What differences are there between the above.I am told the S1 has a beefier bottom end but what other diffs are there?Can anyone tell me if the cylinder heads are interchangeable?thanks peeps

 

Engines are exactly the same m8
Just diff inlet manifolds and management no knock sensor on s1

 

pretty sure the blocks are the same, s1 head had better valves and springs, also had a 2 piece inlet manifold and they are interchangable my mates got a stg3 s1 head on a s2 block

cheers sm

 

Also the water pump, crank (oil pump drive), and oil pump were changed in 86 on all CVH engines to a different type. Late S2 blocks also were of the EFI type with readily machined locations for a crank position sensor and and a knock sensor.
Actually there are quite a few differences, but none of them make one or the other better in any way. The differences in the head and valve-gear are also very marginal.

 

yup thats right no difference in term of performance really. the S2 as an extension pipe for the turbo oil return in side the sump which doesnt seem to be there on S1.

oh and the water cooled turbo although its no difference to the actual engine