My 1883cc Porsche 356 912 Blog

Chronology of a hot-rod street Porsche 356/912 1600 to 1883cc conversion based on LN Engineering's Nickies big bore kit.

Saturday, June 09, 2007

Cam choice affects driveability

I've been putting cams into engine analyzer pro to see what cams are preferable with our 1883cc big bore kit, with a focus on driveability. The first column is idle vacuum in Hg, second is the average base specific fuel consumption from idle to peak torque, and the last column is rpms at which 80% of total torque is available. All shown cams develop full HP by 6500rpm. I have ommitted the Norris 337 and 356 cams, as they aren't optimal for a street engine from the numbers I have crunched.

Stock SC/912 10.2 0.433 1500-2000
Elgin 66509 18.7 0.436 2000
Web 86 18.2 0.438 2000-2500
Elgin 7010-17 16.9 0.439 2500
Neutek SX-1 15.6 0.44 2500
Elgin 7208-19 14.3 0.444 2500-3000
Neutek SX-3 10.6 0.447 3000-3500
Web 86.5 7.7 0.463 3500
Web 86A 6.4 0.479 3500-4000

Don't get me wrong, I loved the SX-3 in my 1883, just in traffic, it wasn't the smoothest, and got poor fuel economy. In a lighter car that won't see daily driving and traffic, I wouldn't hesitate to use it again. That said, if I were to do everything again, I'd choose another cam. I am personally leaning towards the Elgin 7010-17. Obviously you trade off a few hp and rpms for a smoother engine and better bottom end, but I think something around the Elgin 7010-17 is ideal for a daily driven 1883cc.