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Old 11-05-2011, 01:15 PM   #87
69Cobra
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Location: California, Ky
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Default Re: Roller Rockers in Stock

Quote:
Originally Posted by Alan Roehrich View Post
With CNC machinery, you can make an aluminum roller rocker that looks just like any other aluminum roller rocker, including an "approved" rocker, modify the geometry, mark it and anodize it to look like the approved part, and the only way to find it is not the approved part is with a fixture made to check that specific approved part.

With CNC equipment as common as it now is, it is not even expensive to make the cheated up rockers. The rest of the parts are commonly available.

What do you think the chances of NHRA making or buying checking fixtures for 2 dozen different rocker arms and taking them to every event is? Or the idea that they're going to procure 7 copies of each approved part and haul them around to every race?

The idea that "you can keep your stock style rocker if you want to" doesn't hold a drop of water, not if you want to remain competitive. If the roller rocker raises the operating range of your competition, you have to run that RPM just like he does if you don't want to get beat.

People going fast are not just going to bolt on a set of roller rocker arms and call it a day. This is not "one part, that solves breakage for some people". Rocker arms are one part of a complete valvetrain package. Change rocker arms, and you change camshafts and other parts to go along with the rockers, unless you want to get left behind.

The fast guys will completely reevaluate their cams, springs, valve job, valves, and pushrods, in order to take advantage of the change. So instead of changing a set of rockers at the cost of $300 or so, you're now looking at a new cam, $200 and up, a new valve job that may cost you $1000, new valves that could cost $500, and new springs for $300. Your new roller rockers just went from $300 to at least $2300 if you want to stay competitive.

Yes, roller rocker arms are going to save you money. So long as you just change rocker arms, and you don't care about making the rest of the valvetrain work with them to remain competitive.
Now I'm just trying to learn here. If you just change your stock ratio rocker to a roller rocker of the same ratio why would you want to change cams, valves and valve jobs? I would think the springs should go your way. With the roller rockers being lighter you should gain more controlable spring pressure for the valve, right? Now if you change to a faster ratio rocker then I can see having to change the over all cam lift because your faster ratio rocker just added lift at the valve. But I would think that is not the intent here.
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