C3 - 1972 LS5 distributor question

[Randall K.]

Hello Distributor Experts - found some time today to get into the garage and check out my misbehaving ignition. I found something that puzzles me.

I can rotate the distributor shaft by hand somewhere around 10-15 degrees rotation (almost half of one of the cam flats). Is this normal??

Thanks!

[Duke W.]

Re: C3 - 1972 LS5 distributor question

You were not rotating the shaft, which is fixed to the camshaft via a pair of bevel gears. You were rotating the cam assembly through the centrifugal spark advance angle. You can do the same thing by pulling the ends of the weights out to their limit of travel. When you do this the cam rotates CCW, which advances the spark timing.

Duke

[Randall K.]

Re: C3 - 1972 LS5 distributor question

Of course... apparently I've been inhaling too much unburned gas!