Pulses Per Revolution (PPr) 440 engine

[Jesco]

Hi,
My shift-light need calibration (PPr) I guess it should be 4 but I'm not sure. The following settings is possible 1, 1.5, 2, 2.5, 3, 4, 5 and 6.
Anyone knows how many times the ignition fires per crankshaft revolution on a 440 engine. Must be setting 4...

Thanks!

[maxwellwedge]

Judging by all those settings - and the last one being 6 (12 cylinder) must be 4 for 8 cylinder.

[Jesco]

Yeah, we close this one. Must be setting 4.
The shift-light dont work thats my problem. It starts (have power) but dont show any rpm.
In my other car who have MSD 6al it worked but in the white car who have the mallory 6al it dont. The sunpro gauge (connected to same trigger wire) works in my white. Something fishy with the signal. Dont think I like mallory ignition boxes...

[Troy]

If you think about it, the crank spins 2 revolutions for each cam revolution. This is because each piston needs to come up twice per cycle - once for combustion and once to expel the exhaust. Since all eight cylinders fire on each revolution of the cam, half the cylinders fire on each revolution of the crank. The number is 4.

Troy