Thoughts on Solid-State Ignition System for my 36

I would not even think about it.

Why is that Gene?

150 miles from home and it quits, what are you going to do?

That is what if it failed. What if you say break a drive shaft at 150 miles from home, what do you do then? I know it would be easier to carry an extra set of points and condenser it is just that it “might fail” is not a reason not to do something. I would like to know if there is a real advantage or disadvantage to installing solid state ignition. I have had an issue with my distributor for several years and have tried everything recommended to me on the chat forum to no avail. I have just gotten to this point where I am ready to try something else.

I have never installed a solid state ignition conversion on a car that came with points. Based on numerous personal anecdotes as well as posts in multiple forums there are more opportunities for failure than I want to chance. Google “Pertronix Failures”.

You might not remember when the major auto manufacturers started using electronic ignition. Failures were not uncommon. The failures were often attributed to heat. I remember that I carried a spare module in my ‘78 Pontiac. We would have to pour cold water on the ignition module in my sister’s ‘78 Mustang.

My other observation is that despite what we like to think, most aftermarket parts manufacturers do not have the testing capabilities and quality control that major manufacturers and OE suppliers have. For example, the holy grail for OE suppliers is a 6 sigma failure rate. That means 3.4 failures per one million parts. 3 sigma (which would be typical for an aftermarket supplier) means that about 94% of the parts do not fail.

Do you want to be in the 6%?

What is the trouble you are having with the original set-up? Maybe it can be remedied.

Thank you. I have posed the problem with the car before when I was looking for a reason for it to start missing and even a occasional backfire, when accelerating while driving at 60MPH. The same when climbing mountains, (not hills) at 60 to 65. Otherwise, the Black Bird runs great. I went through all the suggestions as to what it might be but got down to the distributor, the only thing left to go wrong. I replaced points, condenser and coil. Still the same. Everything short of a rebuild, which is above my skill level. A mechanic who is very knowledgeable and came highly recommended (and also lives 100 miles away) has it in his shop and he confirmed it was the distributor. He could either rebuild it or replace it with solid state, which he is a firm believer in. This is why I wanted some input on the solid state. I have the same hesitation about putting new technology in an old vehicle, unless you are taking its soul anyway for a street rod.

The solid state conversion is only replacing one portion of the ignition system. It replaces the points and condenser.

If the problem is the points “bouncing” at the higher engine speed the conversion might help that. However, if point bounce is the problem you should experience the miss at the same higher engine speeds in the lower gears.

Have you replaced the distributor cap, rotor, wires, and spark plugs? Your description of a high speed high load miss sure point to those components.

If the problem is wear in the distributor drive gear as well as the shaft and bushings the electronic conversion might not fix things. Wear in the gears means that the backlash will alter timing as the load changes on the distributor drive.

If the bushings and shaft are worn that will allow the lobed cam to move. That changes the point gap and timing. Most likely the trigger wheel for the electronic conversion fits on the shaft. If it is an inductor type trigger the change in distance could change the timing.

I did the distributor cap, rotor, wires, and spark plugs but to no advantage. The car is still in his shop and I think I will ask him to rebuild the distributor. He actually said he could do that but he preferred the solid state. I don't want to solve one problem with another

I can only give you my experience with electronic ignition on motorcycles. I build choppers for fun and every single one gets points. I have had factory and high dollar aftermarket ignition systems leave me stranded on the side of interstates and other fun places. These days I only run points and I carry a complete replacement set of points, weights, and condenser in my tool roll, I think it cost me around $50 bucks. I haven't had a point system leave me stranded yet but if it ever does it would take me all of half an hour or so to swap and set them and I'm on my way.

Yes, there is an advantage to electronic ignition. The advantage is that it does not degrade as you drive, and requires adjustment less often. The carburetor requires adjustment less often too because the initial timing and dwell are not changing over time and affecting idle speed etc. That is a fairly significant advantage, but it is the only one.

An electronic conversion won't fix a bad distributor. All it does is replace a mechanical switch (the points) with a transistor. If it runs like crap with points, it will run like crap with an electronic conversion.


That is not how it works. An electronic conversion does NOT save you from rebuilding the distributor and if a mechanic is telling you that, you need a different mechanic. It might save you from changing a loose bushing, but that is hardly ever the primary issue. The vacuum and centrifugal advance in a distributor need to work and work properly and it makes no difference if points or a transistor is used to switch the coil. Centrifugal advance should be disassembled, lubricated, and then checked to make sure it is doing what it is supposed to be doing. Vacuum advance also needs to be checked for leaks, and also that it advances in the way the shop manual says it should. If the electronic conversion is some little two wire module that all fits inside the distributor, then it depends on the same GROUND (probably a wire) to work that the points depended on. It is amazing how few people check that.

The downside of conversions on 6 volt cars, if there is one, is that it might fail to start in a low battery situation when you might get lucky if you had points. A 6 volt battery is 6.3 volts nominally, and will pull down when cranking. 5 volts maybe? Maybe even less? Maybe as bad as 4.5 when it chugs because the battery is low? That is the compression stroke, right when the ignition needs to fire. That isn't much voltage to work with for something electronic. A typical silicon transistor drops 0.7 volts across one junction, and there are going to be several transistors in an electronic ignition. A conscientious designer would probably find a way around that, but it's not like he has 10 or so volts to work with in the worst case like he does on a 12 volt car. Until it is proven not to be a problem, I am not converting any 6 volt cars.

Years ago I put a electronic assisted ignition on a vehicle, at least every 2 months it was in the workshop or on a tow truck when it failed completely. Since then the various forms of electronic ignition have become common place in the workshop all causing lots of naughty words.
Tony

Thank you for the feedback. I am sold. No electronic ignition.