I need help understanding where the 10.1:1 compression ratio comes from with the following information: 3.898" Bore , 3.622" Stroke, 66.67cc chamber volume. I'm using the equation: CR = ((pi/4)*bore^2*stroke)/Vc + 1 .... where Vc = chamber volume. Anyway the CR I calculate is = ((pi/4)*3.898^2*3.622)/4.0685 + 1 = 11.624. Is the 10.1:1 come from 'Dynamic Compression Ratio' that has to do with the delayed closing of the intake valve? HELP ME!! I'm Confused!! Thanks in advance!

 

No it is SCR. try this calculator>>>> http://www.csgnetwork.com/compcalc.html HG thickness is .054 and deck clearance is +.007.

This is in the ballpark and gives me 10.109950593436714 for a stock LS1.

 

THANKS A BUNCH!! Actually after I wrote that big spill, I back calculated using 10.1 CR and calculated for a head gasket and it came up with 0.057" which makes sense. Thanks for the link and the info. I may have to make a new thread, but does anyone know the stock CAM advance? The info I found only specifies duration and LCA, but no info on if it's advanced or 'straight up'.

 

Enter Piston Dome Volume In CCs Negative For Dished Pistons (Use '-') What is it for a stock LS1 piston?

 

Stock LS1 pistons are flat tops with no valve reliefs.

 

deck clearence is -.007. they are out of the hole. not in.

 

it shows that the 63cc patriot stage 3 5.3l heads give 10.5:1 compression, i thought it was 11:1 compression??

 

Off the top of my head a 63cc chamber will give approximately 10.7-1 with a GM MLS. gasket. That is my setup right now. A stock 64cc 243 head will yield 10.5-1

 

Thanks!! Good information..