Welding floors of exhaust outlet

Snake

Registered User
I picked up a set of heads for a good price. options done to them were like a CRME stage 2. They were ported initially by RGR. After he ported them they were flowed at 190 int 150 exh. Very impressive with the stock valves. Morana did some additional work to them and also has 3 angle valve job w/ deshrouding. The only step that has not been done are the welded floors and reshaping to a D port. I found a welder who has done a few heads and this type of thing but not a SC. How far down the exhaust port will he have to weld and I will probably need all new valve seals. Is this difficult to do. The pictures that I can follow on a steig head does not look so difficult. Can anyone with insite to this with help me. The info would really help. I dont want to jack these heads up.
 
This is how I would do weld build up,& Did on a pair of SC heads.

Take the seat out.

Weld from the seat to about 1.5'' toward the exhaust header.
You need to do weld build-up to raise the port floor to make
a longer and higher shortside radius from the seat to exstending
1.5 + toward the exhaust port flange.Your weld build up & porting
from a side veiw is shape of a tear drop.You want to make the
short side radius have a longer ,gentler curve.

Then port the top of port to match the bottom to your spec.
style porting.

Then machine for new seat,and install seat.

Cut the seat and in to bowl area with a SERDI style cutter.

Then port match bottom of seat cut,though bowl area to match
radius cut.

Then flow test,and reweld and report,until you get the numbers
that will makes you happy.

I have only three pairs of SC heads.And the casting in each head
measured different.So the weld build up and port measurments
will very.This is just a general decription, there is much more to
the job.

Randy
 
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Heres a picture showing down the short turn radius that I welded up as disscussed.
These ports flowed right at 214 CFM @ .500 lift. I'm really happy with the results. Dont forget to deshroud the valves as this helps alot.
 

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Not much ,depends on how much disassembly and machining
and assembly work that you yourself what to do.

Bare heads with seats remove,and you just want weld build
up done.not much.

Randy
 
Can we define not much, for a dissasembled head with seats removed?

How do the seats or new seats go back in???
Are they replaced with oversized seats??? ALways been curious about that...

If you aren't hurting for the work, I also have a local guy that can tig/heliarc that said he would do them, only I am not too sure he would know what he is doing... I did see some of his work, and he does get into some pretty tight spaces working o0n his go-cart racing work, but is this something nayone with good welding skill would do even if not particularly familair with these heads???

PM me if you want!

Thank you sir/ma'am!
 
How much of an improvement will this be with the stock valves? How much would I get with larger valves. I still want it to be a street car. Now it is my daily driver so I would have to send you the spare set off my other car so time is not a factor. And I can get the heads down to nothin.

Chris
 
sizemoremk said:
Can we define not much, for a dissasembled head with seats removed?

How do the seats or new seats go back in???
Are they replaced with oversized seats??? ALways been curious about that...

(ANSWER)
HEAT THE HEADS IN A OVEN ,THEN PULL THE SEATS.SAME FOR
INSTALATION,HEAT IN OVEN THEN PRESS IN THE SEAT.

If you aren't hurting for the work, I also have a local guy that can tig/heliarc that said he would do them, only I am not too sure he would know what he is doing... I did see some of his work, and he does get into some pretty tight spaces working o0n his go-cart racing work, but is this something nayone with good welding skill would do even if not particularly familair with these heads???

(answer)
I would think any one could do it.But there are tricks of the trade in
welding aluminum heads,or brazing iron heads.Just because you
have a welder and think your a weldor dosent mean the job will
turn out well,you may end up with having to perform to much
machine work in getting it all back to spec.Meaning massive warpage
and to much deck material to be remove.And to do it right the weldor
and porter must be the same person.

(answer)
I or any one that does know how to properly do world class port work.
Cannot write down in a post or PM on how to do port work.I cannot write down what took me 37 years to learn.Nor can it be tault in a couple weeks.
To do your own heads right.Start with spending around a min of
$150,000,00 in tools.If you just want some cool street/performance
heads you can do it cheaper.

PM me if you want!

THANKS RANDY
 
Thanks, but I am still waiting to hear what your charge is :confused:

I was just curious becasue I know an old guy that has run his own welding business, and has also spent several years in an auotomotive machine shop. I've seen his work, and it looks good to me, but then again, I would not know what I am doing. This guys specialty is smaller go-cart racing stuf, and it looks like he does work in that area, locally, and perhaps a little over carting message boards...

I trust that the guy can weld, I am just not yet sure if this is something really difficult for someone that can weld. but who is not familiar with these heads....

On the seats, is this somehting I could do myself??? I have access to a powder coating oven (which is actually a pizza oven) Is there a tool for pulling them??? I asssume a press will be used to put them back.

I've been going back and forth on the welded heads thing... I'm already getting a comp valve job, does this work usually screw up demensions on the other side of the head, requiring more machine work?

If you could, let us know what you would charge for welding them, if we send bare heads...

Thanks!
 
I think you missed one of the key points Randy was making. This is not really the sort of thing that you do teamwork on. The one who welds should be the one who does all the work. You don't create artwork by having a different person paint each color in a picture. The end result will not have the same effect.

Another key point Randy was making is that while welded exhaust ports may be cool, they certainly are not required for excellent performance. You have much larger obstacles to performance to worry about than welded exhaust ports. Last time I checked CMSII heads are not welded.
 
XR7 Dave said:
I think you missed one of the key points Randy was making. This is not really the sort of thing that you do teamwork on. The one who welds should be the one who does all the work. You don't create artwork by having a different person paint each color in a picture. The end result will not have the same effect.

Another key point Randy was making is that while welded exhaust ports may be cool, they certainly are not required for excellent performance. You have much larger obstacles to performance to worry about than welded exhaust ports. Last time I checked CMSII heads are not welded.


I understand what he means, but some of us aren't welders, but are hoping that we can do a decent port job if we eat our Wheaties before leaving the Holiday Inn Express on the mornings we work the heads :D :D :D

I don't really understand why two separate people welding the ports and porting the heads would be that bad??? So long as both were involved in the desired shape???

Are you offering to port the exhaust ports you weld also Randy???

I guess things are pointing towards leaving the exhast ports alone.... For now anyways... Perhaps I should just save some money for the nickle and dime stuff when I'm ready to put the motor in...


Thanks!
 
I am retied at the moment!!!And 007 will get his panties in a bind
if I would give a price.

The number one reason to weld the short side radius on any head.
But mostly the SC head is if the seat is standing above the port floor.

Stick your finger in the port.If you feel the sharp side of the seat.
You have a head that would be a good canidate for
raiseing this area.As the air gos over this shape edge of the seat
sticking above the ports floor short side.It makes the air roll,
If you could look at the side veiw of the air it would have a
cinnamon roll look..This takes up room and you will have less
room for the rest of the needed air.

This is the same for any part of the seat that may protroud above
the bowl area.You would want to do weld build up.Then use a cutter
tool that gos into the valve guide as a guide to make the seat,bowl area concentric with the valve,This is very important.Concentric.Lop sided
ports flow pourly.This is the only way to make it centered.You
have gaskets to match other ends of the port.Call in gasket matching
your valves diameter ,seat diameter,to the bowl area diameter.

For the ones that do not have the tooling to build the best port.
You can install larger seats.This will take care of some heads
with bad castings.By installing larger diameter seats.This will
set the seat over farther into the short side raius,thus makeing
the short side radius port floor taller.Then you will be able to blend in
the seat to the aluminum short side radius floor.You can cut
the seat down slightly in a radius shape to blend into the short
side radius floor.You can do the same shaping with the seat
is they are stock diameter.

The larger seat will also take care of low casting areas in the
complete bowl area.Idealy you want the bowl area standing
outside of the inside diameter of the seat.Then machine concentric.

I don't have any more time to set and type, BY.
Thanks RANDY
 
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If I am reading this correctly then you install larger seats and valves and you wont need to weld up the floors? I thiught it was to lengthen the short turn radius. Hmmmmmm....Is not lenghtening the STR better on almost all heads?

Chris
 
seawalkersee said:
If I am reading this correctly then you install larger seats and valves and you wont need to weld up the floors? I thiught it was to lengthen the short turn radius. Hmmmmmm....Is not lenghtening the STR better on almost all heads?

Chris

As I said in an earlier post,I can't write evey thing needed to do
a port in a post.There are more than just one or two or even three
reasons to weld the SC exhaust port floor.Keep in mind when I am
writeing that I may just be talking about an area of .300 x .075
inside of the port at a time.

With the seat standing to high at the beginning of the short side
radius.This is the number one problem to repair.

Port work is just like moding your motor for more power.You make
one change,you then will need to mod two other areas to take the
power from the first mod.Then you need to change onther part,
because of the last two changes.

Yes increasing the diameter of the seat can take care of some bad
castings of the short side radius.Were the seat is taller than the ports
floor.And some low bowl casting areas.This is just one way to help
improve this one problem,sometime 2 or 3.A good casting may not
need much if any welding,to get some good flow numbers.I run stock
heads.But I flow tested three sets to get the ones I use.And the
heads I chose was the heads that came with my SC.:rolleyes:

But now that you have increased the seat diameter.And The larger
diameter valve that gos with this mod.And because the SC head
has a quash combustion chamber .You now will have even more valve shrouding.That now needs to be takin care of inside of the combustion chamber.Although the benifit of fixing the to tall seat on the short
side radius with the installation of a larger seat can out weigh the
extra valve shrouding.And some cases it will not.

The reason to lengthen the short side radius ,and what
other mods that should or may go with this mod.Is a hole other story.


For the ones that plan to do your own port work.I have payed for two
new houses that the eye doctor has lived in.So you might want to
give some thought about safty glasses to ware.

Randy
 
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Chris I have I think answered some of SNAKE questions.

So If you want more info.I would like to go to the performance
forum on the member's side. :p

Thanks Randy
 
Thanks Randy

Yes , you answered all trhe questions I needed to know. Im just going to install larger valves on these already modded heads. The chamber area near valves were unshrouded already. Im not looking to pull all the seats just to weld up the floors, might be a small gain if these heads flow 191 intake and 150 exhaust now. Installing small block Chevy valves 1.84 int 1.60 exh.
 
all this talk of welding the floors I took my heads off and laid them on my diamond plate floor"alluminum'
and welded them to the floor it didnt get me anymore power in fact i cant even get them off the floor!!!!!!!!

is this where the grinding comes in?

I used a big jack and raised the roof but the heads are still stuck to the floor.

should I try a bigger pry bar?

and as for stress relieveing the block this is a waist of time i told all my secrets to the block and even had a 1 on 1 with it and it didnt help,

I can say that the ENZYTE works put a few pills in my oil and the cam got much bigger lots of lift!!!

and I smile alot more- - :D
- -
- -
but on a serius note my heads are much the same as those and they offer great power gains on a modified engine didnt see much improvement of stock motor cam and blower work exh really woke it up and made it actually use the head porting
 

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I think I gotta wait till my check clears with george before he lets me in on that secret randy.

I think manny is drunk as i am now. If you could see how slow I am typing yoou would know.

Chris
 
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