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Old 07-01-2016, 07:54 AM   #153
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lookforjoe's Avatar
Join Date: May 2008
Location: Rockland County, NY

Originally Posted by bobxyz View Post
Try using this calculator:

It's pretty easy and accounts for all the bigger items - you'll need to subtract your .65mm piston popup from the gasket thickness and enter it in the gasket thickness box. For the ring land clearance, which I've never seen before, you can put your calculated volume in the piston dome box (-.925cc). I'm not sure why the valve flycut gets added in at all - isn't it already accounted for in the measured chamber volume?

[BTW: the value of pi in the equations you got from the other site is off a bit; should be 3.14159.]
Thanks for the suggestion - using the calc this is what I get:

The flycut in the piston is not included in chamber volume using the other method. I added it to chamber cc.

10.1:1 is also good My goal was to get it down into the 10.1 - 10.3 range.

My XR July2013 - 446AWHP @ 8K rpm
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