Comp Cams 1.6 ratio Self-Aligning Rockers

[rabidbandit]

Alright, my warrantee just expired...hehehe...it's time for some engine upgrades:) I've been looking at Comp Cams for raocker and found some 1.6 ratio Self-Aligning roller rockers. Now I have a 2002 series block with the roller fulcrum rockers and the alignment girdle. Are these already setup up for the new rockers as far as having 3/8 studs....or do I still have to use the 10mm to 3/8in. conversion kit from ARP. Also...will the new rockers even work with the alignment girdle, or do I even need the Self-aligning rockers because of the girdle? Total lift is about .452 with the 1.6's on a stock cam. I'll dive in to the machining of the heads, spring upgrades, belt drive, and new cam later down the road. Any help would be appreciated:confused: Lastly, does the new ratio effect not only lift, but duration as well?

[Sparky2263]

Comp cams doesn't offer a direct bolt-in. Besides, you'd never want to invest in full rollers w/o converting to fully adjustable valvetrain. You'll be miles ahead down the road by converting now and being able to use standard sbc components.

Yes, increasing rocker ratio increases effective duration. Not a bunch, but enough to make a difference.

[subvelocity]

It's a pretty basic conversion. All you do is pull your rockers, and the aligning pedestal or wathever it's called. Then use the ARP conversion studs (8mm to 3/8") part # 134-7201. Put the new studs and self aligning rockers in, with poly locks, and adjust the preload, I did 1 turn past zero lash. Total job should be about 4ish hours. Keep in mind you'll need to get the older style metal center bolt valve covers, and the stock composite ones won't clear the poly locks.

[rabidbandit]

That's a bummer...nobody makes a direct bolt on for roller rockers? It's crazy that nobody has done it. Just making the stock roller fulcrum rockers in the '02 4.3 have the addition of a roller tip would be nice. Oh well...I guess I'll just do the conversion...also the studs are 8mm not 10mm? wow kinda on the small side. Is there any special thread locker or special proceedures to removing and installing the studs? Had a issues with cooling today as well...bought a 170 thermostat and it kept throwing codes for thermostat failure...went back to stock 195...(winter's comin' anyway)

[Sparky2263]

If you are going to do any decent cam in the future, go ahead and convert to the 3/8" stud. Well worth it in the long run.

[rabidbandit]

so it's an 8mm or a 10mm to 3/8...ordering tonight:)

[Sparky2263]

I tapped mine out to 7/16" coarse and put in old school sbc studs.

I believe yours is 8mm (shaft mounted, right?) and that, IMO, is just too small for serious duty.

[rabidbandit]

Well....not shaft mounted...but a standard roller fulcrum like the comp pro magnum rollers....without the roller tip and they have a girdle that has little half moons that sit underneath the body of the rockers to align them on the valve stem since they are not self aligning rockers. I'll try to post a pic...it's wierd. I guess that's gm's version of doing away with push rod guides?!

[rat]

so it's an 8mm or a 10mm to 3/8...ordering tonight:)
8mm, use the p/n that subvelocity posted. You don't have studs stock, the rockers bolt to the head. You just put some oil on the new studs, and screw them in, i think i went to 33ft/lbs or something.


EDIT: pics of the stock stuff, and comp promagnums: http://community.webshots.com/album/466765008qMgZLp

[rabidbandit]

Now is there any way that I can get around drilling the pushrod hole with the 1.6's or am I stuck pulling the intake and boring them out?

[Sparky2263]

Are the 8mm's strong enough to hold an aggressive cam profile if he goes that route?

Just wondering, 'cause 8mm seems kinda small.

Or am I just too old school being stuck on the 7/16" stud?

[rat]

Are the 8mm's strong enough to hold an aggressive cam profile if he goes that route?

Just wondering, 'cause 8mm seems kinda small.

Or am I just too old school being stuck on the 7/16" stud?

It is fine, the ls1 uses 8mm bolts in an aluminum head. My only concern would be stripping the threads, but with an iron head i don't think it is a problem. I don't think there is much sheer load on them. Any bending load would be held by the shoulder. I have been running the 260ahr on them, with 1.52 ratio rockers for a while now, no problems.

[rabidbandit]

Which is the better choice as far as rocker series...Pro Mags, Gold series? I was hoping that there is a set out there that requires no drilling of the pushrod holes...due to a time constraint, it's my only vehicle and I have only a day to knock it out a week.
I heard that some of the self-aligning rockers have to be machined because the guide washers ride on the keepers instead of just the stem...any info on this?

[rat]

Which is the better choice as far as rocker series...Pro Mags, Gold series? I was hoping that there is a set out there that requires no drilling of the pushrod holes...due to a time constraint, it's my only vehicle and I have only a day to knock it out a week.
I would not run an aluminum rocker on a daily driver, so my vote would be the pro magnums.

[rabidbandit]

Did you have to drill? Couldn't tell from photos in web comm.