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Re: A Comment on Points and Condensor
Michael;
The Pertronix II unit, or any reliable electronic ignition, provides more precise timing and dwell angle for optimum spark voltage to the plugs whether at idle or at redline. Ignition points, by their mechanical nature, begin to degrade as soon as they are set and you run with them. If they are set incorrectly or are degradated, they cause the timing to actually become retarded. With the Pertronix II unit, the dwell angle changes constantly for best performance. It allows me to use a full 12 volt input to a 0.6 ohm coil for better starting hot or cold, and I can still use OE spark plug wires and ignition shielding in order to take advantage of a great aftermarket sound system.
But the bottom line for the plugs is, when you are getting more precise timing, you're getting more efficient combustion which (in effect) keeps the plugs clean and free from build up of carbon (unburned) deposits. It's that build up that fouls the plugs, and with a high compression engine, if you foul the plugs they are usually dead. There is nothing you can do to clean them while still in the engine or out. You can't just go out and "blow the carbon out". They may heal a little and give you 5000 RPM before they break, but they will never give you redline again. You pull them, scrap them and replace them. So has been my experience.
Stu FoxComment
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Re: A Comment on Points and Condensor
Spark energy is a function of primary current and coil design. I think the first generation Pertronix used the OE coil and ballast, so there was no change in spark energy. Perhaps the second generation allows 12v to the coil, but this will probably eventually fry the OE coil.
After the TI on my car stranded me a the second time in 40K miles I reinstalled the OE single point distributor, which I had blueprinted. Much to my joy, the engine ran the same.
The TI (and HEI) has about double the per spark ignition energy as the single point, so the TI/HEI can blow a spark through plug fouling that the single point won't, but with the blueprinted distributor and AC 45s "plug fouling" was no longer an issue.
The HEI in my Cosworth Vega also stranded my twice, but the first time I was able to jury rig it to get home. I now carry a spare HEI distributor and a 9/16" wrench in the spare tire compartment if it ever happens again.
DukeComment
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Re: A Comment on Points and Condensor
Duke;
The Pertronix II literature recommends NOT using an OE coil. I use there "Flamethrower" 45,000 volt 0.6 ohm coil. They also claim their original Pertronix units lasted up to 25 years w/o failure.
You may recall our discussion of some time back I mentioned I used a ball bearing plate in my distributor, but could not recall the name. Well, I found the box and instructions for it. It was made by an outfit called "Dyna-Flyte" and is their Model #956. I had to modify my Pertronix II unit that mounts on the plate as it would sit right on top of one (of three) rivet heads which would have prevented it from mounting flat to the plate. I merely lined up the spot and drilled a hole in it large enough to clear.
Regarding your failing HEI, I recall back in the 80's, we used to use a "parking lot fix" as it seemed that's where they would always fail in the EMD parking lot. You take off your work boot and rap it on the top a few times. Seriously, that would usually get you started, then you went home and pulled it apart, cleaned the module and it's contacts, then stuck it back in with lots of that dielectric grease. That would hold it until the next year at least.
Stu FoxComment
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Re: A Comment on Points and Condensor
So your theory is that the points are allowed to deteriorate sufficiently that the timing is thrown off, and/or the distributor shaft and bushings becomes worn to the point that the timing jumps erratically. Without one or the other factor there's no reason to believe that this device would improve any measurable parameter.
I believe standard maintenance practices would address both concerns without resorting to an aftermarket device- especially if the conversion now becomes obvious by using a different coil.
Their 25 year claim didn't do me much good when I was stranded on a Sunday afternoon in the middle of nowhere.
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Re: A Comment on Points and Condensor
Actually the CV HEI failed three times, and the four-cylinder second order vertical shaking force (15g/233 Hz at 7K revs) is probably a big factor. A V-8 is a much less severe vibration enviroment.
First failure was the lead wires coming out of the pickup coil. That was during a track event at Riverside circa 1985.
A few years later one of the two wires on the primary harness (to the external coil on four cylinder engines) failed where it exits the distributor, but I was able to jury rig it to make the few miles home.
Third time was in a friend's driveway, not too far away. It was late night, so he drove me home and picked me up the next morning. Armed with my service manual and multimeter I went thorugh the HEI troubleshooting procedure. All tests were fine up to the point where it said "test module in module tester". Of course I didn't have a module tester, but I did have a new spare module, which I installed, and it fired right up.
It only took five minutes to test and five minutes to install the new module. I was fortunate that it didn't fail on the freeway.
DukeComment
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Re: A Comment on Points and Condensor
Michael;
I wish I could take credit for the "theory" as you call it, but I'm afraid there were many automotive power plant engineers that advanced the theory into practical reality long before I adopted it. I have no axe to grind or hidden agenda here. I'm only reporting what worked for me, and it bothers me not whether anyone else agrees or believes it. Yes, I use an aftermarket 45,000 volt coil which is hidden by the shielding to the casual observer. For the purists sake, what's the difference between that and a Top Flite car with a hidden Comp Cam camshaft with roller lifters, or aftermarket pistons and rods, to say nothing about reworked heads with hardened valve seats.
I've owned my 63 since new, and it has been a love affair of over 45 years. It looks as good as many Top Flite cars and is more original than most. It has been through good times and bad like hitting a 215 lb deer and driving under the rear end of a truck when it's J65 brakes were still cold. It's had it's antenna broken off and convertible top cut by vandals, and it has lived to take top honors at many car shows as the many trophys I have will attest to. The engine has never been apart, nor the clutch or transmission during it's logged 44.5k miles.
I have had open heart surgery and it provides me with the best medicine of all when I take it out on a Sunday morning and run it up to the red line through the gears. And, thanks to it's electronic ignition, it doesn't miss a beat.
That's my testimonial, and I approved this message.
Stu FoxComment
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Re: A Comment on Points and Condensor
Paul -
I really think you should wax your '74 so the paint shines more
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I noted the air deflector on top of the windshield frame - is it effective in reducing buffeting?Comment
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Re: A Comment on Points and Condensor
My interest in this subject is an attempt to understand the on-going fascination with these units by the average consumer.
The majority of the advertised/perceived/mythical benefits of these devices compared to the real/documented/tangible benefits so far do not match. The fact that one manufacturer has had a less than stellar reliability record adds an interesting twist.
Having had a 30 year career (so far) in the engine design, manufacturing and reliability tracking field has fueled this interest- particularly since the device adds a sudden and critical failure mode that does not exist in the standard points and condenser config. Such a design fault would not be permitted in the aviation field I can assure you.
The statement that 'the plugs last longer' was one that I had not heard mentioned before. Given that the device is simply an electronic switch (vs. mechanical) I was curious as to the the explanation and proof behind it.
Thanks anyway.
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