Turbo Six Compression Ratio

[WDoug72]

Hey guys, I'm getting ready to have my E1 cylinder head sent out for a direct mount mod and installing SS valves. This head, when finished will be on my stock N/A 67 block until I have the funds to build a solid bottom end for the turbo. The question I have is what compression ratio should I be shooting for since the head will be on a N/A engine before it is boosted?

 

[WDoug72]

I should also note that I will be looking to run somewhere around 15 psi of boost when turbo-ed. It will be a daily driver in the non-winter months and would like to run it on pump gas.

 

[Does10s]

No greater than 8.5:1.

It'll be a dog while you're running N/A, but be good when turbo'd.
If you O-ring the block you can run a copper head gasket. Get a .025" thick one during the N/A phase, then switch to a .086" or thicker when you add the turbo.
Just make sure you have adjustable rocker arms or you'll probably need to get different pushrods.

Will

 

[Turbo_B]

I am running stock compression on a stock head and get detonation at 11.5psi. Spend the time (or coin) and break the sharp edges in the head and polish the rough spots out of the head.

 

[WDoug72]

Thanks guys for the replies Ill have to make sure I port the head as well.