S and Non S Engines

[Hairy Cornflake]

What is done to the standard engine to give the S 30ish more BHP?

[satman]

I think its mainly head work...and a bigger bore exhaust from cats to cans. Not sure if ECU has a different Map too...

[Whitey]

cam timing, different pistons(without the 1mm dish in the piston crown) bigger injectors, different ECU map, and bigger bore exhaust on the S cars.

Some early RR engines had steel cranks and double valve springs.

[Hairy Cornflake]

Cheers both