how many psi should you see on a compression test when set up at 10-1 in a 95" s&s 570

 

The Big Boyz site has a calculator for determining that. http://www.bigboyzcycles.com/TwinCamComp.htm With the information you have given, assumptions must be made that you have stock heads, a stock head gasket and 0 deck height. According to the numbers I put in there, you should have 189.1 psi. @ 200 feet above sea level (not knowing where you live). That could change slightly depending on where you live. I adjusted your piston dome volume to 8.1 cc's to obtain the 10/1 static CR. Be forewarned, don't run that number to the bank as I am no expert, far from it. Somebody else will chime in here eventually, there are plenty of helpful experts roaming in this forum. I'm just curious whether I ran the numbers correctly and someone else confirms. After checking bigboyz site again, that ccp could change quite a bit depending on your altitude, 2000 feet above sea level it drops to 179.4. In Denver, it would be about 163.

 

How do you know static is 10:1?

 

dan baisley set the heads up for my combo im gettin 180psi @500 ft above sea level does that sound about right