redtan

iTrader: (5)

Does the static compression ratio make a difference in the dynamic compression ratio or are they completely separate from eachother?

I ask this because I'm using a DCR calculator from I believe a guy called pianoprodigy. Using the OEM settings for my engine and the camshaft I'm running and I get 8.65 DCR...cool.

But then when I go change the headgasket thickness to say 0.040 to increase the SCR, the DCR also goes up even tho the cam specs remained exactly the same.

poltergeist 02

iTrader: (65)

yes SCR effects DCR. From what I have read 8.5 DCR is a good number to shoot for if running pump gas.

redtan

iTrader: (5)

Dang then I need to re-think my camshaft selection completely. I've been using the DCR calculator independently of the SCR info and came up with a cam that gave me around 8.6 DCR with 10.9 SCR. But with 11.5 SCR the DCR jumped to 9.1

Does that make sense that it would jump that much?

99Bluz28

iTrader: (35)

That doesn't sound right at all.
It should only be about 1/3 of a point increase in SCR, and about 1/4 point increase in DCR with that change to a .04" gasket; at least for a LS1 motor.

redtan

iTrader: (5)

It's an LS2, going from 10.9 to 11.5 with milled heads and 0.040 gaskets.

A 226/234 cam with IVC 40* comes up with 8.6 DCR on stock compression.

The same cam comes up with 9.1 DCR on 11.5 compression.

Maybe I'm just using the wrong calculator.

99Bluz28

iTrader: (35)

If you retard the cam about 4* for your current ICL it'll drop the DCR back down to about 8.65. The possible down side is that it'll shift the power band up about 300-400 rpm. Now if you want to shift the powerband up higher then that's a plus.

redtan

iTrader: (5)

Yeah that's probably what I'll end up doing, just wanted to make sure that it sounded correct before I go and change the cam specs.