New Petronics Ignitors

[Dale M.]

Re: New Petronics Ignitors

Ken, I understand that HEI distributors put out 45,000 volts. They do not melt the spark plugs or their wires (which are upgraded from our old cars). But this does mean that you can increase the gap on the spark plug and produce more spark to better ignite the fuel in the cylinder. The version 3, is a multi-spark, which means that you get 2 sparks for firing the cylinder. This is used in race cars, not sure how important this is in a street car. But I would it would help burn all of the fuel in the cylinder each time it fires.

[Michael W.]

Re: New Petronics Ignitors

Ken, I understand that HEI distributors put out 45,000 volts. They do not melt the spark plugs or their wires (which are upgraded from our old cars).

Not quite- an HEI unit has the capacity to discharge at 45Kv, but does not actually do so under normal conditions. The discharge voltage is (amongst other factors) determined by the plug gap. As noted above a normal gap takes only 12Kv to jump. Increasing the plug gap will increase the voltage required to do so. Early HEI cars initially used a gap of .060" or larger and soon ran into the burned wires and caps noted by Ken above. GM backed off the gap to .045" accordingly.

Note that the introduction of HEI on Corvettes in 1975 had nothing to do with increased performance and everything to do with having a maintenance-free system firing a miserably lean mixture.

[Roger W.]

Re: New Petronics Ignitors

Dale, I just received my new copy of summit racing and noted that MSD has a new digital module that fits in side the dist. and has a single wire, its digital and has some neat features, like mutliple sparks on start, for easier start, it moniter timing and dwell control through the module. and does use the cam on the Dist. not a magnetic plate. I though that its was neat. and that I may try it in the my 63 , I do have the older petronix in my 72 but its has the 2 wires.which I recently remove for judging reason, they work well. But you'll get alittle more from the MSD set up.

I saw that MSD Ignition in one of my magazines. It looks pretty good. It would be interesting to hear from someone who has tried one.