I would step up to shaft mount rockers. You will pick up around 10 hp. eliminates play from side to side you will get a tad more lift.

In and of itself, simply switching to shaft mount rocker arms over stud mounted rocker arms will neither garantee more lift at the valve nor will it garantee more horsepower.

LO

LO...With all due respect.....I disagree with you...The rocker MUST ride in the middle of the valve tip...

It has been my observation that this is a common misconception, that the roller "MUST" ride in the middle of the valve. To most people it seems to make better sense intuitively that the roller tip must be centered on the tip of the valve.  That is not the case.  But....you first   : Why do you think the roller "MUST" ride on the middle of the valve tip?

Please explain.."It is ..ballpark"

Truly sorry, I type fast and move from forum-to-forum, sometimes with an inadequate proof-read....I'll try to re-write the statement in a more easily readable context:

Using the "roller-tip-in-the-middle-of-the-valve" technique during valve train setup is not a garantee that correct valve train geometry will be established (but most rocker arm manufacturers design a body for a specific valve train and so practicing that method can usually get geometry in the ballpark).  

By the way, being "in the ballpark" can be good enough for most of the mild performance builds out there, but maybe not acceptable for the most serious engine builders.

LO

i had another one fail....didnt break like the one pictured, but had the cup wear like the other.

i will be putting a new set of rockers on order today. in the mean time....what do i need to do to check my geometry so i know its not the setup, but cheap parts and im not going to run into this problem again on a more expensive set of rockers.

i had another one fail....didnt break like the one pictured, but had the cup wear like the other.

i will be putting a new set of rockers on order today. in the mean time....what do i need to do to check my geometry so i know its not the setup, but cheap parts and im not going to run into this problem again on a more expensive set of rockers.

B, no rocker is that "cheap" that it comes apart in a couple hours. You have another problem. Check the stuff Glen outlined and you'll prolly find some bind somewhere

thats the plan...i will be going through the valve train when i drop on the new rockers...checking the things glen outlined. better safe then sorry...dont want to junk another set of rockers.

what do you guys think about the comp cams ultra golds? http://www.summitracing.com/parts/CCA-19021-16/

Are these the same rockers that have been on this motor for X number of years? Or were they part of the new valve train?

part of the new valve train

In and of itself, simply switching to shaft mount rocker arms over stud mounted rocker arms will neither garantee more lift at the valve nor will it garantee more horsepower.

LO

 Sorry bud but your wrong. Here's the proof.

HRiderTH: It's certainly possible that geometry which is really out of whack can destroy rocker arms (interference issues, extreme over-arcing/under-arcing, etc) but you have to be a zero-experience engine buidling enthusiast with zero understanding of valve train geometry...and I refuse to believe that Brad could be that far off...just can't be!    Also, I hate to say this but ProComp rockers have indeed been known to disintegrate early in life.  I am aware of multiple experiences with the ProComp rocker arms that are very similar to what is pictured here.

Over the years I have watched offshore manufactured high performance engine products improve with time, improved finish, imrpoved fit, improved strength, etc. At the time of this writing, ProComp specifically is still low on that ladder and the general consensus about Pro Comp among the circles in which I associate is: if is has moving parts (waterpumps, rocker arms, etc), don't even think about using it; but if is is solid (main caps, rods, etc), you may use but thoroghly measure and inspect the component(s) and use well within its intended means.

Brad: Follow GT Jets advice. Also, take some time to first read up on valve train geometry and also feel free to give me a call of you have questions during evaluation.  There are several theories as to what is "correct" valve train geometry. The theory on valve train geometry that makes the most sense to me happens to be the only one that ever received a patent and that is Mid-Lift valve train geometry, which was conceptualized and campaigned by my personal friend and mentor, Jim Miller.

I have never used the Comp Golds but I have heard good things about them. Also, CompCams offers a lifetime warranty with them (you had better ask if that includes racing applications, as few engine parts are warranted under racing conditions).  If you don't go with the Comp Cams rockers, then I suggest the Scorpion BBF 1.73 ratio stud rockers.

LO

 Sorry bud but your wrong. Here's the proof.

I read the attachment/advertisement. Twice.  I had to read it twice because, 1) I didn't see anything written in the advertisement about horsepower gains that applied specifically to shaft rockers in general, and, 2) the claims that I did see about hp gains were not rocker shaft specific but were actually design related...design specs which can be applied to any roller rocker, be it a shaft system, a stand system, or even a stud system.

In my mind, the bigger joke about the attachment you posted is this: I think that the Crane advertisement is discussing in a round-about way that they have found a way to make a "variable ratio rocker arm" which is not entirely true. (ALL rocker arms have some variation in ratio as they travel through their radial sweep.) What I think Crane realized/admitted is that all these years they have been making their rockers arm with a geometric design flaw (as viewed by at least one other manufacturer that I know of), and instead of admitting their mistake they "spun" this "new feature" (relocating the pushrod cup) as a rocker arm "improvement" or "enhancement" rather than openly admitting their oversight and saying that they have now corrected it.  And guess what? In backing up what they now feel is the better way, they touch on the Mid-Lift geometry principle in their explanation, which is the very patented geometry principle that suggested they had a flaw in their rocker arm geometry design in the first place. What a joke this is. And you not only bought it but you also misinterpreted it as shaft rocker specific.  

LO

Hello Lakes..... if ya want my opinion ...I will give ya it...

This process is essential to prevent v/stem wear among other issues as we both know.

Your turn Boss

And there-in lies the most common misconception about why the roller tip must be kept around the middle of the valve....because "the valve guides will prematurely wear if the roller tip is on the outer (or inner) edge."

Not necessarily true. But please let me elaborate. Technically speaking--if you want to split hairs (and I mean really fine hairs)--this belief indeed makes sense. But it is more true in a shoe-style rocker tip/pad and 90% less true in a roller-tipped rocker. Here's why:

The big misunderstanding about roller tips is that everyone thinks the roller tip is there to reduce friction. This is not why the roller tip is there. The trunnion bears the most load from the spring pressures (because of the leverage factored in from the rocker body extending to the valve tip) and so the trunnion needle bearings reduce all that friction, not the roller tip.  In fact, when one considers that a roller tip "sweeps" accross the tip of a valve stem perhaps just 0.060", can we really say that it is rolling?  In reality, as the engine runs the roller tip is "dancing" on the valve stem more than it is rolling....sometimes coming completely off the tip of the stem (as with solid-lifter-engined combinations that have valve lash clearance).

So what is the purpose of the roller tip?  The purpose of the roller tip is to provide a second pivot point in the valve train so that as the rocker arm goes through its radial sweep the forces directed toward the valve are kept in-line with the valve stem so that it does not push the stem sideways and better transmits the camshaft's linear information throughout the rocker arm's radial sweep. Here is an example of what I am talking about (paraphrased from Jim Miller):

"People think the roller is for reducing drag. It is not. It is to provide a second pivot point that is constantly aiming the load forces at the valve tip's contact surface so as to be directly in line with the valve stem axis. A simple parallel you can do is the following:

Hang a weight from a piece of string about 18 or 24 inches long.
Imagine your arm is the PIVOT LENGTH dimension of a rocker arm, pivoting at the shoulder.
Holding the end of the string with your fingers out in front of you, raise your arm upward about 1 foot above horizontal, then lower it down about 1 foot below horizontal, and watch the weight stay suspended roughly in the same place.

What is important though, is the STRING.
The string represents LOADS, and it also represents the DIAMETER of our ROLLER. IT is always in straight line with what our imaginary valve (that our weight is pushing against) as the rocker travels though its radial sweep. Without it, these loads take glancing angles from OVER-ARCING to UNDER-ARCING, as if your HAND was directly where the valve tip was at (without the weight/string). You'll notice in this example what your hand holding the string was doing."

One recent example: We recently disassembled a 557 CI racing engine (built by another shop) that had almost 0.800" lift and crazy valve spring pressures. It also had valves that were 0.250" long (which were all wrong/too long in my book) and because of the canted valve layout those long valves put the valve's tip closer to the rocker stud and thusly the roller tip on the very outer edge of the super long canted valve stems. This engine was run this way--with its big spring pressures and 7600 rpm redline--for 8 years. But the valve train geometry was pretty close.  And upon disassembly for a rebuild after 8 years of racing, we did not find any discernable guide wear beyond spec and/or that dictated so much as servicing the guides.  I fully admit that the location of that roller tip looked downright scary, that I didn't like it, and that I felt the roller's location went way beyond the allowable "boundaries" of where I feel a roller tip should be positioned, but thanks to reasonable valve train geometry combined with the rollerized rocker arm tip, the guides were just fine.

Whew, that's enough for me tonight....  
  
LO

the application here in discussion is a pretty much stock bottom end hardin marine bbc with 990 heads that were gone through and valves/springs setup for the cam that came with it (solid flat cam). i set the valve lash to the cam card (.021) and the boat doesnt go over 4k @ 62mph

this isnt a full blown race application....its just a lake boat motor in a day cruiser.