260Z Dyno Results

[Ron Earp]

Ok, found that data on the Z cams. I'll just put the important specs here, got them all but most isn't that important for comparison, just for checking one out.

The A and C cams are very similar.

Both are ground on 109 degree lobe centers and will deliver similar power bands. The C cam has 10 more degrees of duration over the A cam and in theory could result in a bit better cylinder filling raising VE a bit. So the advantage here would go the the C cam, slightly.

The lift on both cams are identical on exhaust at 10.4mm, but on the intake the A cam has 0.5mm more lift at 10.5mm versus 10.mm for the C. Advantage here would go to the A cam, slightly.

The 260Z head has a 1mm larger exhaust valve over the 240Z, so slight advantage to the 260Z head. However, the 260Z has about 0.5 points lower on compression than the 240Z, advantage 240Z.

Looks like a big wash to me. I'm told from Riley and others the C cam was a good cheat back in the day for 240Z drivers, but it looks like it wouldn't be much of a cheat.

As for the 280Z there are a bunch of cams - A, F, B, J, M, and E. The best one out of the bunch seems to be the A which exactly mimics the A for the 240Z.

Curiously enough, out of all the cams the 260Z C cam has the longest duration.

Ron