electronic ignition

Originally posted by marco
Hello all,

Just another tip for setting the ignition timing, either electronic or conventional:

I use a vacuum gauge instead.
After setting the idling rpm about correctly, connect the vacuum gauge to the inlet manifold.
Now turn the distributor so that the vacuum gauge gives its highest reading.

Quite right Marco, but you need to be sure of your engine and ignition timing data first or there are some nasty surprises for the unwary!!

There may be more occasions but here's two where you could be very wrong setting the timing dynamically by vacuum reading:

The Morris-Commercial OH type 6 cyl engine in mil service has a TDC pointer on the flywheel and a separate timing pointer, the timing is 3/8" of flywheel circumference after TDC static.

The RR B Range engines are also timed after TDC static too (0º - 2º) and in both instances idle occurs with the engine still quite retarded and setting these by vacuum reading would result in gross over-advance in the running range when centrifugal advance occurs a little over idle speed.

We deduce both these engines have the distributor advance curve so arranged in order that hand cranking can be done without any danger of a kick-back.

R.