Answer me this!
Thread Starter
Pro
Joined: Apr 2001
Posts: 744
Likes: 13
From: Lenoir City TN
Answer me this!
I just talked with one of the Comp Cams guys about the Pro Magnum Rocker Arms about longevity in a street car with cam etc. He said that they would have to be rebuilt after about 3 years. How is it that the General puts rollers on their engines from the factory, and I assume expects them to last to 100K miles or more?
:confused:
[Modified by cshuman, 7:44 PM 2/11/2004]
:confused:
[Modified by cshuman, 7:44 PM 2/11/2004]
Drifting
Joined: Jul 2000
Posts: 1,298
Likes: 0
From: Jupiter Sunny Florida
Re: Answer me this! (cshuman)
I would think that Comp Cams rockers are made of a very light weight material that has a short life span.
The GM part would weigh more and last longer, but rob HP. :thumbs:
The GM part would weigh more and last longer, but rob HP. :thumbs:
Drifting
Joined: Aug 2000
Posts: 1,521
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From: West Islip New York
Re: Answer me this! (cshuman)
The general uses crane roller rockers. But yes, there probably is a difference in performance and materials to have them last over the long haul.
Whats really needed for the street though, that last .1 of a second or lots of trouble free miles.
Whats really needed for the street though, that last .1 of a second or lots of trouble free miles.
Thread Starter
Pro
Joined: Apr 2001
Posts: 744
Likes: 13
From: Lenoir City TN
Re: Answer me this! (1MoorTym)
So you think that maybe the crane roller aluminum rockers are better than the Comp Pro Mags. I would think not. My knowledge is that full roller rockers were never intended for the long haul. From what I can tell about the Crane aluminum rollers, which are used in the GM motors, and the Comp Pro mags is that the Comps would be a better rocker. Thats why I can't understand the longevity. If someone knows different please chime in.
Drifting
Joined: Aug 2000
Posts: 1,521
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From: West Islip New York
Re: Answer me this! (cshuman)
So you think that maybe the crane roller aluminum rockers are better than the Comp Pro Mags. I would think not.
Your original post said the the comp guys said they should be rebuild every coupe of years and you wondered why GM put rollers in theirs for the long haul. Because they are different parts thats how.
You want to build an engine using the same parts as pro-stock ?? You'd go faster but have to tear it down every couple hundred miles. Thats the trade off.
So which one is better ? Depends on what you want.
Thread Starter
Pro
Joined: Apr 2001
Posts: 744
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From: Lenoir City TN
Re: Answer me this! (1MoorTym)
I'm not trying to offend anyone. It looks to me like the Comp units are built alot better than the Crane units. Maybe Crane makes special ones for the General. Most post here indicate that they are the Gold Race units. Comp, I beleive uses very high grade components for their units and therefore I can't beleive they wouldn't be comparable to the Crane Golds. Granted a Chrome Moly or Stainless Stell body may be stronger than what is needed for a street car, but surely gives piece of mind. After that its the trunion and roller bearings, and roller tip that make the difference. Pro stock cars don't use this type of valve train anyway. I was hoping someone might know the answer to my original question.
Drifting
Joined: Aug 2000
Posts: 1,521
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From: West Islip New York
Re: Answer me this! (cshuman)
Pro stock cars don't use this type of valve train anyway.
My point has always been that not all extreme duty components do well in a every day driving situations over the long haul. Because a particular component performs extemely well over a relatively short period of time does not mean it will perform at that level for an extended period as is needed in a street car. You either get extended life at the cost of absolute peak performance, or peak performance at the expense of longevity.
No offense taken :cheers:
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Drifting
Joined: Jul 1999
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From: Baton Rouge LA
Re: Answer me this! (1MoorTym)
The issue with race parts (including most aftermarket parts of the type you are discussing) is not only the weight, but more importantly the hardness of the metal, which allows precise adjustments, light weight, and precise tolerances, but at the cost of shorter life.
The OEM parts are not lower quality at all, they just give away a bit of performance to gain a great deal of life.
It's an issue of the metalurgy, and straightforward decisions about the last drop of performance vs the need to adjust and replace perts.
I had a situation on my old Cobra (Bow Tie small block) where a valve jammed and the rocker arm wouldn't move, and the pushrod literally shattered in a thousand parts. a serious mess in the engine!
As to the Crane-Comp issue, I would certainly consider them both excellent quality.
Regards
The OEM parts are not lower quality at all, they just give away a bit of performance to gain a great deal of life.
It's an issue of the metalurgy, and straightforward decisions about the last drop of performance vs the need to adjust and replace perts.
I had a situation on my old Cobra (Bow Tie small block) where a valve jammed and the rocker arm wouldn't move, and the pushrod literally shattered in a thousand parts. a serious mess in the engine!
As to the Crane-Comp issue, I would certainly consider them both excellent quality.
Regards
Thread Starter
Pro
Joined: Apr 2001
Posts: 744
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From: Lenoir City TN
Re: Answer me this! (oldace84)
I already have a set of Proform Aluminum rollers on the car now. I broke a stud and ended up replacing all of them, thats another story. When I removed the rockers to replace the studs I noticed that they seemed to have alot more play in them than they did when they were new. I only have 2K miles on them and so I am naturally concerned. This prompted the call to Comp Cams about the Pro Mags. I have always understood that rollers were not considered perminate pieces, and Comp backed this up. I would buy the Generals Rollers if I new they would hold up better. I'll do some more research and see what I can find out about the GM units.
Thanks to all.
Thanks to all.