[jlm69]

I've gone thru some old posts and am still as confused as when I started.

I'm putting together a RAV and trying to narrow down stud selections.
I will be using Comp Cams Gold Rockers, stock RAV guide plates, Jomar stud girdles and Milodon tall valve covers. The engine is being built for a bracket car.

In a 2016 post regarding stud girdles and stud lengths, Tom V made mention regarding a Ford Boss 351 stud from Ford Motorsports with .750" screw-in thread depth with a 2.625" installed height from the bottom of the hex to the top of the stud. I'm not able to locate an exact match to those specs. I even tried the Ford Performance website, but no mention of rocker arm studs.

In my search so far, I found the following & I think one of these is what I'm looking for, but I need some good input from the forum.........

ARP KIT 100-7101 (SMALL BLOCK FORD)
INSTALLED HEIGHT: 1.90"
ADJUSTABLE THREAD LENGTH: 1.00"
SCREW-IN DEPTH: .750"

ARP KIT 135-7202 (CHEVY BIG BLOCK)
INSTALLED HEIGHT: 2.35"
ADJUSTABLE THREAD LENGTH: .850"
SCREW-IN DEPTH: .850"

ARP KIT 334-7204 (CHEVY BIG BLOCK)
INSTALLED HEIGHT: 2.00"
ADJUSTABLE THREAD LENGTH: .800"
SCREW-IN DEPTH: .750"

ARP KIT 334-7203 (CHEVY BIG BLOCK)
INSTALLED HEIGHT: 2.100"
ADJUSTABLE THREAD LENGTH: .800"
SCREW-IN DEPTH: .750"

Like most, I want to make sure I have enough of stud at the top to make sure the rocker is secure with polylocks using the stud girdles mentioned.

[turbo69bird]

II belive Angeles and Mc carthy had the studs part # in one of their books. I know when I used stud girdles I used a 351 ford stud but can’t remember which one it’s been along time since I needed to run that big of a cam that I needed to be concerned w such things. Is this an original RAV? Seems kind of a waste for a bracket car w aftermarket stuff available today but to each his own .
For a killer bracket car I’d use the ole iron lung (turbo) and some D ports and make more power for less, and not worry about blowing it up..
Turbos make killer bracket cars because they are hard ti judge for sand baggers , slow first half comes in hard to end. Messes them up.

Anyway how that info helps a
Little on the studs.

[25stevem]

Why do you just hang and call Butler performance tomorrow.
They have built a slew of these motors and I am sure they have what you need in a ARP brand.

RA4 valves are only a tenth of a inch longer then D ports, so the length you need is more of a concern for running the stud griddle.

[Lee]

Are those the new CompCam rocker arms? I used a set in '21, and they sit higher than expected. Compared to a set of Crower roller rockers I had on hand, I needed a 0.300" longer pushrod - so you MAY need a slightly taller stud as well.

[tom s]

Which V heads are you going to run?If aftermarket I would talk to the maker.Tom

[jlm69]

OK........

So, to answer the questions / comments posed......

1) TURBO69BIRD

I've had the following parts for the last 30+ years and am totally bent & determined to make a go of them.

RAV 303 HEADS
RAV 400 INTAKE
RAV 400 BLOCK
RAV 400 CRANK
ROSS PISTONS
CALLIES RODS
CUSTOM GROUND COMP CAM

2) 25STEVEM

Next stop is to call Butler. To be honest I thought I would try here first, but they did build my short block.

3) LEE

I don't actually have the Comp Cams rockers in hand yet, but rather those are the ones that I was seriously contemplating buying them from Butler for this build.

4) TOM S

As mentioned above.... Original 303 heads.

[Tom Vaught]

If you hurry you can buy the long stud girdle studs here:

https://pitstopusa.com/i-5071597-arp...rs-girdle.html



One set left.

Tom V.

[Dragncar]

Originally Posted by jlm69

OK........

So, to answer the questions / comments posed......

1) TURBO69BIRD

I've had the following parts for the last 30+ years and am totally bent & determined to make a go of them.

RAV 303 HEADS
RAV 400 INTAKE
RAV 400 BLOCK
RAV 400 CRANK
ROSS PISTONS
CALLIES RODS
CUSTOM GROUND COMP CAM

2) 25STEVEM

Next stop is to call Butler. To be honest I thought I would try here first, but they did build my short block.

3) LEE

I don't actually have the Comp Cams rockers in hand yet, but rather those are the ones that I was seriously contemplating buying them from Butler for this build.

4) TOM S

As mentioned above.... Original 303 heads.

That is a very cool, old school build with PMD iron.
Gotta respect it and good luck with the whole effort.

[25stevem]

I am sorry, your building a 5, I read too fast and thought you where building a 4.

[Lee]

"I don't actually have the Comp Cams rockers in hand yet, but rather those are the ones that I was seriously contemplating buying them from Butler for this build." Personally, I'd use Harland Sharp, or Crower, before using the Comps again. I dug out my notes on that build, and not only needed longer pushrods but also had to get longer rocker studs to have sufficient thread engagement.

If you think you really need the stud girdles, then consider going with shaft rockers. I used a set of the Yella Terra shaft rockers last year, bought through Butler. You need to know your valve length/installed height before ordering though.

[blueghoast]

I run a 2-inch stud on my ed- headed 440 with a KRE stud gurtle
And no problems with 2-years of Drag Week. 2nd year broke inner
valve spring that took me out. My 2inch stud was from hex to top.
Hope this helps.

GT

Oh yeah last day of the week too LOL

[turbo69bird]

Originally Posted by Dragncar

That is a very cool, old school build with PMD iron.
Gotta respect it and good luck with the whole effort.

On the one hand I love the build I have a RAV in my car, but at the same time I kinda sweat it every time I run it even if just easy because I dint want to ruin rare parts.
On the other it’s nice for people to be bake to see the parts in action and how they ran. But w aftermarket’s available I’d probably run aftermarket if I was gonna run it hard

[tom s]

If really going to race it I would get a McCarty single plane intake.The factory dual plane intake will be the choke point of the heads.Tom

[jlm69]

Originally Posted by Lee

Are those the new CompCam rocker arms? I used a set in '21, and they sit higher than expected. Compared to a set of Crower roller rockers I had on hand, I needed a 0.300" longer pushrod - so you MAY need a slightly taller stud as well.

Lee....

What was the stud length when you used the CC rockers and what are you using now with the Crower arms? Do you remember?

I don't have my pushrods yet either, so I'm assuming the difference in the construction of the 2 rocker arms (Comp Cams versus Crower) was that drastic that it pushed the rocker arm that much further up the stud???

I'm no expert by any means, but doesn't play havoc on the valvetrain being that much further up the stud and doesn't it place more stress on the stud?

When I get this thing rolling, I'm assuming I'll have it going upwards of about 7-8K RPM's.
A little concerning.

[cgeise]

If the heads are deep enough I would use the .850 thread length into the heads

[Lee]

"What was the stud length when you used the CC rockers and what are you using now with the Crower arms? Do you remember?"

I used ARP 135-7202 2.350” studs for the CC rockers. I also measured them at an actual ratio of 1.72:1. In contrast, the Crower rockers were advertised as 1.70, and I measured them at 1.68:1.

The Crowers are still on the shelf. I just test fitted them on this engine when I saw that I was going to need longer pushrods and studs! The Crowers seem to have closer geometry to Harland Sharp, and the CC's are different. I looked for some photos I took, but can't find them at the moment.

But, yes, the longer the studs and the longer the pushrods, the greater the amount of deflection that can occur. And as RPM increase, the bigger the issue that those deflections can be.

If I were going to build a motor for 8k rpm, I'd be using shaft rockers. Just think of the damage you might have from one bent pushrod, and how much it would cost to repair the resulting damage - shaft rockers would be a good insurance policy IMHO.

A few years ago, I helped a guy with a solid roller cam in a turbo BBC. He was having issues with the valve lash. Long story made short, his stud girdle was tweaking the rocker studs as it was tightened. Granted that his canted valves made this a worse problem, but it made me cautious about using girdles. We left his girdles off, and it ran much better.

[jlm69]

Originally Posted by cgeise

If the heads are deep enough I would use the .850 thread length into the heads

CGEISE.....

The stud screw-in depths vary.

The studs over / open into the intake ports are anywhere
from.7165", .7240", .7250" and .7340", while the exhaust studs are anywhere from
.8720", .8895", .9155 and .9355".

I would like to use a longer 2.350 stud with the .850 deep screw-in depth, but I had a tough enough time trying to get a cleaning (chase) tap in those holes and I didn't get thru without deliberately trying to break thru.

I'm thinking that I may have to carefully break thru and use only the .750" studs.
I would think that anything longer than what I measured will just become a point of turbulence for the incoming charge of air.

Any thoughts on this???

[punkin]

Apologies if this is considered hi-jacking the thread but I expect a set of crowers and stud girdle to arrive later this week. With regard to the amount of stud available for the adjusters (poly locks), how much thread should be available?

Thanks...good reading in this thread by the way. Thanks everyone.

[tom s]

Has anything been said how much cam is intended to be used?Solid roller?Duration at 200?Lift?Tom

[jlm69]

Originally Posted by tom s

Has anything been said how much cam is intended to be used?Solid roller?Duration at 200?Lift?Tom

Sorry Tom.

Been a few days since I even looked at this.
I'll have to dig out the cam card and get those numbers for you.
I'll give a go tomorrow.

-------------------

By The Way Tom....

The rear water ports on these heads............Can they be tapped for AN fittings for better crossover head cooling??