Originally Posted by CBRacerX (Post 8184815)

So I'm in the middle of rebuilding a 1980 SC engine with the stock CIS pistons (yes, small port heads). My machine shop sent me a set of Web Cam Mechanical Injection S cams instead of stock SC cams. I didn't notice this until after I installed the cams and started timing them. The engine has Crank Fire Ignition, SSI's, Sport Muffler and Weber 46's ready to bolt on.

Am I crazy to consider actually using these cams? The overlap is breathtaking, but the intake valve lift is not much different than 964 cams which are a popular upgrade with stock pistons.

I/E Lift, Duration
S Cam - .455".399", 263/235
SC Cam - .450".395", 228/218
964 Cam - .470"/.430", 238/226


See Dougherty Racing Cams Porsche 911, 930 and 964 camshaft profiles for a nice chart comparing these profiles.

Is this a valve to piston no go? I'm not going to machine the pistons - that ship has sailed with the heads bolted on