rob3379

I need to know what would be a good compression or the max on pump fuel 6.0?

Thanks,
Rob

mattrem

iTrader: (7)

I have had people tell me around 10:7.1 or 10:8.1 on good pump gas,no more than 11:1.1. This is what I have been told. I have been asking the same question. I am upping the compression with my new heads on my SS.

Black02Z71

The new 6.0L LS2 has a 10.9:1 CR.

99Silver6.0

iTrader: (1)

Gawd dam is it really that high?

BigBlockChev572

iTrader: (7)

It really depends on how much timing you want to run. You could run a 13:1CP if you wanted, you would just have to adjust your timing properly for pump gas. Also, higher compression engines are more finicky as far as tuning is concerned and is harder on internals. I would say a 11:1 LQ4 with a nice cam and good tuning would be a pretty nice set-up.
Philip S.

rob3379

Does anyone know how much needs to be milled off the heads to reach 10.8 compression?

02sierraz71_5.3

iTrader: (2)

I just went through all this with trying to figure out how much I need to take of my 5.3 heads, they're are some calculators online that can figure it out.
You need to know stock combustion chamber size, deck height, bore diameter and stock comression. I might be forgetting one though
do a search for comression ratio calculator read up

After not getting any real clear results or answers I just gave my heads to the machine shop and said you figure it out this is what I want my compression at

mattrem

iTrader: (7)

I know that with the LQ9 ( flat top pistons) If you were to use 68cc heads you are about 10:8. I don't even know the c/r on the LQ4. What is it? 9 something?

elitotaco

9.4:1 I believe.

Yelo

On an LQ4 a set of ls1 heads (66.67cc chambers) will net you about 10.1, a set of LS6 heads get you about 10.6