Posted by Chris Case [162.158.58.144] on Friday, February 24, 2017 at 21:34:15 :
In Reply to: Compression Ratio posted by Matt Wilson [162.158.69.102] on Friday, February 24, 2017 at 16:02:59 :
The earlier ones were thicker and lower compression. Latest ones were redisigned with asymmetrical chambers, you can see the difference. 16776337 is the best number.
My own head has 115 psi, 80cc chamber 1.905".
You would need to mill about .100" to make one full digit higher- 6.5 to 7.5 cr.