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Carrera3.5L Carrera3.5L is offline
Doesn't want/need a 3.6L
 
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Join Date: May 2004
Posts: 1,635
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I am running .75mm on my normally aspirated motor with no problem, although I am using RSR style pistons with a mild camshaft profile so I have more than adequate piston-to-valve clearance. We strive for somewhere between .8mm-1.00mm deck height. The tighter clearance may help with detonation issues.

.7mm is getting awfully tight, just to be safe you may wish to add another .25mm shim. If you have 1.00mm worth of base gaskets already, you may also wish to trade in your combinaton of .25mm-.5mm base gaskets for a 1.0mm & .25mm shim. It may lessen the opportunity for a leak later.

If you have the time and are willing to experiment, you can build the long block, time the cams and check your piston-to-valve clearance to see if you have a problem. You may or may not get away with the tight clearance.

At least your smart and checked your deck height, you would be surprised how often this process is overlooked, even by supposed "experienced" engine builders. We sent out quite a few "replacement" Mahle pistons to shops around the country that made this error. You can't assume anything.

Ralph
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1988 Carrera w/ 3.5L Twin-Plug

2008 Cayman S (coming soon)
Old 04-09-2006, 07:17 PM
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