172 or high comp williams

[Stu 16v]

Hi guys, just after some opinions/experiance if anyone can help?

got a mk1 16v that id planned a 172 conversion on and was gathering all my bits together, ive also got a complete williams cylinder head which came from my old engine that threw a rod and piston.

dilema now is do i go on with the 172 conversion or has anyone ever put a williams head on a 172 bottom end which should raise the compression as the pistons are the only difference?

has anyone run a williams head on a 172 block/pistons etc on a standard ecu?

stu

 

[BenR]

you cant.

 

[Stu 16v]

you cant what and why, would you like to expand on that please???

 

[Mark One]

The engines are quite different iirc mate.
Go for the High comp williams block if your looking for simplicity and the standard 172 engine if your looking to take the car to a NA 185ish bhp.
NA wise, you'll get more power with the 172 block. If you have a lot of cash to blow (about 4k) then you could do a full vag 20v conversion. To those who say you cannot do it on 4k - I havent done it yet, but I have roughly costed it at 3.5k

 

[stan*]

the oil ways are on the opposite sides of the engines.

better of just fitting high Cr forged pistons to the F7R, or the F4R.