Hi all

I hope to soon have a car (circa 73 - 75) with a 440 engine. I know this engine will have a compression ratio of 8.2:1.

1) What should be done to raise the compression ratio to around 10.5:1? I would not want to skim the heads or the deck.
2) What info do I need to have about the engine before I can set about buying parts?

TIA
mopwit

 

As explained previously The only other way is to re bore the engine and replace the pistons

 

There are only 3 ways to raise compression

mill the heads

mill the deck

change the pistons

or various combinations of the above

 

mopwit -

What the guys said, but think twice before you do any of that.

The easiest route would be new pistons, but make sure you have valve clearance. Milling the block and or heads will leave you with manifold alignment and push rod length issues which will need to be addressed. (Not impossible, but annoying.)

When gas octane went down in the 80's, there where a number of articles in mags like Hot Rod, Car Craft, etc about making low (8:1) compression engines perform.

If you're not building a race car, stay with the lower compression ratio might save you a few bucks on gas.

Archer

 

Run the same pistons as me. Kieth Black 237 pistons have 5cc valve notches and mill the deck .010 and the heads .010 and you will be right in the ballpark. With 80cc combustion chambers on the heads you will be at 10.6 to 1.