Compression ratio math?
 

I've just measured my motor. And would like to see what compression ratio others come up with?
Here are my specs.
Bore 3.480
Stroke 3.976
Flat of piston is .010 out of the bore
Head volume 49 cc
Head gasket thickness .077
Head gasket bore 3.50
Volume of cylinder with piston .355 down the bore is 47 cc
I believe that will give me a dome volume of 8.33 cc's
Head gasket volume is 12.14 cc's
Cylinder volume is 619.7 cc's

Re: Compression ratio math?
 

Sorry meant to post this in the tech section.
I've used some of the online calculators and I get some quite different answers.
Numbers vary from 11.7 to 1 to 13.0 to 1

Re: Compression ratio math?
 

Art. My compression ratio program useing your info. Say's it's 13.1:1 normally aspirated at sea level. I also get the same cylinder volume as you do 619.7 cc's.....hope this helps.....norm

Re: Compression ratio math?
 

Using the compression ratio calculator on my copy of Larry Meaux's PipeMax software, I get 13:1.

Re: Compression ratio math?
 

Google compression ratio calculator. A nice site comes up with a number of different tools.

Re: Compression ratio math?
 

Art, you should buy Pipemax. Very usefull.