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stempak
09-21-2007, 09:33 PM
can I use used roller rockers? I 'm sure I'd want to replace the pushrods

David Neibert
09-21-2007, 11:53 PM
Yes you can use roller rockers, and you can replace the pushrods if you want to but it isn't necessary unless changing the cam to one with a smaller base circle.

BTW..why are you wanting to install roller rockers ?

David

panic
09-22-2007, 07:19 PM
I haven't gotten an answer to this from either owners, manufacturers, shops, etc.
A roller tip effectively lengthens the valve stem by the roller radius (compared to an OEM rocker with the same contact point), which may be as much as 3/16" (3/8" roller tip is common).

The question: is compensation for this built in to the rocker design (viz. the rocker axle is located lower)?

Flex
09-22-2007, 07:52 PM
Aside from the reduced friction and corresponding temperature drops, roller rockers are precisely machined to maintain exact ratio. Try and say that about the factory stamped sled rockers.

Unlike sled rockers, the ratio does not change through the range of motion either. Seems like good reasons to me.

stempak
09-22-2007, 08:43 PM
They free up hp in the upper rpm's and just less friction better on valvetrain. They are a much better design. But unfortunatly very expensive for these cars brandnew.

David Neibert
09-22-2007, 08:55 PM
Aside from the reduced friction and corresponding temperature drops, roller rockers are precisely machined to maintain exact ratio. Try and say that about the factory stamped sled rockers.

Unlike sled rockers, the ratio does not change through the range of motion either. Seems like good reasons to me.

If doing ported heads and a more agressive cam, yes I would upgrade the rockers and pushrods too. But just doing rockers and pushrods for increased HP on an otherwise stock motor isn't something I would reccomend. Mainly because it's not going to make any noticable increase in power.

There are many other things that can be done to increase power before pulling the rocker covers.

David

Flex
09-22-2007, 11:58 PM
David,

I have heard that argument before and I say bull. These are the same stamped steel rockers Ford used on the 351C/M/400 and 429/460. They suck. My Clevelands had over 20 thou variation in lift across the set. Your .500 lift cam is now a .480 on one cylinder and only a handful were actually 1.73. The ratio on a sled rocker also changes as it moves through it's arc. Not so with a roller.

Stempak,

Search the boards for lightly used ones. I just bought a set of 1.8's that are adjustable CSP pieces for $175 shipped to my door.

panic
09-23-2007, 12:03 AM
The only way the ratio on a rocker, any rocker, regardless of construction or ratio, will not change during its range of motion is if its length is infinite.

Flex
09-23-2007, 12:19 AM
This is directly form the Ford Performance Handbook page 221. Here they are talking about a 5.0 rocker.

"The rocker arm ratio on a non GT-40 engine varies mechanically, due to the design of the sled-type OE fulcrums. At the point of maximum lift, the (sled type) rocker ratio is effectively 1.59:1. This number is commonly rounded off to 1.60:1. At points of less than maximum lift, the sled fulcrums and the slotted rockers cycle the effective rocker ratio between 1.53:1 and 1.60:1. Minor production variations and some flex under load also affect the stock steel stamping's effective ratios. Unlike sled fulcrumed rocker arms, a true roller type (used in the 1993 Cobra GT-40 engine) operates with a constant ratio to provide a definite performance benefit in many applications."

panic
09-23-2007, 12:21 AM
That's very interesting. It's also wrong.

Flex
09-23-2007, 12:23 AM
How so? Some explanation of your reasoning might help

stempak
09-23-2007, 01:36 PM
Anytime you can eliminate metal to metal your gonna get more power. I bet putting on roller rockers you'll get 2-5hp in stock trim!

Flex
09-23-2007, 01:56 PM
In the N/A Mustang forums, that is what most found at the dyno was about 3-5 hp with the 1.73 rollers. The 1.8's cam in at a bit more showing about 7- 10 hp.

David Neibert
09-23-2007, 07:07 PM
Anytime you can eliminate metal to metal your gonna get more power. I bet putting on roller rockers you'll get 2-5hp in stock trim!

There are many things you can do to increase performance. I just don't think spending $175 for rockers plus whatever it cost for pushrods and gaskets, plus about 4 hours labor minimum under the hood is worth a measly 3 HP.

For example you could get 15 HP from a 5% jackshaft pulley that takes about 20 minutes to install. You could get another 15 from a set of underdrives...another 2 from removing the air silencer.

David

stempak
09-23-2007, 07:10 PM
that also! there's alot of hidden hp in these cars!

Flex
09-23-2007, 08:55 PM
David,

That is all true, but in order to use that jackshaft pulley or a 10% OD sc pulley you need to mod the exhaust and or port the heads and or port the blower or you add heat which leads to detonation.

On and on you can make the argument that it is an all at once deal which is a ton of money and time as well. Otherwise you could detonate heavily and blow the hg's etc.

I guess it comes down to individual choice in the end. I am not saying you are wrong in suggesting other mods could have more benefit and take less time. There are those that suggest that there is no benefit and that is what I have issue with.

Mike8675309
09-23-2007, 10:12 PM
David,

That is all true, but in order to use that jackshaft pulley or a 10% OD sc pulley you need to mod the exhaust and or port the heads and or port the blower or you add heat which leads to detonation.




You do not need any mods to use a 10% OD sc pulley. To gain the most advantage for it you may need it, and you certainly don't need to port anything. You may want to, but you don't need.

Remember, the knock sensor will cause the motor to pull timing up to a certain point, so you can get fairly severe with bolts ons before things start going all the way down. People have been bolting stuff on to these cars, without a tune, for a long time and not blowing them up.

As far as roller rockers, I can't see the value myself for a stock motor with a stock blower. But that is me. The items that have me feeling that way are:
#1 - The benefit of roller rockers are seen only at higher RPM.
#2 - Stock SC red line is too low to see a benefit
#3 - The stock blower, even with the stock pulley, let a lone an overdrive pulley is down right inefficient as you go past 4800 crank rpm.

Again, that is what I see. I wouldn't bother with roller rockers until I was looking to go over 300rwhp and was looking at doing head work.

Flex
09-23-2007, 10:21 PM
Mike,

My mods to date are; 10% SC, underdrives, modified FF top and enlarged IC tubes with a ported IC. Some days the car runs good. Some days it detonates pretty bad. Cats are noisy and could be the problem.

XR7 Dave
09-23-2007, 10:50 PM
Nothing wrong with doing roller rockers but as David said, there are easier ways to pick up HP.

I think that one of the first things a person should do is have your blower ported. Even an early style blower does just fine if its ported properly. I'm running an early style blower on my wife's XR7 and it makes 15psi almost instantly and holds it all the way to 5500rpm. I'm overdriving it 15%. Her motor is stock other than a mild cam, heads have never been off the car. It made 257rwhp at the Shootout last year without even any tuning (stock injectors).

Then the next thing a person should do is get a good exhaust. If you have rattling cats you shouldn't even drive the car. If the contents are loose in there then they can plug up which is an almost guaranteed blown headgasket as fast as you can say "Boost".

A good exhaust just means 2.25" pipes and a straight through resonator. It doesn't have to mean headers or fancy pipes. Even the stock pipes from behind the resonator can be used if you need to save money.

Then after that upgrade your IC. Start by putting a fan on it. I always pick up about .2 sec with a fan on the IC. The next step whenever you can spare $100 is to get a shortened AC condenser in there and then start saving for a double or something else. Either way, opening up the airflow to the IC is the cheapest and easiest upgrade you can do.

If people would start with these basic items they would be amazed how well the car performs and how much more consistent it will be even in warm weather.

If your car is detonating then you have issues. Stock SC's do not detonate.

Flex
09-23-2007, 11:04 PM
Dave,

I can hear the cats occasionally rattling that is why I am not driving the car. I am swapping in a Lincoln tank with the straighter exhaust path so I have no choice but to do the back half of the exhaust as well.

I have a 255 high pressure Walbro unit I will put in at that time and an aluminum driveshaft.

What was your wife's car making for boost prior to the porting?

XR7 Dave
09-23-2007, 11:16 PM
Dave,

I can hear the cats occasionally rattling that is why I am not driving the car. I am swapping in a Lincoln tank with the straighter exhaust path so I have no choice but to do the back half of the exhaust as well.

I have a 255 high pressure Walbro unit I will put in at that time and an aluminum driveshaft.

What was your wife's car making for boost prior to the porting?

Porting doesn't increase boost. It allows you to run more OD effectively. I would not overdrive a blower without porting it first.

stempak
09-23-2007, 11:21 PM
Unfortanately these things are not cheap. Like a s.b.c 75bux. But I guarranty if you put them on your car you will notice a smoother motor and noticable power.

CMac89
09-23-2007, 11:25 PM
Unfortanately these things are not cheap. Like a s.b.c 75bux. But I guarranty if you put them on your car you will notice a smoother motor and noticable power.

You just don't take experienced and constructive criticism very well do you?

Flex
09-23-2007, 11:38 PM
Dave,

I understand that aspect of the discussion. I wanted to know if it was overdriven 15% prior to porting. If yes, how much boost did it make? Just trying to judge the perspective gain.

Flex
09-23-2007, 11:41 PM
You just don't take experienced and constructive criticism very well do you?


I don't believe his response is influenced by any criticism. He is merely stating his opinion.

stempak
09-23-2007, 11:44 PM
No I do. But going from metal to metal, to a roller. I mean come on.

CMac89
09-23-2007, 11:52 PM
I don't believe his response is influenced by any criticism. He is merely stating his opinion.

That's exactly what I mean.


No I do. But going from metal to metal, to a roller. I mean come on.

They do help, but the question is, "how much?"

Reduction in frictional losses do add up, but the cure of one alone won't net you plausible gains.

In other motors, I have roller cam bearings in them and it only freed up about 10 crank HP. Worth it to me, but you aren't looking for hundredths of a second. It has other benefits, but that's not the point.

Flex
09-24-2007, 12:37 AM
Yes the hp gains are not huge but roller cam bearings help control oil pressure as well. Combined with the small hp gain, very good reason to use them. I wanted to check if anyone is offering them for the 3.8. Have you used them in the 3.8?

stempak
09-24-2007, 12:43 AM
yes you can get them. their like 400:eek:bux brand new. And like 150 used

CMac89
09-24-2007, 12:47 AM
Yes the hp gains are not huge but roller cam bearings help control oil pressure as well. Combined with the small hp gain, very good reason to use them. I wanted to check if anyone is offering them for the 3.8. Have you used them in the 3.8?

Well that's what I meant by there are other benefits, just a bit off topic to explain and I don't think many care, I think...:)

No, I don't run them in the 3.8, but the bearings I run in my race motors are the same that would need to be run in the 3.8 block. The rear journal on the cam would have to be machined down to a 45mm core size because there isn't enough meat in the block. All of the journals on the block would need to be machined as well. It is expensive too. Either a machine shop has to make the tooling, you have to find a shop that can do it.

Flex
09-24-2007, 12:57 AM
My machinist can do it and is very capable. Trying to decide if the benefits outweigh the costs.

I picked up a set of ARP windage tray studs for the buildup. They end up being approx. 200 thou short as they use a 12 point nut. He is just going to either machine a recess into the cap or mill off that amount from each side of each cap.

thunderkid84
09-24-2007, 08:06 AM
if you're gonna take everything down to the heads off, might as well just pull the heads, port them and get a valve job done. hell, while your at it, throw a cam in. if i were to tear the engine down that far i'd want to put it back together with more than a 3 hp gain.

XR7 Dave
09-24-2007, 09:22 AM
Unfortanately these things are not cheap. Like a s.b.c 75bux. But I guarranty if you put them on your car you will notice a smoother motor and noticable power.
No, you won't have a smoother running motor or more power that you can measure. You might get more valvetrain noise but you won't notice a difference unless you "want to" because people notice differences with all sorts of things including electric bilge pumps hooked up as superchargers.

Seriously, if you want to run roller cam bearings then that's great but I don't think that's what this post was about. Maybe I'm off base, I can't tell sometimes.

SC people crack me up. They are always looking for ways to complicate their road to HP and scoff and mock things that make real differences. This isn't aimed at anyone in specific, just a general observation.

Flex, I did not test the blower in stock form at 15% OD because I feel it is pointless to do so. I was just pointing out that you can make respectable power with an early style blower if you do it right. The 257rhwp was achieved without tuning and through bone stock heads and intercooler (and stock maf, intake and airbox, btw). I now have a slightly better IC and will be tuning the car with 42lb injectors in a couple days because we were completely out of injectors at that time. I hope to make significantly more HP but we'll see.

Flex
09-24-2007, 12:38 PM
Thunder,

From another post.

I am collecting parts for a head swap. I picked up some Felpro MLS gaskets, ARP head studs and windage tray studs, a windage tray from a 94, the 94 heads for a port and larger valve job, ordered custom 7 mm stemmed 1.95 Int and 1.625 Exh stainless valves, bought Comp beehive springs and retainers, a Comp .491 regrind from Dave Dalke, one piece pushrods, 1.8 roller rockers and a set of h-beam rods and coated forged pistons from Paul at BTM.

I am also going to port the 94 Intake. Still looking for a billet double roller as well.

Flex
09-24-2007, 12:41 PM
Dave,

While not directly in line with this post, the roller cam bearings are in line with the reduced friction and better oil control thoughts.

What are you referring to as a slightly better IC? Please let me know what the result of your currrent efforts are after the tune.

thunderkid84
09-24-2007, 05:19 PM
Thunder,

From another post.

I am collecting parts for a head swap. I picked up some Felpro MLS gaskets, ARP head studs and windage tray studs, a windage tray from a 94, the 94 heads for a port and larger valve job, ordered custom 7 mm stemmed 1.95 Int and 1.625 Exh stainless valves, bought Comp beehive springs and retainers, a Comp .491 regrind from Dave Dalke, one piece pushrods, 1.8 roller rockers and a set of h-beam rods and coated forged pistons from Paul at BTM.

I am also going to port the 94 Intake. Still looking for a billet double roller as well.

that sounds sweet. when do u think you'll be done with that ?

a slightly better IC, i guess, would be a double IC or front mount. or maybe a shorter condensor and a fan on the stock IC.

Flex
09-24-2007, 07:16 PM
Valves are being custom made by Manley. They were ordered 2 weeks ago and turn around was 5 weeks. I had ordered enough beryllium copper guides for the build but only ended up getting 8 and right now cannot find anymore. I also wanted to use alloy seats but everyone that sells them is out of stock as well.

A buddy is going to pick up the cam and pushrods from Dave at the shootout and bring it back for me. I already have 3 sets of behive springs and two sets of retainers. I should be getting the rods and pistons from Paul in a few weeks. The machinist is running about 3 weeks behind as race season dies off.

I have a donor block and heads to be ported along with the extra intake etc. also for porting. I doubt I will have it back together before the snow flies.

I also ordered a huge double 12" pusher fan assembly for the car and already have a smaller 8" IC unit.