How much CR loss from 2cc reliefs?
#1
TECH Enthusiast
Thread Starter
How much CR loss from 2cc reliefs?
needed to know how much of a drop in CR I will have from 2cc diamond pistons and how much do you shave the heads to make up for it.
Thanks for your best educated guess
Thanks for your best educated guess
#2
Launching!
Assuming you're starting at 11:1, you have a combustion volume of 70.9cc right now. Add 2cc, you have a combustion volume of 72.9cc, which yields:
(709cc + 72.9cc) / 72.9cc = 10.73 CR
If your starting CR is different, the calculation will change very slightly, but an assumption of .25 CR loss will still be close enough.
Combustion chambers lose about 1.5CC for every .010 milled off, which means that milling about .013 will recover your 2CC loss.
(709cc + 72.9cc) / 72.9cc = 10.73 CR
If your starting CR is different, the calculation will change very slightly, but an assumption of .25 CR loss will still be close enough.
Combustion chambers lose about 1.5CC for every .010 milled off, which means that milling about .013 will recover your 2CC loss.