Need help choosing roller rocker arm

[Joe R.]

I am still leaning towards using roller rockers. I just hate to leave HP on the table. I saw a post a while back where Joe Lucia mentioned Crower stainless steel roller rockers. Joe, is there a particular part number you would recommend for a L-72? I looked at Crower's catalog briefly, but am not sure which one to pick.

Joe

[Matthew M.]

Re: Need help choosing roller rocker arm

I used crower 73605-16 roller rockers on a 1966 SS 396 Chevelle, they fit under the stock valve cover with no problems. My only issue was that they were noisy. Hope this helps

[Joe R.]

Re: Need help choosing roller rocker arm

Matthew,

Thanks for your input. When you say noisy, did it significantly change the sound of the engine? I would like it to sound fairly close to stock while picking up a few ponies.

Joe

[Matthew M.]

Re: Need help choosing roller rocker arm

The noise is hard to describe but I would not say it was detrimental to sound of the engine. I did not really notice it until my Dad pointed it out then I could hear it but knowing what it was it did not really bother me. If you do end up using rollers make sure you check the valve the train geometery. Stay away from junk/cheap rockers like proform they will break that is if you can even get them on without a problem. Harland Sharps are also a good rocker but I dont know if they have anything that will fit under the stock valve cover. If memory serves me right the only one that would clear was the crower, I dont know if that is important to you or not.

[Joe R.]

Re: Need help choosing roller rocker arm

Matthew,

Yes, I would like it to clear the stock valve covers. I'm trying to preserve the original appearance. I hear that it's a good idea to bend the drippers over flat so that they don't interfere with the roller rockers.

Joe

[Fred Y.]

Re: Need help choosing roller rocker arm

Joe,
I had an interesting thing happen with my 67 400 HP engine last yr.I have owned it since 99 & never had an issue.I heard a very small tick under the R/H valve cover so I had my friend remove it to take a look.It seems that one of the original style rockers was slightly off center,& upon removal it was wearing off to one side so I decided to remove all the originals & put Comp. roller tips on along with new Comp. push rods. Nothing radical mind you but it is nice to have that extra 15 to 20 HP along with a much more effecient rocker for a very reasonable cost. Well,after about 2 hrs. running time I heard a series of much louder ticks.This made me REAL nervous!! We pulled the valve covers off again & this time we found 7 of then 16 pushrods failed at the tips!!(definetely a metal issue) I found out that Comp. does NOT warranty their push rods as there a some "Rubes" out there who cannot adjust them properly. We changed the oil & filter & went with their next set of higher strength rods with no problems at all.Strangely,I have a set of the same push rods in my 390 HP Roadster & they are working just fine??? Go figure. So I guess what I'm trying to say is if you go for the rollers & new push rods,keep an eye & ear on things after you install them as you just never know!!

[Timothy B.]

Re: Need help choosing roller rocker arm

I am no big block guy but what's the matter with new GM push rods and new GM rockers, grooved balls and new nuts. (no pun intended) Install and degree the cam and double check specs and be done.

[Joe L.]

Re: Need help choosing roller rocker arm

I am still leaning towards using roller rockers. I just hate to leave HP on the table. I saw a post a while back where Joe Lucia mentioned Crower stainless steel roller rockers. Joe, is there a particular part number you would recommend for a L-72? I looked at Crower's catalog briefly, but am not sure which one to pick.

Joe

Joe-----


The Crower 73605 that Matthew mentioned are the stainless steel rocker arms for a big block with stock ratio (1.7:1). I have absolutely no knowledge of any noise problems associated with these. I've never heard of it (until now), experienced it or observed it.

Another great roller rocker arm is the Comp Cams Pro Magnum. These are made from 8650 chromemoly steel, have large roller trunnions, are guaranteed for life, and are significantly less expensive than the Crower stainless steel variety. The ones you would need would be #1320-16. Buy a set of these, use them, and if you don't like them, you can always change them back to stock rockers and sell the roller rockers. You won't lose much in the deal. However, I don't think you'll end up selling them. I think you'll have them for a long time.

[Joe R.]

Re: Need help choosing roller rocker arm

Joe,

I'm going to go with the Comp Cams #1320-16. Thanks for the recommendation. Other than flattening the drippers, is there any other mods or parts required to make it work properly?

Joe

[Duke W.]

Re: Need help choosing roller rocker arm

If these are the "roller tip" type rocker arms, you're wasting your money and the expensive roller trunnion type are only necessary on a racing engine that sees continuous high revs, plus I don't think any will fit under the OE rocker covers.

Higher ratio rocker arms reduce valvetrain limiting speed. I'd rather have the few hundred extra revs than one or two percent more peak power and less revs to the valvetrain limiting speed. Same applies to these roller tip abominations - they're heavier than the OE stamped steel rocker, and reduce rev potential.

Of course you can install stiffer springs, but now the cam lobe/lifter interface is more heavily loaded, which could cause durability problems.

There's no free lunch, and the OE rocker arm system is inexpensive and bulletproof for a road engine and light racing.

Duke

[Jamie F.]

Re: Need help choosing roller rocker arm

I have to weight in here. The stock BB Chevy rocker pushrod setup is anything but "Bulletproof". I can't even count how many BB I have seen that ate their rockers, or pushrods.
It is the common cause of so many CE blocks out there. Parts get down in the pan.
The Comp Cam setup does not change the stock ratio, and they are ten times stronger with less friction and heat created. By using their thinner and stronger pushrods you also reduce valve train weight allowing higher RPM potential.
They fit under the stock covers as their profile is the same as stock.
If you ever rebuilt a BB Chevy 90% of stock rockers show some type of galling or uneven wear. Why would you reuse them?
The roller tip alternative is about the same price as a set of stock ones from the General, cheaper if you go through Jegs or some place, and really cheap "insurance"

[Joe R.]

Re: Need help choosing roller rocker arm

Jamie,

Your comments are very interesting. A shattered pushrod is what got me into this mess. Do you know the part numbers for the improved version of the pushrods from Comp Cams?

Joe

[Jamie F.]

Re: Need help choosing roller rocker arm

Joe,
There are two type of roller rockers from Comp Cams, one it the Pro-Magnum that Joe Lucia mentioned and the other is the regular Magnum.
Comp Cams makes two 3/8" pushrod that will perform as well or better than the original performance 7/16" pushrod. So no need to go to these big pushrods. They have the High Energy ones, and the Magnum ones. $42 and $107 respectively.
If you go to the Jegs.com website you can search on all the valve train parts for a 427. I think the pushrods are like $41, and the rockers are like $297 and $159 respectively.
For a street engine the lower price ones are more than enough. If you plan to do some racing, or bouncing your tach off a rev-limiter, go for the over-kill ones!

[Joe L.]

Re: Need help choosing roller rocker arm

Joe,

I'm going to go with the Comp Cams #1320-16. Thanks for the recommendation. Other than flattening the drippers, is there any other mods or parts required to make it work properly?

Joe

Joe-----


I think you will find that if you use the Fel-Pro Cork-Lam valve cover gaskets (5/16" thick), you won't even need to flatten the drippers. I highly recommend the Cork-Lam gaskets. Fel-Pro #1630.

Use the poly lock nuts that are supplied with the 1320-16 rockers; they are about as low of a profile as you will find for this type lock nut. You can't use the stock-type, self-locking style nuts with these rocker arms (or any other roller trunnion rocker arm).

The GM pushrods I previously recommended will work fine. For your application they'll be, essentially, "bullet-proof". You can use aftermarket pushrods like those available from Comp Cams, too. Their #7954-16 is the ENGINE SET that should work best. However, use a pushrod length checking tool to make sure that stock length pushrods are what you need BEFORE you order the pushrods.

By the way, GM first validated the use of roller trunnion rocker arms for the 1996 LT4 Gen II small block engine used exclusively in Corvettes. Thereafter, they have used roller trunnion rocker arms exclusively in Gen III small block engines. They didn't do this because the old style rocker arms worked just as well.

[Duke W.]

Re: Need help choosing roller rocker arm

From the evidence I have, what typically starts valvetrain problems on either SBs or particularly BBs is some aftermarket gorilla valve spring or a camshaft with greater than OE dynamics If the cam/valvesprings are OE or OE equivalent, then the OE valvetrains have good durability.

Stick with OE or OE components and C-catergory oil and the chance of problems is minimal.

Duke