been hurting flow.

Randy N Connie
07-11-2006, 05:30 PM
I was wondering what people use to smooth air entry into the port when doing flow testing. If you attach a true bellmouth to the port you will not get realistic numbers because we can't use a bellmouth. If you don't use anything at all you can get false numbers as well because the intake does significantly affect flow into the port. Even stock heads benefit from proper port matching of the intake manifold just as they can be hurt from incorrect porting.

I only bring this up because I've seen some "port matched" manifolds that, based on what I know now, have actually been hurting flow.


Some people just use clay, bolt on shaped fixtures if doing the same type head over and over. The main thing is that each port is tested with the
exact same steps when going to the next port..

If you put a bell mouth shape in front of a port ,or clay, it should bring
the numbers up during flow test. by smoothing the air entrance with
a radius shape. It does not matter, as long as you set up each port
test ,the same for each port being tested.

The biggest thing I don't like is, when you get head flow numbers,
people will give the highest flowing port number, and not the average
flow numbers of all the ports. Most heads that are being self ported &
some being sold under a tax number are not being CCed or balanced
for air.

To bad we don't have a raised bolt on top on the manifold. Then you
would be able to bolt the manifold to the heads. And then easily port
match. install a couple dow locator pins in heads or manifold. I may
look in to tring to do that,bolt on manifold top. :)

Randy

XR7 Dave
07-11-2006, 05:39 PM
I've noticed that "stock flow" numbers from a variety of sources don't match. Some are obviously end ports, some appear to be center ports and some just don't make sense.

My goal is to provide even flow distribution from all cylinders with the intake attached. Which leads me to my next question: how close should they be to be considered "balanced?" 5% - 10%? 10cfm - 20cfm?

Another interesting thing I have found is that the center port that is paired towards the rear flows less than the center port paired at the front. :cool:

Randy N Connie
07-11-2006, 05:54 PM
My goal is to provide even flow distribution from all cylinders with the intake attached. Which leads me to my next question: how close should they be to be considered "balanced?" 5% - 10%? 10cfm - 20cfm?
:cool:

Since your a tuner.How close would you want the engine builder
to balance the air in each cylinder. I don't think that with are
cars computor you can tune each cylinder.This would be nice
to be able to do.

You flow test until you get to the perfection level you have set
for yourself. zero difference is balanced,but perfection takes
a long time,if possible. Thats why some head port jobs cost
$500.00 and other can cost $5000.00.

Randy
:)

XxSlowpokexX
07-11-2006, 06:28 PM
Dave,

Basically all flow testing I have ever seen doen used soem type of diffser/bellmouth/ velocity stack. Number will never be realistic unless mounted to teh exact intake being used however without using some sort of transition to teh head you will get very unrealistic numbers that wont even be close to reality. The use of something to smoothout the air is basically just mimicking to a point a potential intake port on an intke manifold.

So in reality the only way to truly test would be with an SC intake and if not under boost how accurate could that even be.

If you stick with the traditional was of flowing heads with some kind of an air transition device I think thast 5the most realitic you will get..

Liek Randy said if you can cut open the intake and work teh runners youd be set.

But then you need to work heads to equal out flow as much as possable....Work intake to not interfere with thosenumbers and keep them equal....Then wonder if all that work was worth it in a boosted car.,,Probably not

No numbers...Just realistic thinking based on what I know (which may be very little)

seawalkersee
07-11-2006, 09:51 PM
How long of a runner are we talking about here for the intake? Since the metal our intakes are made of is cheap, it is hard to weld it properly (thanks Ken), it will be hard to do what I am going to suggest. It would basically resemble a Bullitt intake for a 4.6. The problem is that the intake will have to be compeltely chopped. It would be a skelaton. Just the head face, bolt bosses, front and rear block mating surfaces, the plenum inlet, and the water inlet would remain. You could see through it if you will. Now...sinc I am not sure how much you can effectively ''raise'' the top I will say to make a 3'' tube from each intake port That stretches over to the opposite side of the engine. This will all depend on how much you can fit between the blower and the valley. Then, add depth to the return plenum and get it closer to the valley and make it a plenum so to speak. I think with a bellmouth on the outside of each port, even if you had to angle them down would improve the airflow...like adding an extension to the intake on just a usual port.

Chris

XR7 Dave
07-11-2006, 10:26 PM
Eh, you guys are going way beyond what I'm after. I'm just going to use the stock intake and shoot for a range of 10cfm on all ports and see how that works out. Already I can see that the center ports on the stock setup vary that much between each other based on L and R. The end runners are ridiculous. :eek: To get them within 10 cfm of each other with the intake on is probably way beyond anything anyone else has done.

Of course as Damon has said, what all this means under boost is a totally different story. :cool:

So in looking for incremental improvements, where should I look next? So far we have gasket matched the intake and head, working in no more than 1" from the mouth.

Should I:

- cut in a larger valve?
- start mapping the port?
- raise the roof?
- prep the combustion chamber?
- work the bowl?
- short turn radius?

I will be doing all of the above, but I was wondering what I should do first in order of succession. I want to do things that will improve flow starting from the stock baseline, I dont' want to do things that will not show a benefit until other things have been done as well.

seawalkersee
07-11-2006, 10:42 PM
Well from a purely logical stand point, you should do the mapping first and the cc second. The rest will have to change when you do the larger valves unless you just want to see what stock VS is. In that event,
I would go
Mapping
Chamber
Raise the roof
STR (what are you going to do to that? I would assume that bowl work would be a portion of that.)
Then the larger valves.

That kind of gives you a step up each time. But then you will have to do the bowl work again after the larger valves (provided all of this means new seats and not just larger valves in the stock seats).

Chris

CMac89
07-12-2006, 09:25 AM
Well, It depends on the size valve you want to do. If you have to go to a larger seat then you need to do that first. The throat of the valve seat is supposed to be no larger than 90% the size of the valve.

As for raising the roof that wont do any good unless you fill the floor in also. That's the whole point of raising the roof of the port to get a straighter shot into the combustion chamber. Ever heard of a tunnel ram intake?

I found a 10cfm gain from unshrouding the valves completely, but then you have to mill the heads to get the cc's back.

Trust me, it hardly has it's differenced under boost than it does in an NA motor. It isn't payed attention to with whatever motor all of these NHRA guys are doing. They do it to see velocity changes, but most of the time there aren't any.

I do my Comp Eliminator motor by suck through velocity and CFM testing and I went a tenth faster as opposed to blow through testing and filling the points in. And I know air speed in that motor is higher than it is in an SC motor (450cfm heads.)

Randy N Connie
07-12-2006, 09:28 AM
Eh, you guys are going way beyond what I'm after. I'm just going to use the stock intake and shoot for a range of 10cfm on all ports and see how that works out. Already I can see that the center ports on the stock setup vary that much between each other based on L and R. The end runners are ridiculous. :eek: To get them within 10 cfm of each other with the intake on is probably way beyond anything anyone else has done.

Of course as Damon has said, what all this means under boost is a totally different story. :cool:

So in looking for incremental improvements, where should I look next? So far we have gasket matched the intake and head, working in no more than 1" from the mouth.

Should I:

- cut in a larger valve?
- start mapping the port?
- raise the roof?
- prep the combustion chamber?
- work the bowl?
- short turn radius?

I will be doing all of the above, but I was wondering what I should do first in order of succession. I want to do things that will improve flow starting from the stock baseline, I dont' want to do things that will not show a benefit until other things have been done as well.


To start a port job.
1. Make sure the aluminum in the bowl area stands equal to or above the seat.If aluminum is below the seat.Pull seat out and do weld build up. this
is also the time to do any and all weld built up. You just need to inspect
the areas that need to be built up with weld.below seat bowl area,ports
floors,port walls,port roof.

2. Cut seat and bowl area to have a match transition. Tool that I use Mounts
in a bridgeport mill. Tool has a 8 collect to fit in mill.Then has an universal
joint in the center of tool. The tool has cutters that are radiused on the end,
so when cutting the seat & bowl.The radius shape on end of tool cuts
a smooth transition from seat to bowl. the radius cutter will leave no sharp end in the bowl.So later you can easly blend the bowl area. After this cut
you should have a perfect transition between seat and bowl area.To purchase tool go to. www.goodson.com

3. use machinest die to coat the intake & exhaust port entrance & exit.
Then scribe the port face surfaces with gasket, to gasket match the ports..

4. now you have both ends of your port cut to your spec's.So you now match the center of the port to match the ends of your port.In your style of porting.
Of course there is more to this step.Like welding the exhaust or intake floors,
etc before you start this step and reinstall the seat..

5.After port work is close to finish.You can chuck up your valve guides in a lathe and cut diameters or length you want the guides to be.Depends on the head & the heads use,All out racing head you can totaly remove the portion of the guide that protrudes into the port. for street performance you can cut to shorten the guide and cut a taper on the guide.This guide mods helps in flow.If you doing this type mod on the guides,I also install thin-stem valves.

6. after you finish your porting,And CCing and balanceing the ports & combustion chamber.Before CCing,In the combusion chamber, if you want to do valve unshrouding.. The only accurate way is the use of a tool made for this job. The tool has a round cutters This tool will cut the proper profile
needed to promote swirl in the bathtub shaped combustion camber.
The tool needed to do this type cut, fit's the same tool that I make the
seat to bowl area cut. Goodson mfg.

You can now finish the valve job. The best tool I have seen for a small shop.
That you can cut 5 angles with, AND they are very accurrent & priced right.
www.newaymfg.com 3 angles cost around $800.00 5 angle cost around $1200.00

As far as porting by mapping. When you come up with what you think is your perfect port.You can buy a two part rubber to fill the port. Let set up for a few minutes. Then remove the rubber casting from you port.Next measure
evey .250 inches.Then draw a circle around the rubber mold every .250''
the length of the casting. Now you can measure the diameter of the mold with a outside caliper.Transfur your measurement from the outside caliper
to a inside caliper.Then you can start to measure with the outside caliper
inside of the port your working on.

You use the outside caliper to measure, left to right & top to bottom of
the port.You make this muti measurement every .250'' the length & diameter of the port to match the molds length diameter in the port. I last bought two part rubber for port matching from MANLEY valve company.

Dave, This is a short list,I can fill in any blanks if you ask. And there are no stupped question to me, so ask, some points I may go off line with though.
I have hardly even scratch the surface of modifications done to heads.

And I don't know every thing there is to know.I just know what was self talt
to myself and hand me down info from old gear heads.,my first head port job was done with a drill and a tapered stone and sand paper wraped around my finger in 1968. So by no means am I a sheep skinned carriering eng. that knows it all.

I am out of coffee, and I think a hooker is at my front door,got to go.
Later Randy

XR7 Dave
07-12-2006, 09:54 AM
Ok, keeping in mind that this is not a one-off museum quality job that I am starting on, I think we agree here that after gasket matching the intake the next job of the day is to select a valve size and fit it to the seat.

To keep costs down and enhance reliability I'm going to be using stock seats. I've measured a bunch of SC valve seats on different heads and I've come to realize that they don't all measure exactly the same. I've measured some as small as 1.840 and some as big as 1.870. I am going to be keeping this in mind because I never know what I'm going to run into until I get started. With that in mind I plan to use a 1.850 valve. According to what Casey has said, with a 1.850 valve the throat diameter (with a .030" seat) maximum is 1.656. Stock is 1.635 so I'll start by opening the throat to the max diameter and cutting a 3 angle seat for the 1.840 valve using a pre-formed cutter such as Randy mentioned.

It doesn't really make any sense to put in the bigger valve without unshrouding so I'll make that part of step 2 also. I'm going to use a pre-formed cutter for the initial test and then I'll experiment with some additional work to see if it helps any. The pre-formed cutter will be sized to cut to the outside boundary traced by scribing the headgasket onto the head. Is there any "rule" about how much the gasket needs to be covered so as to not expose the fire ring to excessive heat?

Randy N Connie
07-12-2006, 10:38 AM
1.I always start with all prep work, cleaning, weld build ups.

Then scribe gasket match marks for the intake manifold to intake ports in heads. I cut or port so the manifold port is .010 to.005 smaller than the
heads intake port.

Then next make the cut to match the valve seat to the heads port bowl area.
With a SERDI tool or the goodson tool. The cutters in the tools should have a raiused end. This is so the cuutter will not cut a deep s line in the bowl area.

The SERDI or GOODSON cutter tool can also be used to inlarge the seats diameter .And make all seats diameter matched.

Don't do the other valve seat cuts until your finshed porting. Only make the
90 degree cut on the seat,reaching down into the bowl area surface
around .050 to .075 on an inch.Just enough to match the surface of the seat and bowl area.

The cut on the seat to bowl area is very important.It makes the seat and bowl area concentric to the valve guide. Lop sided seats and bowl areas do not flow well.

Now you have a concentic bowl to seat to valve guide.And if you have
scribed gasket matching marks from intake manifold to heads intake port.
And scribed the header exhaust flange ,and cut the seat to bowl area.
You now have centered ports that are concentic to the valve guides.
this is very important steps. These steps are the main ones that cut the
pro port job from the home port job. You must match diameters (seats)
and get every thing centered first.

Now you should have the gasket match finish around .100+ into the
intake and exhaust flange head ports..And you now have the valve seat to
bowl are matched. Now you add your style of port shape between
the gaskets flanges to bowl areas by blending the center portion of the ports to your pre-machined and gasket matched ends.

2.The second valve cut to make.I use a 15 degree tool with a radius end cutter. This is the first cut to make on the combustion chamber side.
This cut blends the top of the seat to the combustion chamber surface.
The cutter will cut the top of the seat and the combustion chamber at
the same time. The raduis end cutter will give a perfectly smooth transition
between the seat to combution chamber. After this cut you are done doing any type valve seat cuts until the porting is completly finished.

You now should have a perfectly blended valve seat to bowl that is concentric to the guide, And the intake entrance and exhaust centered
to the manifold and ehaust headers.

Recap for first two valve cut to be made.
So after prep work and any weld build up is finished. I make one valve cut
at around 90 degrees with radius cutter to blend valve seat to bowl area.
The second valve cut should be the 15 degree cut made to the seat and combustion chamber. Then you are done cutting the seats until porting is finish.



Randy

Randy N Connie
07-12-2006, 07:35 PM
WHOOPPSS hit the delete key :confused:

Randy

XR7 Dave
07-12-2006, 09:50 PM
Well, I'll be going to the machine shop tomorrow to cut out the seat as per Randy's instructions keeping in mind maximum throat diameter.

I used some of my own tools to do the chamber cuts and unshrouding within the chamber and the results are really good so far. So far I've gained 20% in the .200-.300 lift area and we have done no porting within the port at all yet and it still has a totally stock valve in it. Once you get to .500 lift the gain has evaporated though, either that or there are other things holding us back at this point.

CMac89
07-13-2006, 09:52 AM
Once you get to .500 lift the gain has evaporated though, either that or there are other things holding us back at this point.
With what sized valve? The reason for asking because too small of a valve causes that. The position of the port is part of the cause too, which is why I raised it.

Randy N Connie
07-13-2006, 09:56 AM
whoops hit the delete key :)
later Randy

XR7 Dave
07-13-2006, 10:11 AM
Stock valve. Haven't actually done any porting yet. I was surprised how much improvement just unshrouding made.

ScrapSC
07-13-2006, 02:57 PM
Thinking of having a set done. Have any good pics of what a set looks like when finished up????

XR7 Dave
07-13-2006, 06:34 PM
Sorry, no digital camera. :/

ScrapSC
07-13-2006, 11:47 PM
See that is what happens when ya spend all that money on the car. Thought you would be up on this digital age shiznit... LOL I got mine apart and hate the idea of not unshrouding the valves before putting the heads back on. Guess I need to give the machine shop a call and see what he can do for me.

XR7 Dave
07-14-2006, 12:00 AM
Well today we cut in the larger valve. In the process we went with a basic 3 angle seat and enlarged the throat slightly paying close attention to margins. Seat is .035" with a .080" 60 deg lead and then straight into the bowl about .100". According to what I've read and heard that is basic performance stuff. Because of the small valve and smaller seat there just isn't much real estate to start getting fancy so we called it there.

Initial tests showed that low flow below .100 was decreased. Not sure why that happened, any ideas anyone? Improvements didn't show up until .300" lift and from there things got nice very quickly with a 15 cfm increase at .400". I've been noticing that flow has definitely flatlined after .500" in all testing though so I tried taking off the intake manifold and voila! 10cfm at high lift. Makes me want to ask, how would those other "trick" cylinder heads flow if they had an intake manifold on them??? Hmmmm.

Without getting into any runner work at all we are looking at a 30% gain so far in the .300-400" range. I'm starting to think that the dogleg in this port is neutering flow at about 190cfm. Oh ya, I forgot to mention I've been doing all my testing on the center port. I figure once I find the limit on that port, getting the others to match should be easy. :D

XR7 Dave
07-14-2006, 12:01 AM
See that is what happens when ya spend all that money on the car. Thought you would be up on this digital age shiznit... LOL I got mine apart and hate the idea of not unshrouding the valves before putting the heads back on. Guess I need to give the machine shop a call and see what he can do for me.

Spent the money on tools, actually. ;)

Nettlesd
07-14-2006, 09:27 AM
Sparky,

I take it this is something that you will be offering in the future?

Randy N Connie
07-14-2006, 09:49 AM
Well today we cut in the larger valve. In the process we went with a basic 3 angle seat and enlarged the throat slightly paying close attention to margins. Seat is .035" with a .080" 60 deg lead and then straight into the bowl about .100". According to what I've read and heard that is basic performance stuff. Because of the small valve and smaller seat there just isn't much real estate to start getting fancy so we called it there.

Initial tests showed that low flow below .100 was decreased. Not sure why that happened, any ideas anyone? Improvements didn't show up until .300" lift and from there things got nice very quickly with a 15 cfm increase at .400". I've been noticing that flow has definitely flatlined after .500" in all testing though so I tried taking off the intake manifold and voila! 10cfm at high lift. Makes me want to ask, how would those other "trick" cylinder heads flow if they had an intake manifold on them??? Hmmmm.

Without getting into any runner work at all we are looking at a 30% gain so far in the .300-400" range. I'm starting to think that the dogleg in this port is neutering flow at about 190cfm. Oh ya, I forgot to mention I've been doing all my testing on the center port. I figure once I find the limit on that port, getting the others to match should be easy. :D

seat and valve Margin widths has a lot to do with flow. To wide, the flow falls off. to narrow on exhaust seat cut burns .050 or narrower would be for racing only. If you have a 46 degree cut for the valve seat with a.035 width.I would think this to be a min width to cut, on the exhaust side.

This is what I do, have a cut before the 46 degree valves seatcut of around 31 degrees.With radius end cutter. The radius on the end of cutters,keep the cutter from cutting a grove into the combustion chambers aluminum.

Next cut with RADIUS end cutter should be 15 degrees. This 15 degree cut starts at the seats 31 degree cut and extends on to the combustion chamber
surface. This last 15 degree cut blends the seat transition to the combustion chamber .You should have no groves left around the area that the seat meets the combustion chambers aluminum. This 15 degree cut will bring the low lift back up.

The 15 , 31, degree cuts should be around .010 to.020 width max . I like
the 46 degree valves valve seat width to be .040 TO.050 min on the exhaust side. Intake valve seat cut can be cut down to your .035 to .040 min valve seat width.This is for racing heads.

All the seat cut widths are very important for low lift flow numbers. And
high lift. I believe the biggest gains in air flow will come from seat cuts.
By making a perfect smooth tranision between seat to bowl area with a 60,75,90 degree cuts. And the 15 & 31 degree seat to combustion chambers Aluminum surface. the transision should be as smooth as glass.And the 46 degree valve valveseat cut width should be narrow but not so narrow on the exhaust side that the narrow valve valveseat margins cut surface burns .

There is plenty room for a five angle seat cut, I am going to try to go with seven seat cuts. Plus two cuts before and after the 45 on the back of the valve. This adds up to a 10 angle valve and seat cut. . I have never done
this many cuts before on a SC head. I now have 7 angle cut on my heads & valves, 5 seat cuts and 2 valve cuts. Seat cuts are 15radius, 31radius, 46, 60, 90radius cuts. Standard valve cut of 45 degrees.

Got to go, out of coffee .:)

Randy N Connie
07-14-2006, 09:56 AM
Thinking of having a set done. Have any good pics of what a set looks like when finished up????

I have some ported heads and welded ported heads to take pictures of.
But I am waiting to barrow Daves camera. :/ :)

Randy

CMac89
07-14-2006, 10:14 AM
I hardly even look at flow around .100-.200" because the valve, regardless of the size, becomes an obstacle for flow. A low degree first or secondary cut can help, but that's not where power comes from. I got 17cfm on my superstock heads by going from 45* to 57* (the limit is 58*) and the horsepower definitely didn't come from low lift flow. The reason for this is to get the air off of the cylinder walls and keep in shooting down narrowly into the cylinder.

I honestly didn't see any differences with 7 angle and a 5 angle.

Randy N Connie
07-14-2006, 10:28 AM
I hardly even look at flow around .100-.200" because the valve, regardless of the size, becomes an obstacle for flow. A low degree first or secondary cut can help, but that's not where power comes from. I got 17cfm on my superstock heads by going from 45* to 57* (the limit is 58*) and the horsepower definitely didn't come from low lift flow. The reason for this is to get the air off of the cylinder walls and keep in shooting down narrowly into the cylinder.

I honestly didn't see any differences with 7 angle and a 5 angle.

When you went from 5 angles to the seven angles,did you do any valve back cuts? Back cutting angles on the valves can help some with low and high lift flow numbers.

I would also think Dave would want to add a cut between the 46 and 60 degree cut. But I am sure that he is not listing every degree cut.And maybe
his machinest is limited on cutters tool cut more angles.A lot of automotive machine shops still think a 3 angle valve cut is just fine.It is just fine for street to strip.But three angles is not enough for all out national classed performance.

When the basic seat area are finished.Additional work will start to show smaller gains in air flow,with no weld build ups in the ports.. But the 2 to 5 CFMs hear and there add up to a fender at the finish line at the drag strip.
Of course 7 angles are worth doing.

Some name a 7 angle valve job with 5 angles on the seat and 2 angles on the back cut valve.

My name for seven angle valve job is 7 angles on the seat. The two
to three cuts on the back of the valve. I call this back cut angles on the valve.
Some would call this a 10 angle valve job.


Thanks Randy

CMac89
07-14-2006, 11:28 AM
I call it 5 angles for 3 on the seat and 2 on the valve. Yeah the 2-5 CFM's add up, but the question is where at in the whole lift sequence (rhetorical)? My point was that flow needs to be mainly gained at mid to max lift because there will be alot of turbulence to overcome at low lift.

If you can find a good angle to get rid of a decent amount of turbulence on low lift then it would be beneficial on a forced inducted motor. Just remember that the valves are canted and the face of the valves aren't exactly parallel with the pistons. Air is drawn straight down on an 11* canted valve.

XR7 Dave
07-14-2006, 12:29 PM
I hardly even look at flow around .100-.200" because the valve, regardless of the size, becomes an obstacle for flow. A low degree first or secondary cut can help, but that's not where power comes from. I got 17cfm on my superstock heads by going from 45* to 57* (the limit is 58*) and the horsepower definitely didn't come from low lift flow. The reason for this is to get the air off of the cylinder walls and keep in shooting down narrowly into the cylinder.

I honestly didn't see any differences with 7 angle and a 5 angle.

My seat angles follow almost exactly the recipe given by Bill Jenkins way back in the 70's. I realize things have come a ways since then but I figure these heads should respond appropriately to tried and true methods.

Jenkins called for a 30 deg lead from the chamber and he said if the seat is real high you can go after an additional 15 deg cut. In the case of the heads that I'm doing now the seats seem to be sunk in deeper than on some others so the valve is sitting a little low IMO. I don't see enough room to do a 15 deg top angle, especially on the wall and eyebrow side.

Then he said the seat should be .080" followed by a sharp 60 deg cut .100" wide and then 90 deg straight into the bowl, no radii on any cuts. In our case we have the seat cut to .035" and an .080" 60 deg followed by a 90 into the bowl with .100 drop before any radius. This is as close to the Jenkins recipe we could come and it also has at least some to do with what cutters we have available. I'm not opposed to buying new cutters, but would anything else really help? If I were to put a 75 deg transition between the 60 and 90 how wide should I make it? Keeping in mind that the real estate has to come from somewhere, I'd have to either narrow the 60 deg face or close up the throat some to make room for the 75.

I was just going off the statement that Jenkins didn't use any additional cuts on his Pro Stock small blocks. He also mentioned a back cut on the valves but he said you should maintain at least .080" face on the valve. Was that simply because they were running .080" wide seats or is there some other reason? We back cut the valve to within about .010" of the lap line which ended up being a pretty big cut on the valve. Was this a mistake? I'm going to try a minimal back cut on a valve and see if it make any difference.

That and I'm also going to start porting now. :D

XR7 Dave
07-14-2006, 10:35 PM
So I'm finding out that the intake manifold seems to be limiting airflow - in a large way. :mad:

seawalkersee
07-14-2006, 11:54 PM
Well...first thing to do is cut that funkin triangle out of there and see what you get. Then would be to have the opened up plenum flange....

Chris

XR7 Dave
07-15-2006, 12:25 AM
Triangle's got nothing to do with it. I'm losing 15cfm at .600" lift with the manifold on vs. nothing. Up to .500" the two are neck and neck but from there on the flow actually DROPS with the manifold in place. In other words the port flows more air at .500" than it does at .600".

I feel it has almost completely to do with the approach angle. I think the approach is causing turbulence in the port. Some how when the port starts to draw more than a certain amount of air the manifold just chokes.

What a joke! We have been chasing all these fancy cylinder heads and we have an intake that is simply choking them. I will be testing the head with Randy's manifold attached tomorrow. I'm really hoping for some good results because this is depressing.

CMac89
07-15-2006, 12:35 AM
This intake is horrible and i've always known it. I don't know what else anybody would think. That intake has turbulence spots every inch of it. TERRRRRIble.

Case and point, you have to build a head with the intake on to get a real life scenario and performance. And like I said before, modifying the stock one isn't the answer, though it can make it a bit better. For best performance a runner style intake would have to be used.

seawalkersee
07-15-2006, 09:19 AM
What a joke! We have been chasing all these fancy cylinder heads and we have an intake that is simply choking them. I will be testing the head with Randy's manifold attached tomorrow. I'm really hoping for some good results because this is depressing.

That was going to be my suggestion...

Chris

Mike8675309
07-15-2006, 09:55 AM
What manifold pressure are these tests run at? My feeling is there will be some influence on air flow when pressure is higher than when it is lower. Can't find an online reference for that, or at least can figure out how to search for it.

The question in my mind is that if at 10psi, 20psi, is the same limit point in effect, or does it move due to changes in the dynamics of air flow at higher pressure?

That doesn't mean the manifold is lovely, but it may change where the flow throttle is.

With that said, any runner style manifold is going to require a different hood, or different k-member to drop the engine lower. What are the chances of building a sheet metal intake manifold?

For grins, you might want to try and track down a couple 3.8 intake manifolds currently available and just try them on the SC heads. See if any of the currently available heads (of course, none have support for mounting the M90) flow better. Thus giving a hint at a beneficial design.

Randy N Connie
07-15-2006, 11:06 AM
I have not tried it yet, but I have been planning to raise the
floor of the manifold up for a couple + years.. I think this would
be of great help on the air entering the intake ports.Raiseing
the roof and the floor was Mike 38 and my last manifold
modification to do. We both ran into personal problems
and never got around to finish this project.It should
be finish, I hope, by the shootout.

By raising the top and the floor of the manifold with
plenum mods. I believe the heads intake ports could
be raised at the opening by .250 maybe more, with some
welding. And still appear fairly stock.

But then the top of the manifold would need to be raised
around 2.5 plus inches.Not a problem for me since I have
a Cobra R hood and a K-Member.

It would be very easy to build a better flowing manifold
from sheet aluminum.That a M90 , 2.3, or an A/R blowers
would bolt onto.

But since I like running in stock modified type racing
And I like opening my hood,and telling people its all
stock parts. I just have not built a manifold from scratch.
If I do a SC BIRD 3.8 motor build up for record setting times.
You can count on it, that I would be running a scratch
built manifold.And this is just around the corner..

But I think most SCers are like me.They want to stay with
a mostly stock designed castings for a stock looking motor.
Its a lot easier to build scratch built racing parts,Its not
always easy to improve stock designed castings .

By combinding others design manifold/plenums together.
And building my manifold with the larger plenum,
larger plenum opening,diffuser, and raising the roof.This greatly
increase the plenum effect. This manifold was designed to
have more air waiting to flow for higher RPM use. and it
works great for this. But I beleive raising the floor would
cut turbulence down while entering the heads intake ports.
To build some extra RWHP,instead of only widening the
RPM power band

Everyone may not like the stock SC/XR7 manifold design.
But Coy M., Jim D. have ran a raised manifold.Chris W.
ran a manifold with larger plenum, & larger plenum opening.
David N. runs a diffuser in his plenum.David Dalke makes
good top end power to. And where are they all at on the
fastest SCCoA list. I am not on any list but I would guess
that my stock motor is in the top 3 ever to make the rwhp
I can.And I use a larger plenum/plenum manifold opening.

Since I am writing about bolt-on parts to the heads to
improve flow.I think a set of headers that have been raised
and stepped would also help out with power.

Later Randy

XR7 Dave
07-15-2006, 12:58 PM
Found out some enlightening things today.

First, I think that plenum volume is a secondary problem. I think that the biggest problem is the fact that the port, by virtue of the intake manifold design, does not and can not end like a flat bell shape. It is forced to end up at an angle with the roof badly shrouded.

I have a question for those who have actually flowed heads. Do you flow test with an injector installed or do you leave the hole open? I found this makes a huge difference and it is easy to be concentrating so hard on the port shape that you forget about that additional air source. ;)

Anyway, back to the meat and potatoes here.

My stock head flowed 147cfm @ .500" lift with the stock manifold on and injector installed. This is the center port with the big dogleg.

After porting and larger valve (not a finished port, just roughed in) I got 193cfm @ .500" lift - with my ported intake on it. With the stock intake the same port flows only 175cfm. And here is the kicker...with a basic port match only (I have a nice looking one here done by an un-named person) I saw no increase at all. I was surprised, but simply opening up the port to match the head doesn't result in a flow increase. :eek:

What I did was apply a very wide and very smooth radius to all areas around the port except the top of course and that part I made sure that the angle of approach matches the head. This made a very big difference and up to .500" lift the port actually flows significantly better with the manifold than without. After .500" lift all bets are off though. :(

So after all that it appears to me that manifold porting and design is of at least as much significance as port design in this case. It also tells me why guys like myself and Kevin have run so well with .500-.540" lift. Anything above that seems to be wasted. :cool:

Now on to Randy's manifold.... :D I have only begun testing so don't take this as the last word, but so far the flow #'s most definitely did increase. I got 199cfm @ .500" lift and a peak of 200cfm @ .530" lift. After that even this manifold is falling out of favor. Does it do what Randy said it would do? Absolutely. This manifold allows you to run more lift effectively and it does flow more air into the cylinders. Makes me mad now that I didn't have more camshaft when I was testing it. I only had .513" lift. :(

XR7 Dave
07-15-2006, 01:02 PM
Mike,

Taken from what Casey said about flow under boost and adding logic or common sense, it follows that flow under boost won't be much different than NA flow. The fact is, as soon as the valve starts to open the slightest amount of pressure difference between the manifold and port are equalized and the piston motion is what determines how fast air must flow into the cylinder. The fact that the air is a little more dense should have minimal effect on it's flow charactoristics.

This has been a difficult concept for people to wrap their minds around. We all keep thinking that the air is being forced into the cylinders under pressure. Mechanics suggests that this is not true. Pressure is simply equalized between the chamber and the intake and then the piston draws the fluid in. So I think that the volume is the same and only the density changes which, as I understand it, makes minimal difference to the flow characteristics of the air.

seawalkersee
07-15-2006, 02:59 PM
Yes...as boost is just realtive to resistance/restriction. I would plug the hole for the injector...How would you flow a 5.0 head with no port? It has to be relative to the actual unit on the car and there would be NO air coming from the port at that point.

Did I read that correctly that the intake increased the flow of the heads?

Chris

XR7 Dave
07-15-2006, 04:33 PM
I would plug the hole for the injector...How would you flow a 5.0 head with no port? It has to be relative to the actual unit on the car and there would be NO air coming from the port at that point.

Chris

My point is that most heads do not have a hole for an injector. Most heads have the injector in the manifold. I just wondered what people do because when looking at the charts that get posted around here for stock heads the only way I can get close to those numbers is to leave the injector out. I wasn't actually wondering if it should be in there, I'm wondering how people get such high flow numbers for stock heads. Coy claims over 180cfm on a stock head. I'm not even getting 150cfm, and it took a LOT of work to pass 180cfm.

XxSlowpokexX
07-15-2006, 04:33 PM
This manifold was built to work under boost. This type / style of intake has been around for years under boosted applications. I think you are wasting you time worrying about flow numbers n/a with manifold on/off. The game will completely change uder boosted conditions. And the intake is only one variable playing into effect of the flow numbers. I'd just work on getting the Heads to flow within a good % of each port and make the transitions in the intake smooth.

XxSlowpokexX
07-15-2006, 04:36 PM
Dave,

Coy uses a diffuser as do most engine porters who flow heads. Leaving a raw open port is a bad simulation. Also the inches " of water when flowing will effect the outcome. I dont know of a reputable flow testes that doesnt use some type of a diffuser to simulate a port

boostedbird
07-15-2006, 10:53 PM
Well after reading Daves comments about the stock manny and everything I decided to go ahead and take mine off and put my foredom to work and port the manny really it made sense I had these VERY nice ported heads with bigger valves and all and a big cam and a big inlet 85mm TB 3.5 in intake and all but still had this bottle neck with the unported manny. So off it came I used the old gasket as a reference and did as Dave said didn't raise the roof too much brought the floor down opened it all evenly up to match the heads and put some very good wide radiuses on each port making sure not to overdo it but to help get air into the heads better. After all was said and done I reset the computer let it learn then took it for a test run, hard, and what I saw was boost rose alot faster and increased by 1 PSI and I have alot more top end wants to pull past 6600RPM where it normally is wanting to shift but its feels like it would keep going hard! Good mod for $18 and a little time! Thanks for the info Dave as always helping us out and keeping us informed! :D

David Neibert
07-15-2006, 11:36 PM
Everyone may not like the stock SC/XR7 manifold design.
But Coy M., Jim D. have ran a raised manifold.Chris W.
ran a manifold with larger plenum, & larger plenum opening.
David N. runs a diffuser in his plenum.David Dalke makes
good top end power to. And where are they all at on the
fastest SCCoA list. I am not on any list but I would guess
that my stock motor is in the top 3 ever to make the rwhp
I can.And I use a larger plenum/plenum manifold opening.



Randy,

In addition to the oversized plenum opening and the diffused plenum, I've also got a considerable amount of work done on the intake ports. They are all about 1/8" taller and about 1/16" wider than a normal ported head.

This required welding extensions to the top and bottom of all the ports on the intake manifold and also requires handmade gaskets. I've always considered them a wasted effort because the car didn't make any more power than the regular Steig heads. Then again it seems to be making good power now, so who knows.

David

boostedbird
07-15-2006, 11:47 PM
Randy,

In addition to the oversized plenum opening and the diffused plenum, I've also got a considerable amount of work done on the intake ports. They are all about 1/8" taller and about 1/16" wider than a normal ported head.

This required welding extensions to the top and bottom of all the ports on the intake manifold and also requires handmade gaskets. I've always considered them a wasted effort because the car didn't make any more power than the regular Steig heads. Then again it seems to be making good power now, so who knows.

David

Dave I also have the same type of porting done to my heads and now the intake too it was hard to get to that big with the foredom but I got it done and I just had a ? for ya I know you probably noticed that the felpro intake gaskets do not fit but have you tried the victor reinz intake gaskets? I too was having gasket fitment probs but the victor fit almost like it was made for ported heads and intake!!!:D

fturner
07-16-2006, 09:50 AM
First off, when you guys are flow testing are you using water?

Cause if you are, then all the CFM you will ever measure in my opinion is for a non boosted application. One BIG thing that is missing is the fact that water or ANY fluid for that matter does NOT compress, BUT air does. Once you have pressurized the intake manilfold that changes everything on how everything flows. If you need to simulate flow with water, then you'd need to put pressure on the water by pumping air into whatever your using to flow water into the heads, for instance 15psi of air behind the water. Like what you do with a water tank.... you need to pressurize that tank with air.

As for what the pressure does for air going into the cylinder, I would think the pressure will accelerate the air into the cylinder because you are going from a pressurized area to a vacuum area, causing the air to accelerate into the cylinder to equalize that pressure, and the bigger the pressure difference the faster the air moves into the cylinder, hence having an air supply big enough to keep up.

There's 2 main ways to get air into the motor, one way is high pressure low volume (like the old turbojet days) or low pressure high volume (like the modern turbojet engines). In cars we have to balance between these cause we only have so much room to open things up, but ultimately we would like the low pressure high volume because its alot more efficient with the main reason is lower pressure lower temperatures as we all know.

I'm referencing to jet engines because there is similarities to a standard gasoline engine. They both suck-bang-blow and they both become more efficient and more powerful the more good air charge we can get into them.

Anyways, just another blurb.

Frit

Randy N Connie
07-16-2006, 10:39 AM
I have a question for those who have actually flowed heads. Do you flow test with an injector installed or do you leave the hole open? I found this makes a huge difference and it is easy to be concentrating so hard on the port shape that you forget about that additional air source. ;)
:(

I have only flow tested one 3.8 SC bird set of heads for CFMs.
While testing for port mod results.I used the injector while testing.
Just leave the O-ring on and push the injector in.

Leaving the injector out would not be good for true flow numbers.
because of Air leak. I would suppose a person could use ay type correct
diameter plug to put in the injector hole.

The injector does not protrude into the ports, Or air flow path. So I
would not think the end of the injector would hurt or increase any
flow numbers with injector installed.

And I used Play-Doe clay for a diffuser, for CFM tests.

I am not so concerned With CFMs as I am with linear air.
So I use and see a wet flow tests to be the best tool to start
testing with. Once the air is flowing as linear as possible. Then
I will test for CFMs.

If you know your final horse power goal. And you have linear air flow.
Then you start with testing to increasing the CFMS. How do you do this,
I try to keep my linear flow port shape. Then I increase the CC volume
of the port to increase CFMs.

If I know my final horse power goal. And the way I can do this is
with a engine profile computor program. It takes certain amount
of CFMs of air to make a given amount of horse power. You add the
stoke ,bore,cylinder number,cam lift etc. to come up with needed
air CFMS to produce the horse power goals.

Thanks Randy

Randy N Connie
07-16-2006, 11:23 AM
Randy,

In addition to the oversized plenum opening and the diffused plenum, I've also got a considerable amount of work done on the intake ports. They are all about 1/8" taller and about 1/16" wider than a normal ported head.

This required welding extensions to the top and bottom of all the ports on the intake manifold and also requires handmade gaskets. I've always considered them a wasted effort because the car didn't make any more power than the regular Steig heads. Then again it seems to be making good power now, so who knows.

David

I remember you saying that you had welded intake ports.
That is a very wise step you made.

Now you just need to complete your head mod.You needto
get a pro built raised manifold to match. With the half S
curve at the manifold exit modified for liear air flow.

If I was building a Raised manifold/plenum for you. I would dowlpin
the manifold and heads to have permanent port locator.
Then port match your manifold, manifold gasket, to heads
While bolted together. Before welding the manifold top in place.

Its my guest-sta-ment that you would extend your RPM power
band by 500 plus RPMs. And gain around 20 rwhp.With the raised
manifold with the manifolds half S curve exit modified for
linear air flow. This mod will also open the door for more cam
if you so choose.

Are you still using that MP IC tube plenum adapter,restricter plate?

Thanks Randy

CMac89
07-16-2006, 11:38 AM
I used an o-ringed plug for the injector hole whenever I did testing.

Randy's work will help the intake flow out a pretty considerable amount, but still won't have the full potential of a runner type intake. It isn't Randy's fault, it's Ford's for making such a great intake, lol.:rolleyes:

On other heads I have always built them to flow the same with the intake on as they do with the intake off. So I get what numbers I can and then start on the intake until I match the head flow. Now since we have the SC intake manifold there really isn't much you can do about it other than do what good work Randy has done.

A head on a flow bench determines what will happen under boost with minimal differences. Just because there's more air from boost going through the intake doesn't mean that it overcomes every obstacle and margin of error in the intake manifold. Take what turbulence there is on a flow bench in the whole intake design with the port into play and then put 15psi from an M90 on it.

Imagine if it were life sized and you lived inside the intake. You thought Hurricane Katrina was bad.:eek:

seawalkersee
07-16-2006, 12:39 PM
Oh...and frit...water is compressable...10% at 10,000 lbs to be exact...

Chris

fturner
07-16-2006, 01:34 PM
Oh...and frit...water is compressable...10% at 10,000 lbs to be exact...

Chris

Wonder if I can get the M90 to hit that :eek:

Frit

XR7 Dave
07-16-2006, 03:18 PM
I used an o-ringed plug for the injector hole whenever I did testing.

Randy's work will help the intake flow out a pretty considerable amount, but still won't have the full potential of a runner type intake. It isn't Randy's fault, it's Ford's for making such a great intake, lol.:rolleyes:

On other heads I have always built them to flow the same with the intake on as they do with the intake off. So I get what numbers I can and then start on the intake until I match the head flow. Now since we have the SC intake manifold there really isn't much you can do about it other than do what good work Randy has done.

A head on a flow bench determines what will happen under boost with minimal differences. Just because there's more air from boost going through the intake doesn't mean that it overcomes every obstacle and margin of error in the intake manifold. Take what turbulence there is on a flow bench in the whole intake design with the port into play and then put 15psi from an M90 on it.

Imagine if it were life sized and you lived inside the intake. You thought Hurricane Katrina was bad.:eek:

So basically you agree with me that if the manifold is choking flow at a certain point based on flow bench testing then I should be concerned that the same thing is happening when the motor is running in real life?

Randy N Connie
07-16-2006, 03:29 PM
So basically you agree with me that if the manifold is choking flow at a certain point based on flow bench testing then I should be concerned that the same thing is happening when the motor is running in real life?

I agree also. Randy

boostedbird
07-16-2006, 03:32 PM
I agree also. Randy

AAAWWW me too like my opinion would even matter haha
:D

Super XR7
07-16-2006, 03:55 PM
If the 3.8 only had good heads and manifolds these engines would be WOT engines. The heads are weak and the intake manifolds are crap.
I started designing a new manifold but since have put the project on the back burner for the 4.5L. The manifold lacks the bolt holes, plenum, coolant passage and velocity rings were the runners go into the plenum. As you can see this manifold would require a cowl hood.

Mike

CMac89
07-16-2006, 04:40 PM
Yes I entirely agree. Not an agreement based on opinion, but none other than fact based on what you or I have found.

I understand why Ford built it the way they did. They had to have a way to mount an inverted type blower to fit underneath the stock hood. Then they have a return plenum bringing air into the back of the intake because there's really no other way to get the blower mounted in a good spot and have air entry overhead.

The thing is that we would have to (for terms of an SC) invert the blower to make a runner type manifold because it is most efficient to move air into the cylinder from directly above. Like a carbureted motor.

Super XR7
07-16-2006, 05:50 PM
If the 3.8 only had good heads and manifolds these engines would be WOT engines. The heads are weak and the intake manifolds are crap.
I started designing a new manifold but since have put the project on the back burner for the 4.5L. The manifold lacks the bolt holes, plenum, coolant passage and velocity rings were the runners go into the plenum. As you can see this manifold would require a cowl hood.

Mike

One other note and almost forgot to mention but this would also need to have a water to air intercooler in the plenum.

Mike

David Neibert
07-16-2006, 09:59 PM
Dave I also have the same type of porting done to my heads and now the intake too it was hard to get to that big with the foredom but I got it done and I just had a ? for ya I know you probably noticed that the felpro intake gaskets do not fit but have you tried the victor reinz intake gaskets? I too was having gasket fitment probs but the victor fit almost like it was made for ported heads and intake!!!:D

Chris,

Never heard of those gaskets...Wade Embree/ ESM has the pattern because he made the manifold and did the oversized intake ports on the heads. He just makes me a new set of gaskets whenever I need them, so it hasn't really been a problem. Just a little pricey.

David

David Neibert
07-16-2006, 10:11 PM
Are you still using that MP IC tube plenum adapter,restricter plate?


Randy,

Yes I'm still using it, but when Dave reworked the return plenum for the AR, he also removed the choke point near where it was indented to clear the stock fuel rail, so it's probably flowing better than it was.

At this point I'm happy with the performance I've already got, so I have no plans for additional work on the motor. I just want to get the fuel supply issues resolved so I can use some nitrous at the Shootout.

David

seawalkersee
07-16-2006, 10:31 PM
If the 3.8 only had good heads and manifolds these engines would be WOT engines. The heads are weak and the intake manifolds are crap.
I started designing a new manifold but since have put the project on the back burner for the 4.5L. The manifold lacks the bolt holes, plenum, coolant passage and velocity rings were the runners go into the plenum. As you can see this manifold would require a cowl hood.

Mike
How long do you think those runners are? Or how long did you design them to be?

Chirs

Mike8675309
07-16-2006, 11:29 PM
Interesting Wiki article. No time to read it all now.
http://en.wikipedia.org/wiki/Cylinder_head_porting

CMac89
07-17-2006, 09:52 AM
I know a guy that runs a Modified SuperStocker and he has a 272(4.4L) cubic inch NA V6 and he made 699hp at 10000RPM. He runs 9.50's. Now tell me that it takes a blower or a V8 to make that power with a small motor. It was a canted valve GM head with a tunnel ram sheet metal intake and a 1.100" lift on the intakes. Throw an M90 on it and you can get 50 more crank hp out of it.:D j/k

XR7 Dave
07-17-2006, 11:12 AM
:eek: :eek:

XxSlowpokexX
07-17-2006, 12:43 PM
So basically you agree with me that if the manifold is choking flow at a certain point based on flow bench testing then I should be concerned that the same thing is happening when the motor is running in real life?

I 100% agree that under non boosted applications (idle and partthrottle) yes. WHen under boost not so much of a concern. But I'm just repeating myself anyways at this point..Maybe we can build a tunnle ram intake..stick the m90 on top of that and see....In my opinion there comes a point where the amount of work it takes to make a min gain just isnt worth it. Just from a standpoint of runner desighn in boosted vs non boosted applications especially with a blower that makes its boost down low. Its a waste. Again perhaps more plenum, space would help if we were to rev the #@!$ out of this motor. The runners I dont see playing such a major role at high RPM's under forced induction. And we are limited to desighn as has been said. Ideally youd want to shoot the air straight down in apancake type intake. So most important is to get the heads to flow close enough across the board then work on getting less turbulence in the intake...And lastly perhaps more plenum volume. This is what has been attempted (or accomplished I dont know) in the past by many here.

XR7 Dave
07-17-2006, 01:18 PM
Just from a standpoint of runner desighn in boosted vs non boosted applications especially with a blower that makes its boost down low. Its a waste. Again perhaps more plenum, space would help if we were to rev the #@!$ out of this motor. The runners I dont see playing such a major role at high RPM's under forced induction. And we are limited to desighn as has been said. Ideally youd want to shoot the air straight down in apancake type intake. So most important is to get the heads to flow close enough across the board then work on getting less turbulence in the intake...And lastly perhaps more plenum volume. This is what has been attempted (or accomplished I dont know) in the past by many here.

Damon, you are not understanding what I'm saying at all.

My point all along has been that the intake manifold chokes airflow at over .500" lift. It's not that the manifold can't flow more air because it does at lower lifts. It's when airspeed reaches a certain velocity that turbulence seems to start to impede flow. If airspeed is impeding flow then it follows that airspeed will be artificially increased even more to overcome the reduction in flow which may well be causing even more turbulence and more airspeed. I have done numerous simulations and I am starting to come more and more to the conclusion that this phenomenon is a big problem with these motors. Our motors simply do not live up to the expectations of even professional and detailed engine analysis software.

You are an excellent example. You have an intake manifold that is totally different than everyone elses and you claim to have reached 500rwhp through an automatic transmission with "little or no" tuning. How is that when a properly tuned motor with similar parts makes "only" 400rwhp? Are you suggesting that the 2.2L blower is that much more efficient that it make 100 more rwhp? I don't think so.

I'm not going to sit here and knock what you have done but if you are being honest about that then you have to provide me with some reasoning as to how you made so much more HP than anyone else. So far the manifold is the biggest difference that I can see.

boostedbird
07-17-2006, 04:08 PM
.

You have an intake manifold that is totally different than everyone elses and you claim to have reached 500rwhp through an automatic transmission with "little or no" tuning. How is that when a properly tuned motor with similar parts makes "only" 400rwhp? Are you suggesting that the 2.2L blower is that much more efficient that it make 100 more rwhp? I don't think so.

So far the manifold is the biggest difference that I can see.

Hey Damon what was and is done to the manny that you had on the car??? Do you still have it are you looking to sell whats the dealio??

Tickler
07-17-2006, 05:00 PM
Does anyone know how much flow is added by deshrouding the valves?

Tickler
07-17-2006, 06:31 PM
nevermind, i found the answer. 10 cfm right?

XxSlowpokexX
07-17-2006, 08:34 PM
The blower blows through a liquid to air IC and then directly into teh lower intake. The lower intake is a factory peice with the top cut off with short runners blended in. I'm keeping the setup if it is ever RE finished... Thats a whole other story.

Yes that design is more ideal then what our car has from the factory. Just look at where the air has to go before even reaching the intake port.

Personally I feel the extra headwork (more then the top steig setup), high performance coatings throughout the motor, the 2.2 blower with huge oval TB and inlet and intake manifold/IC design all lead to making more power with my setup. I dont think its any one thing.

All I am really saying is that lack of plenum volume will kill you at high lift/RPM more then adding a runner which will help low end power numbers.

I think we are all on the same page when it comes to the lower intake not providing equal distribution...But again under boost it will be a different story.

CMac89
07-17-2006, 09:11 PM
I 100% agree that under non boosted applications (idle and partthrottle) yes. WHen under boost not so much of a concern. But I'm just repeating myself anyways at this point
How isn't it a concern? If you honestly think it gets better under boost it doesn't it gets worse. What results you get that hurts through a flow bench is inflated as it is boosted. Why do I say this? Because I've done many tests that prove it.


Maybe we can build a tunnle ram intake..stick the m90 on top of that and see....In my opinion there comes a point where the amount of work it takes to make a min gain just isnt worth it.
A tunnel ram will help and it wouldn't be minimal as it isn't in every application that I have worked on whether it be V6 or BB/SB V8's. This doesn't have anything to do with opinion. Science is science. That's like saying, "in my opinion I think the world is flat."


Ideally youd want to shoot the air straight down in apancake type intake. So most important is to get the heads to flow close enough across the board then work on getting less turbulence in the intake
No you don't. There isn't any airspeed gain in a straight open pancake type plenum so it doesn't work. What work is an open plenum built on top or runnersThe way I have built heads for forced induction the airspeed is higher inside the port through the RUNNER than it is coming out of the blower, turbo, etc... The more velocity you get the more power you make and theres no other way to do that then using a certain lengthed runner.


...And lastly perhaps more plenum volume. This is what has been attempted (or accomplished I dont know) in the past by many here.
This is true, but on top of a runner.

Sorry to break apart your post, but I wanted to stay as clear as I could.:o

XxSlowpokexX
07-17-2006, 10:32 PM
It's ok I understand. Let me just better explain myself Cmac


Why do I say this? Because I've done many tests that prove it.


Typically an engine draws air through the intake not forcing it through...So it is a completely different scenario. A flow bench does not take the whole system as desighned into play. And we all know its about combinations..Not just one part. Just explain to me what type of testing you have done comparing a pancake type intake to one with runners and then varous sizes and lenghts. You dont have to explain to me the theory of short vs long runner as I know where they come into play. Just what kind of tests?


That's like saying, "in my opinion I think the world is flat."


When I say in my opinion...

In order to even think about using a runner type intake on our cars youd need....Runners....An IC on top of that..Then the blower itself....About 6 inches later and a promod hood scoop you may have that setup on our car. Is it worth it in My opinion....NO


The more velocity you get the more power you make and theres no other way to do that then using a certain lengthed runner.


Very true as runner lenght and plenum volume all have a great deal to do with where yoru powerband will lie and fall. However again..In order to do this on our car?...Not going to happen. When I said Ideally youd want to blow directly into the pancake manifold I meant that when compared to what we have now.


I dont disagree with runner/plenum theory at all.

But we arnt building a racecar. Our options are limited to space and ford compramised. I think all talks about what we can do would be more fruitful then what would be optimal....WHat we need to do is what can be done optimally under our parameters....

And is the amount of work worth teh extra power KNOWING full well we cant utilize a full runner manifold on our application unless we want a promod hood scoop

XxSlowpokexX
07-17-2006, 10:37 PM
One other thing about compramising. We need to compramise our design just as Ford had done. I am an engineer by trade. It is real easy to build something optimal....Not so easy to build it under parameters that restrict you...We have certain parameters that restrict us, space being the major one.

XR7 Dave
07-17-2006, 10:50 PM
I think I have a solution. I'll let you know if it works. I'm not going to post it here until I know if it works because I don't do well with criticism especially when I'm in the design and testing stage, Damon. :p

XxSlowpokexX
07-17-2006, 11:53 PM
Dave,

I wouldnt criticize you unless it was constructivelty. Any improvement that is worth the $$$ and can fit under a stock hood would be great...Even a cowl hood. Just my "opinion" of course

seawalkersee
07-18-2006, 07:20 AM
Wow...all that knowledge and I still cant figure out how to make the quote seperate like that...

Chris

CMac89
07-18-2006, 10:21 AM
Yes Damon, as I have said, I understand that we have to put some realism into what we can and won't be able to do with our cars. That is why I said Ford made that intake manifold simply to make everything adapt, not for any level of performance simply other than tree stump pulling.

The tests I have done are on high HP forced inducted motors. We did testing on a 426 Hemi motor with the heads and intake castings that we made. The intake manifold IS an open plenum, no runner design intake manifold because my old boss swore that it would work better than runner type manifolds. We simply did velocity tests between the open plenum and runner type intakes. We probed out the highest airspeed without restricting any intake flow in the runner style intake and as there isn't anything to do with the open plenum type manifold we left alone. The air speed was near 2/3rd's the speed of the runner type manifold.

Okay, so maybe theres some doubt in somebodies mind about flowbenches so lets take it to the dyno. I forgot to say that this motor is using a Weiand 14-71 with 15psi. It made 1760hp with the runner type intake and 1580 with the open plenum design. And get this, we had to take away 8* of timing to get a full test out of it. Detonation to the max.

boostedbird
07-18-2006, 10:42 AM
Yes Damon, as I have said, I understand that we have to put some realism into what we can and won't be able to do with our cars. That is why I said Ford made that intake manifold simply to make everything adapt, not for any level of performance simply other than tree stump pulling.

The tests I have done are on high HP forced inducted motors. We did testing on a 426 Hemi motor with the heads and intake castings that we made. The intake manifold IS an open plenum, no runner design intake manifold because my old boss swore that it would work better than runner type manifolds. We simply did velocity tests between the open plenum and runner type intakes. We probed out the highest airspeed without restricting any intake flow in the runner style intake and as there isn't anything to do with the open plenum type manifold we left alone. The air speed was near 2/3rd's the speed of the runner type manifold.

Okay, so maybe theres some doubt in somebodies mind about flowbenches so lets take it to the dyno. I forgot to say that this motor is using a Weiand 14-71 with 15psi. It made 1760hp with the runner type intake and 1580 with the open plenum design. And get this, we had to take away 8* of timing to get a full test out of it. Detonation to the max.


NICE!!!!!:eek:

CMac89
07-18-2006, 10:44 AM
I'm glad someoen besides me finally said that we wont be using an true runner type intake desigh. We should keep the discussion to whats doable. We couldnt use a 6" runner intake let alone a 9". Thats what I have been saying all along. Its really Moot.

I do not agree with the "timing " theory.

Valve placement, combustion chamber design and piston design along with camshaft specifications play the utmost role in efficiency and the amount of timing that can or needs to be utilized. Thats how they get 11:1 motors to run on pump gas and produce great HP. An intake is merely built to work in the sweet spot of the motor. Thats where the runner desighn/ lenght and plenum volume come into play. Of course its a very important part of the package as a whole but overall efficiency especially when it comes to timing has to do with what I mentioned above

I personally on small displacement v8 engines have gained upwards of 50rwhp (On a supercharged car) by going from a long runner intake to a short runner large plenum volume intake. I had however lost power below 3,000 rpm's. Good for a race motor..Bad for a street motor.

Do I build race motors on a daily basis ..No..Have I ever built a "race motor"...No..But in the last 20 years I have built plently of powerful street motors and I have alot of experience when it comes to power production vs streetability.

Gaining 55hp at lets say 4,000-7,000 rpm is great on a race motor where you will always be within that rpm.

So if we are going to talk runner design and lenght (not that we can use this information) lets give everyone a realistic view. Where is the HP generated and at what RPM's...And if saying a 55 crank increase at what RPM's and was there a loss at any RPM's. Its all about average HP and torque gains as been alluded to by many here.

I still think we should keep the discussion to what we hav eand what can be done to what we have...Then again we really shoudl stop hijacking this thread and make a new one:O)

This is from the post in non-tech to move it from hijacking. I have done experiments with that too. I may sound like i'm saying that too much, but I am an NHRA/IHRA drag racer and I have to squeeze 2 hundredths of a second out of my car if it means no sleep for a week.

Anyways, out of a stock wedge combustion chamber or a twised wedge from angle plug to straight plug, or from flat top there is what I found a max of 2*. You are right that it is a factor, but small at that. Doesn't mean it got power from more timing, it just changes what RPM is makes power. It is completely standard and well known that the more compression a motor uses the less timing that is needed to be run. As for the length of runners it was an example. I wasn't insisting a 9" runner to be ran on our cars. Every motor is different.

About street performance as opposed to racing is a different story. It completely bugs me that people think that you HAVE to make power at 2500-3500RPM's. Try and tell me that you don't take any motor that has 500-700hp to 6000-7000rpm. If you have an auto with a high speed lockup converter then what the stall speed is would be the lowest RPM you'll see anyways.

My SuperStock motor is a lower RPM motor because of it's stroke which is part of the reason I have to run 9" intake runners. My peak power is 6600rpm and peak torque is 4600rpm. It is the one motor that most resembles the power curve that of an SC. Makes peak torque at a low RPM and more torque than hp, but it's nothing but raw average hp. The curve looks like a plateau. This is because there isn't enough headflow to supply the amount of cubic inches given. I rev this thing to 7200 and the converter flashes to 6400. Runs 9.50's in a 3300lb car and 9.0's in a 2750lb car.

XR7 Dave
07-18-2006, 11:09 AM
I feel that there isn't enough room under our hoods to create anything that would harm low end performance any more than what we already have. The fact is that like Casey said, when you have good hp in the higher rpm ranges, you will find that you zip past the low rpm so fast that it just doesn't matter. Even a stock SC with 3.73 gears will blow off the tires from a stand still, so why do we care if we pick up 50hp more on the low end? Can't use it anyway. Picking up 50hp at 5000rpm though is a huge improvement.

Anyway, from the beginning of this discussion I have only been looking at ways to get the flow out of the stock setup that we need to make use of the flow potential that the heads already have since at this point we aren't even close. I'm not talking about tuned runners at all, I'm just talking about eliminating the vortex or whatever it is that is blocking flow now. I think people are assuming that the stock intake works as well as a pancake intake can work. That is just not so. IMO there is a real problem with this intake that should have been addressed a long time ago. Perhaps it has been addressed by a couple key people and maybe that is one of the answers to why some people make big power and leave others scratching their heads.

I know Jim Demmit's dad worked his intake over, and I know Coy has spent some time inside his. I know that Bill McNeil made some pretty big power numbers and I know that Tom Morana spent a lot of time in his manifold. David Niebert has a custom intake manifold and Kevin says that his was extrude honed, not sure what hand porting it has....

Anyway, I think there is more to the intake manifold than people are believing. I know that if you take a stock intake and simply port match it to the heads/gasket it won't flow any better than a stock one. There is something to this.

Randy N Connie
07-18-2006, 11:36 AM
Anyway, I think there is more to the intake manifold than people are believing. I know that if you take a stock intake and simply port match it to the heads/gasket it won't flow any better than a stock one. There is something to this.

This is why I have not done a built a motor. The manifold will not
feed a stock head because of the massive turbulance. I have been
trying to make some changes to the manifold for the last three years.
And still keep every thing under the hood.

The manifold that I started on last year should be of some help.
If I am ever able to get out to my shop. I have been able to
widen the RPM power band.This is because of making the plenum
effect larger. But linear flow has been next to impossible with keeping
in the Ford design looks.

I think I have some impovment designs to add to my next manifold.
That will increase RWHP, not to just extend the power band.And
still fit under a COBRA R hood.

I believe that it is possible to have a stock SC 3.8 motor break the 12.9s

Randy

XxSlowpokexX
07-18-2006, 11:44 AM
I'll settle for half that HP :O)

Randy N Connie
07-18-2006, 11:50 AM
I'll settle for half that HP :O)

Damon the raised manifold that I have been refurbishing was Jim Ds
So since it was on Jims car, that alone should be worth .500 ET. :)
And I believe it was fab by Coy M. Another .500 off. :)

Randy

XxSlowpokexX
07-18-2006, 11:52 AM
I do not think that our intake is near optimum. If anything our intake takes away low end power due to design as well as top end HP due to lack of volume. I didnt mention it but Randys adding that extra plenum volume probably doesnt help a stock motor within stock RPM ranges however as he said it extended RPM range thus giving more usable power. And I;m sure with enough work our manifold can be made to work well. But at what cost $$$$ wise. I'm almost thinking it be cheaper to start from scratch and save the aggravation of trying to weld that ~~~ intake.

In the end though its how much $$$ for how much power..Of course knowing myself I'd buy something that works just because..

Randy N Connie
07-18-2006, 11:57 AM
I;m sure with enough work our manifold can be made to work well. But at what cost $$$$ wise. I'm almost thinking it be cheaper to start from scratch and save the aggravation of trying to weld that ~~~ intake.

In the end though its how much $$$ for how much power..Of course knowing myself I'd buy something that works just because..

Damon it only takes me around 250 to 260 hours to modifi
a raised manifold.:confused:

Bolting on my stage I OR stage II helps a stock motor.
And also the raised manifold StageIII with a larger
plenum volume in the manifold.

XxSlowpokexX
07-18-2006, 12:01 PM
Randy,

Thats exactly what I'm talking about...How about we get some stock and built one out of sheet metal :O)

Randy N Connie
07-18-2006, 12:05 PM
Randy,

Thats exactly what I'm talking about...How about we get some stock and built one out of sheet metal :O)

I plan to this year. But it will be for racing only.Because of size.
I bought the materials last year.I have finished the machine
work on the manifold flanges, that bolts to the heads.

David Neibert
07-18-2006, 12:15 PM
Randy,

Thats exactly what I'm talking about...How about we get some stock and built one out of sheet metal :O)

Just ask George to post some pictures of his.

David

Super XR7
07-18-2006, 12:25 PM
I will revive the manifold project if there are people interested in it, which sounds like there is. I will work with one or two people in the design phase, If interested let me know.

Mike

XxSlowpokexX
07-18-2006, 01:07 PM
I saw Goerges pictures but that is far from a factory application intake! Unless your talking about something different? The whipple ESM project right?

Nettlesd
07-18-2006, 01:27 PM
I will work with one or two people in the design phase, If interested let me know.
Mike

Oh, Oh, pick me, pick me. Wait a minute, what's a SC manifold and what does it do? :)

CMac89
07-18-2006, 01:32 PM
I will revive the manifold project if there are people interested in it, which sounds like there is. I will work with one or two people in the design phase, If interested let me know.

Mike
Work with people in terms of design ideas or materials/fabrication?

XR7 Dave
07-18-2006, 01:37 PM
Mike has the tools and materials, I think he's looking for help with the design. Casey you could be a big help in that department.

Geez, so many things to do...so little time.

David Neibert
07-18-2006, 01:38 PM
I saw Goerges pictures but that is far from a factory application intake! Unless your talking about something different? The whipple ESM project right?

Yes the ESM whipple project. As I recall the intake manifold includes runners and provisions for a liquid IC core, but it was very tall.

Just thought it would be helpful to see how the runners were located ect..ect.

David

Ira R.
07-18-2006, 01:47 PM
In the end though its how much $$$ for how much power..Of course knowing myself I'd buy something that works just because..

Come on Damon, that is always the issue. But at 400 hp we are no longer talking about your average street application, and even less so at 500plus. (except for David of course ;) )

We all know you can reach 300hp using a variety of options and do it relatively inexpensively. But as this one discussion has pointed out, these engines were just not designed to do too much more. Even with all the modifications being done, there are still only a handful of 400+ hp cars out there.

I think at this stage we are well passed the point where the solution must be "cheap enough to fit under the hood", and I would like to hear much more discussion about the engineering options than the financial ones. Building an engine that will stay together with 500 usable horsepower has never been cheap, no matter the manufacturer.

On another note, I was glad to hear someone mention that the power curve at 2500-3500 rpms is not an issue here. Good for you. With all of our torque down low, it's just another street application for getting on the highway and has nothing to do with top end horsepower.

I now return you to the people who know what they are talking about

Ira

XxSlowpokexX
07-18-2006, 02:46 PM
Ira,

If 50 even RWHP is going to equal 6 inches in heights...I'd pass.....But I been known to buy almost anything that works...So who knows what I'd do if it were available. Still for it to be of interest to most it have to at least fit under a cowl hood..Whatever it may be

CMac89
07-18-2006, 04:21 PM
That's why they put the word "dedication" inside the dictionary.

92strokedbird
07-18-2006, 04:23 PM
How long would the runners need to be on a runner plenum for our cars for optimal performance.I have a design idea that might work.:rolleyes:

XxSlowpokexX
07-18-2006, 04:35 PM
Stephen,

Its really experimental.

92strokedbird
07-18-2006, 04:46 PM
Why not drop the intake plenum down into the area between the heads and fabricate rounded arc type runners that extend down if needed for length.This would not only enlarge the plenum but may be a fix for installing runners as well.Just a thought.

XxSlowpokexX
07-18-2006, 04:56 PM
The only problem we run into when trying to create any type of a runner intake with a semi stock type setup is that we have a rear mounted inlet

XxSlowpokexX
07-18-2006, 04:58 PM
The only problem we run into when trying to create any type of a runner intake with a semi stock type setup is that we have a rear mounted inlet. Keeping equal lenght runners would be an issue unless we can somehow experiment with different diameter /lenght runners tuned per cylinder ..I really have no answer on that though

92strokedbird
07-18-2006, 05:21 PM
The rear inlet might not be a hinderance under these circumstances.Since the inlet would fill the plenum over the runners and the runners would draw air down to them.It would not make the plenum any higher so there would not be any hood clearance problems at all.

Ira R.
07-18-2006, 06:48 PM
Ira,

If 50 even RWHP is going to equal 6 inches in heights...I'd pass.....But I been known to buy almost anything that works...So who knows what I'd do if it were available. Still for it to be of interest to most it have to at least fit under a cowl hood..Whatever it may be
Yea, maybe, maybe not. You haven't convinced me you wouldn't do it anyway just to see how it worked out :p

Come on, stop making this sound like a discussion between buying a Yugo and a Shelby and put your engineer hat on and jump in. It may or may not be affordable, but that's not the point - and you know it ;)

Aha, I see that you have. Good.

Ira

Slysc
07-19-2006, 10:04 AM
If just a bit more runner length and a better transition into the head port will make the difference, maybe my turbo intake is going to help me get the most out of the .600 lift cam that I ordered. I guess untill I get that finished, the cam probably won't help me eh?

Here's a picture of the turbo intake in progress.

David Neibert
07-19-2006, 11:54 AM
Dan,

Where do you plan to mount the throttle body ?

David

XxSlowpokexX
07-19-2006, 02:06 PM
I think if I recall correctly at the front

Slysc
07-19-2006, 03:12 PM
Yes,
The plan is to seal off both ends to make a plenum, then mount the throttle body to the front. The MAF will be the Pro-M draw through that I'm currently using. Single turbo mounted in front on the passenger side blowing throught my current FMIC but in the opposite direction as it currently flows. That will put the pressure side flowing directly where my current blower exit is.

seawalkersee
07-19-2006, 04:28 PM
How much longer is that gonna take?

Chris

Mike8675309
07-20-2006, 10:31 PM
Interesting discussion on intake manifold design and an engineer playing with modeling tools for a Mitsu Evo engine.
http://forums.evolutionm.net/showthread.php?t=196546&page=1&pp=15

CarlisleLandOwn
07-21-2006, 03:57 AM
http://www.sccoa.com/forums/attachment.php?attachmentid=21483&d=1153317842

I really like that idea. Just as an eyeball it looks like it SHOULD have enough plenum volume and it definatly has some runner to it. I can't wait to see the finished produc, should be really nice. If this is going on a turbo car has anyone thought about the dual runner setup? It would help keep velocity up giving you more power down low off boost which would be nice in day to day driving.

I have a decent amount of experience in multiple runner intake manifolds, and honestly, while they have their shortcomings on an all out racing motor, in every day driving they are really nice. Sort of like the Q-Jets from back in the day. ;)

XxSlowpokexX
07-21-2006, 12:18 PM
The shortcommings of a design such as that (short runner large plenum) is loss of low and mid range power. And has been said..Ok for a race engine in which you stay at higher RPM's...Not so great on a street car where you spend alot of time at mid and low RPM's

Also any vacuum secondary type carberater when properly tuned works great for giving low end driveability when compared to a double pumper type carb....I like variable venturi carbs myself.

Super XR7
07-21-2006, 12:24 PM
The shortcommings of a design such as that (short runner large plenum) is loss of low and mid range power. And has been said..Ok for a race engine in which you stay at higher RPM's...Not so great on a street car where you spend alot of time at mid and low RPM's

Also any vacuum secondary type carberater when properly tuned works great for giving low end driveability when compared to a double pumper type carb....I like variable venturi carbs myself.

In your opinion how long should the runners be for a street performance car that gets raced once a month? Min - Max

Mike

XxSlowpokexX
07-21-2006, 06:01 PM
Mike,

I have never done any engine modeling so I cant really give you an answer as to what is ideal. I can tell you that I have personally lost upwards of 50rwhp down low with a design sim to that in which I used a factory type lower intake witha breadbox type upper. But the minute boost came on the lost RWHP would come back and then some. So as I was saying on a race car in which you keep the revs up it isnt a big deal. On a street car you can have slight drivability problems and sluggishness down low.

As was alluded to before the new Trick Flow short runner intake took this problem into consideration and added extra runner lenght designed in such a way to improve low end yet still gained top end by added plenum area.

Now if you took the factory N/A lower and shortened the runners on the factory upper while adding a larger plenum area to the end....Or even trying to simulate the desighn of that new trick flow v8 ford intake...Youde do much better then just adding a box on top .

Sorry i cant be of more help but I do reccomend checking out the way trick flow blended in the runners on teh upper intake by spreading them before going into an open plenum area.

Damon

Randy N Connie
07-21-2006, 06:03 PM
The shortcommings of a design such as that (short runner large plenum) is loss of low and mid range power. And has been said..

I think a Smaller blower pulley would take care of most of that.
Since we are not running a carb'ed motor.

And its not a problem to add some runner length inside of a
modified stock casting.

Randy

XxSlowpokexX
07-21-2006, 07:01 PM
Randy ,

I had also alluded that with a roots type blower which gets power down low the difference wouldnt be nearly as much(previously in the post). But Dan is using that for a Turbo motor. You will feel part throttle low RPM power loss without a doubt

CMac89
07-21-2006, 08:00 PM
In our case, since we're using a positive displacement blower the "low end sluggishness" is irrelevant to our cause.

If you have an auto then set the converter where your motor makes power at and your done. With a stick car you just do it with gearing.

Funny how most people on this site don't support street racing, but still want parts that help low end performance ON THE STREET. ***sigh***:rolleyes:

On our cars we don't have the structurability to actually adapt an intake manifold that would get rid of low end performance. We would be going from a horrible intake to a decent, alright, or maybe a good intake. If we can get peak power to upper 6000 RPM then we're in good shape.

Randy N Connie
07-21-2006, 08:17 PM
Randy ,

I had also alluded that with a roots type blower which gets power down low the difference wouldnt be nearly as much(previously in the post). But Dan is using that for a Turbo motor. You will feel part throttle low RPM power loss without a doubt

Your right again Damon.We are all building somthing different.
Me I am just building bolt-on parts, to be as efficant as I can
with stock motor .For Right now. :) Speed will come when or
if I deside to add cam and heads.

Do you think SLY'S axels will hold up off the line,after he builds
enough boost to get his 5 speed flame-in gray goast down the track.

Randy

Randy N Connie
07-21-2006, 08:36 PM
Funny how most people on this site don't support street racing, but still want parts that help low end performance ON THE STREET. ***sigh***:rolleyes:


George does not allow street racing posts. Why,I think its because
his car is to slow to do any street racin .:p :D

Randy

XxSlowpokexX
07-21-2006, 10:31 PM
teh boost will come on at around 2,500-3,000 so dependant on launch he may be ok:O)

XR7 Dave
07-21-2006, 11:36 PM
Discovered something odd. If you ports flow a "little less than the best" then you can get away with .600" lift and not see a fall of in flow. With a port that flowed 227cfm at .550" you get 215cfm through the manifold. Then if you take the same head that flows 230 cfm @ .600 it will flow 205cfm with the manifold on (at .600"). On a head that flows 220cfm at .600" you get 215cfm through the manifold.

Don't know what that means exactly but it is interesting. I'm guessing that it means that flow above 220 cfm is wasted on the intake port because the manifold simply won't flow any more and if you try to force it to it says "uh uh" and digs its heels in. :confused:

white95v6
07-22-2006, 12:43 AM
interesting. i guess i need to look around on here alittle more.

have any of you guys seen my intake? i lost only a Few ft/lbs down low. and you never miss it on the street. i have about 2'' more runner then the one pic that was posted. my plenum volume is right at 5.6L.

XxSlowpokexX
07-22-2006, 01:52 AM
You had sent me pictures of yoru intake..Definately had plenty of plenum volume from the look of it and definitely had longer runners then what Dans putting together. We wouldnt have that type of hood clearence though..Maybe not even with the cowl hood on an sc

seawalkersee
07-22-2006, 07:24 AM
Do you have a link that shows your build on that intake Matt? I am very interested in that but how did we get on intakes for sooo many pages? Espically when it is titled Cyl head flow numbers?

Seriously though...Since Matt is here now...What are your head flow numbers? The current ones, not the ones being done. How many more cfms are you looking to gain with your new setup?

Chris

white95v6
07-22-2006, 08:17 AM
http://www.v6power.net/vb/showthread.php?t=25303&page=2

on the 2nd page you can see the intake. there is a few side shots and i think one Front shot of it.


also my old heads Flowed around 190cfm on the intake and 145 on the exhuast with Stock single port valves. my new heads are gonna flow Alot more. :cool:

seawalkersee
07-22-2006, 06:07 PM
Were they all 190 cfm? If so...have you tried it with the intake bolted on them?

Chris

white95v6
07-22-2006, 06:56 PM
they all flowed with in 4-6 cfm of each other. and no i did not Flow them with a Lower bolted on.

Randy N Connie
07-23-2006, 09:44 PM
After well over two years of work I have a modification to
greatly enhance are stock manifolds linear flow into the heads.
This is the problem Dave is now seeing.

Will post some pictures and info very soon. Right after the
completion of upcoming SC/XR7 2006 Shootout.

Dave D. Thanks for your help in testing the raised manifold .
and the numbers in your last few posts.

Randy:)

Jason Wild
07-23-2006, 09:53 PM
Has anyone looked at making an intake thats like the one found on the mark 8I was trying to draw it in cad but I was haveing some problems with my program. I will try again.

Slysc
07-24-2006, 04:28 PM
[QUOTE=DamonSlowpokeBaumann]The shortcommings of a design such as that (short runner large plenum) is loss of low and mid range power. And has been said..Ok for a race engine in which you stay at higher RPM's...Not so great on a street car where you spend alot of time at mid and low RPM's

The 4.2 NA upper and lower intake manifold like you see in the later Aerostar vans have a cool crossover intake manifold very similar to the BBK 5.0 intake. Those runners are pretty long. That would probably make a good manifold if one were to run a turbo or a centrifigal blower. If you do the calculations, my runners are still too short for optimal low end on a N/A motor but I figured I was getting a much longer runner than the SC intake.

Darkside
03-20-2008, 05:27 AM
So I was reading through this and was curious if any solutions for the "turbulence" were ever found? Or was it just decided that for the majority of people it makes more sense to leave the intake alone, unported(gasket-matched) even.