[66i6]

I installed my pertronix ingitor last night and was amazed at how easy it was to install. I've been a stick in the mud for years because I never thought points were that difficult to work with. If I hadn't got the ingnitor at a "too good to pass" price I would have been content to keep using the "old fart" technology.

Any way, I installed it and was amazed at how easy it was. Car seemed to run okay, but as I explained last night, my car started running way too rich after changing out my carb's jets. I blamed it on my jets at first (which should have been the same as the old ones) but then I decided to get out my engine analyzer and check things more closely. I noticed that dwell was reading 33 degrees, way off from the 26 1/2 to 28 degrees that the manual calls for.

What's up with this? Electronic or not, shouldn't the dwell ready be the same? If it were points, then this would mean the point gap was too narrow and the spark would be weakened because there's less time for the coil to build up between cylinders. Could this explain my black smoke (spark too weak)? I'm using a stock coil, but the shouldn't have anything to do with the dwell reading.

Any opinions?

 

[geegee]

33 degrees is the same as a Mallory Dual Points. Dwell is a measure of distributor cam angle. The circuit (points) to the coil are closed 33 degrees and open for 45-33=12 degrees. The spark plug fires when the circuit opens (leading edge of the change from closed to open).

Technically the longer the dwell the better the coil saturates and the more powerful the spark. Also as engine rpm increases, 33 degrees stays constant although the dwell time (time the circuit is closed) continually decreases with rpm. This means the coil does not get the same time to fully saturate as the rpm increases. Longer dwell provides for increased rpm capability. Okay, enough theory.

Your system is fine. Just reset the timing now and you're all done (note changing dwell impacts your timing so you'll want to check and reset it with a timing light).

 

[66i6]

Thanks for that detailed explaination! "Think" I got all that! ;-) I did NOT check my timing, so I'll do that ASAP. Guess it'll run even better after that.