Hey guys,

I'm getting ready to slap on a set of L92 heads on my 05 C6. Haven't gotten my cam yet but it will be something around a 224/228 with no more than .600 lift. The car is a daily driver so reliability is a must.

My question is:
How much compression can I run on pump gas (91 octane)? The higher the better so i can retain as much bottom end power.

I know the pistons will need to be fly cut & heads will need to be milled.

Thanks guys

 

We are getting away w/ 12.5:1 on the ls7s using 93 oct. and 23x or 24x cams. I run 11.9:1 myself on stroked street LS7, 22* timing and 93 octane. No issues....

 

With a 224 / 228 cam you may not need to flycut the pistons. You may also just be able to use cometic thinner head gaskets and get the compression bump you need. 11.5 - 11.75 to 1 should still be fine on pump gas.

 

I would be worried about PTV clearance before I would be worried about compression. Fly cutting may be in order depending on the cam.

 

Ya i'm almost positive I'm going to have to flycut the pistons.

I think i'll go with 11.5:1 or 11.75:1 just because i only have access to 91 octane here in SoCali.

Thanks for your help guys.

 

Im running forged pistons with reliefs, but milled heads .055", and it has right at 13:1 CR, runs on 93, with 244/248 cam. L92's love compression

 

So what do these heads like better?

smaller cams like a 224/228 or something bigger like a 232/236?
I want something that can keep a good amount of bottom end torque but screams up top. This will also be going into a daily driver so i don't want any surging or shaking.

LG motorsports is recommending me to go with their G6X3 Executive cam.

Thanks for all your opinions guys.

 

These heads love timing - more so than the cathedral port heads. Give up some CR and add timing to make HP. They will still produce great low/mid power.

Just my $.02

Been there - done that.

 

So would 11.0:1 be good enough to add more timing?

 

Yup! You should be able to get around 30 degrees of lead at 11:1

 

Timing does seem to help a lot. Keep the IVC a bit later and you'll be able to run a bit more timing and pull to a 7k shift. Maybe something like a 228/228 114 114

Good luck

EDIT: I have not evaluated PTV for the suggested cam. got to be carefull if you do not end up fly cutting.