What is a good compression?

The engine has to be in pristine condition before adding a supercharger. Next up is a leak down test to determine if valves are leaking or perhaps, less likely, broken rings.

 

Give it an Italian tune up and retest. Don’t let car temp drop between readings. Good compression is consistent.

 

I wouldn't be exited about putting a blower on a 2 valve injected car with the poorly designed ring package Ferrari used in them no matter the compression results. It was more about poor oil control than compression. Put a blower on it and you will likely just have an 8 cylinder oil pump.

 

Brian - Thank you for your expertise and experience.

If I may, did Ferrari change the ring package for some reason during the transition from carbs to injection, circa 1980?

Curious as to your thoughts as to the reason why the 308's 2-valve injection engine run has since earned the bad rap as oil burners, compared to the earlier and the later iterations.

Thanks and Regards - DM

 

Since earned? Where have you been. That reputation was carved in stone since 6 months after they came out.

Simple. Its called an intake plenum.

 

In any case, adding a supercharger or a turbo charger to any engine not so designed is asking for trouble. Factory forced induction engines use much stronger internals, block and often overlooked is the cam profile of forced induction vs naturally aspirated. Further, its likely to cost about the same amount as it will depreciate the cars value and possibly make it sale proof. The reality is, if you want a faster ferrari, you buy one.

 

While I agree with most of the rest the Ferrari F40 had no stronger a block, crank, connecting rods or pistons than a standard 308.

 

Do the dry and wet test and leak down test to determine if you have any issues