saywhenn94

If i'm not mistaken the LS2 head is the same as the LS6?? I'm going to buy a set of Dart Pro 1 225's...which have a 62cc combustion chamber as compared to 67cc for the LS2. If the LS2 has 10.9 cr and I use the Darts with a stock gasket where would that put my CR? Could I still run 93 octane?

Thanks,
Rich

405HP_Z06

iTrader: (11)

The LS6/2 heads have a 65cc combustion chamber.

Everything else the same, you will get an 11.29 compression ratio with the 62cc Darts.

HEMIETR

iTrader: (2)

LS2 has a 64cc combustion chamber. To know your true CR you will need to know piston to deck clearence. Mine was .005 out of the hole. The majority of people go with a .040 gasket to avhieve a tighter quench.

405HP_Z06

iTrader: (11)

Factory spec for the 243 is 64.43cc but if you measure, on average, they are closer to 65cc. I set the piston .005 out of the hole to get the 11.29, which is close to average. Of course, measuring actual would be the most accurate.

I guess it depends on if you want to know theoretical or actual compression ratio.

saywhenn94

So then 93 octane is still doable? When the time comes i'll measure piston to deck at all 4 corners to see exactly where i'm at. So I should come in around 11.3:1 with a stock gasket?

Thanks,
Rich

405HP_Z06

iTrader: (11)

Yes, 93 should work fine.

See attached file for CR calculation.

saywhenn94

Thanks..I appreciate that.

Rich