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Steve@Rennsport
Steve@Rennsport is offline
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Join Date: Jul 2001
Location: Portland Oregon
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It sounds like you may need to machine a valve pocket or two to get some additional clearance for overrev protection unless you are using Ti valves.

Remember, advancing and retarding cam timing affects the powerband and this is a consideration when deciding where to set things at. If you wish to turn the engine hard, I would not advance the valve timing just to gain valve clearance.

10.5:1 is not much static compression with those cams so this will be a tradeoff.

FWIW, when we build engines like these, we have JE make the pistons to our own specs (compression and dome heights) and then we finish machine the valve pockets as necessary in each application.
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Steve Weiner
Rennsport Systems
Portland Oregon
(503) 244-0990
porsche@rennsportsystems.com
www.rennsportsystems.com
Old 03-22-2009, 04:01 PM
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