View single post by Judson Manning
 Posted: 11-16-2005 09:40 pm
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Judson Manning



Joined: 03-14-2005
Location: Atlanta, Georgia USA
Posts: 406
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 We engineers aren't lazy...we're just taught to make the math easy, which is much easier than taking a pipet and physically measuring the CC like we need to!  guess that means we ARE lazy????

Several things....

The stock piston is NOT zero deck height (neither is the 10.x:1 2.2 piston), however the 9.x:1 flat-top IS zero deck height, and Delta does have some zero deck height 2.2 pistons that Garry Kemp is very fond of. 

The 'math' solution gives you dish, valve reliefs and the height below deck volumes along with cc volume.  Also, the original head gasket is about 1/2 the thickness of the new Goetz(sp?) gasket.  So that thickness is also in the 'math' solution and is worth about 1/2pt in compression.

I actually remember someone posting a measured CC volume somewhere in the 40-44cc range, which is in-line with the 50-something results once you account for the gasket and deck height.

I wouldn't obsess over the math and theoretical solutions, there are plenty of us who have assembled various combinations of pistons, deck heights, cams, decked heads, etc. that can tell you what does and does not work.

Judson

Last edited on 11-17-2005 01:33 am by Judson Manning