chanothemekhanik

Mainly internal like valve tappet size, intake and exhaust valve and spring I read that the stock S cams are more aggressive but my head is "supposed" to have aftermarket Web cams but no clue. Can anyone tell me what I should be looking for on stock cams? And will the chain tensioner from a S2 work on a S head? Are they any better?

V2Rocket

The 944S2 head is 99% identical to the 944S head.
All the valves, springs, tappets, camshaft chain, chain tensioner are identical and interchangeable.
All the bolts, plugs, rubber gaskets/seals and even the valve covers are identical.

The 1% difference that makes the heads themselves non-interchangeable is the design of the coolant passage on the driver side front corner, the 944S head only fits the 2.5 blocks, the 944S2 head only fits the 2.7/3.0 blocks.

They took the 944S head, adjusted the coolant passage and nothing else, and called it a 944S2 head.

The S2 intake cam has 8 degrees more duration than the S cam (224 vs 216 degrees)
The 944S exhaust camshaft is "hotter" than the S2 exhaust camshaft, so you could expect to have a minor gain in an S2 engine by installing an S exhaust cam. Both the 944S and S2 exhaust cams have 212 degrees of duration, but the S cam is "retarded" 3 degrees relative to the S2 (or the S2 is "advanced" 3 degrees relative to the S), which has potential for the S exhaust cam to free up power at higher RPM.

V2Rocket

Are you going to buy my S2 intake manifold?

Braymond

Are you suggesting that advancing the exhaust cam timing in the S will free up power in the S car or that retarding the the S2 exhaust cam timing (to match the S timing) will free up power in the S2?

V2Rocket

Putting an S exhaust cam in an S2 engine has potential to gain a little bit of high-rpm power.