Kind of O/T Cylinder Heads
Turbo Mini Forums

Question for all the head modders out there (benross )

Helping a friend tune an engine which is very tricky to get parts for. We've got hold of a Cylinder head to be modified but i am wondering would there be a big gain in output without changing the cams?

Would modifying the head even be worth while?

Your veiws guys are appreciated as always.

Karl

Depends on the head/engine/brand/type I guess? Give us some more info :)

The engine is the 4g93 mitsubishi engine fitted to the Proton Satria GTi. 1.8 16V DOHC 141 BHP@6800 rpm but sings all the way to 7500.

Intake is through a single 58mm throttle body (uprated to 63mm).

Exhaust has been fitted already.

Every little helps. More important is to make sure the fuelling stays right with modifications to intake/head when running standard ECU etc.

All heads from factory are only cast. I think only Lamborghini and Rolls Royce port their heads, SO, there is a gain, but the work has to be done by somone with experience on these kinds of heads. Including valve seats etc.

agreed with tom and vegard

on the cam front genrall dont go over 270 degrees duration

Thanks guys. The work is being done by a well established company and a 'piggy back' IC has been fitted to the ECU (Unichip) so it can be mapped on a rolling road.