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Discussion Starter · #1 ·
Sorry. This might end up long. Electronic ignitions. SBC. I have posted on this topic a couple of times before.
Background: Started out with points system in my '26 T coupe. Points needed replaced at about 10K mile or so. OK. Pretty normal. With the difficulty and high price of obtaining good quality points and condensers, I decided to try a Pertronix. The kind with the whirling magnetic disc under the rotor. Worked fine for about 2-3K miles. Then started acting up. Rough idle/ backfiring. Went back to points until a buddy gave me a chinese RTR small cap HEI distributor. It has worked ok and got probably 5k miles on it. Problem with that RTR distributor is it is not adjustable for mech or vac advance. Set at 20 degrees for both. Made my engine ping if I wasn't careful. I rebuilt the engine and wanted to change the distributor out. Bought an RTR Summit small cap distributor. 15 miles later had to be towed home. Back in goes the chinese RTR distributor. Still not convinced, I bought another Pertronix. This time the Ignitor II lobe sensor model. I got it installed, got it running well enough to back out of the shop to continue the timing process without gassing myself. Backed it out, went to timing it. The idle started kind of fluttering, then the motor died. Would not start. Check spark. NO SPARK!!!. 5 minutes. I couldn't hardly believe it. So I like to keep my T coupe going all the time. Put the chinese RTR back in. Runs just fine for a couple days. Then yesterday I started it to leave in it and it is banging and popping and carrying on. I'm sure it has spark because it runs. Just very badly. I'm positive it is the ignition. Now I have to put together a points distributor just to get it running.
So what the heck is going on??? It must be the way I am holding my mouth. There are only 2 wires in the car's system going to the ignition system. The 12+ from ignition switch to coil and tach feed. It has a good heavy ground engine to frame.
An HEI won't fit due to firewall interference problems. So not an option. In one of my previous posts 57nomad posted info about converting a points distributor to chevy HEI. I really don't want to attempt this conversion myself. It looks like a science experiment. He also suggested a fella named Dave that does that conversion. I contacted him, but he is out of commission due to a brown recluse spider bite on his right hand.
I really would like to have an electronic ignition in this car (obviously, judging by how persistent I've been). But there's gotta be something wrong somewhere to cause 4 different ignition systems to go bad. I know....I am the only thing common to all 4 failures, but I really don't think it's me. Karma?
Somebody enlighten me, PLEASE!
 

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I've read about problems with what's referred to as a " noisy" electrical system . You'll have to find someone way smarter than me to explain that . From what I could gather , it has to do with things limke ground faults , voltage spikes and electrical back feeds , so alternator , ignition switch , electrical components like gauges ( tach) etc. Maybe someone can chime in ..
 

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Plus of possibilities all the most is points run on 6 to 9 volts so somewhere in the run position wiring of the ignition switch is a resistor, it can be in line somewhere, a resistive wire from switch to coil, or a stand alone under hood resistor. These whatever the configuration need to go, electronic ignitions are really designed to operate on full B+ voltage of 12.5 volts. Some advertise as being able to operate on resistor voltage but they never do it well.

Another is ignition electrical noise, electronics need to be protected from the spark arcs in the cap and plugs, this means the use of resistor secondary wires and plugs, the wires can be spiral wound as an alternative, straight metallic plug wires are out.

Grounds, can’t have too many; it’s a good idea to wire the intake and heads and maybe even the distributor body to take them to a chassis or battery ground terminal connection to insure there are no transient voltages finding a ground potential through the electronics as this smokes them expensive little parts.

Bogie
 

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Discussion Starter · #5 ·
Plus of possibilities all the most is points run on 6 to 9 volts so somewhere in the run position wiring of the ignition switch is a resistor, it can be in line somewhere, a resistive wire from switch to coil, or a stand alone under hood resistor. These whatever the configuration need to go, electronic ignitions are really designed to operate on full B+ voltage of 12.5 volts. Some advertise as being able to operate on resistor voltage but they never do it well.
I have a resistor on the car for the points, but wire around it for the electronic stuff. Should have mentioned that to stat with.
Another is ignition electrical noise, electronics need to be protected from the spark arcs in the cap and plugs, this means the use of resistor secondary wires and plugs, the wires can be spiral wound as an alternative, straight metallic plug wires are out.
On this car I am using spiral wound wire and resistor plugs, but I have a horror story to tell about electrical noise. Not ruling that out.
Grounds, can’t have too many; it’s a good idea to wire the intake and heads and maybe even the distributor body to take them to a chassis or battery ground terminal connection to insure there are no transient voltages finding a ground potential through the electronics as this smokes them expensive little parts.
I have been thinking about grounding the heads, intake and distributor body. Pretty easy and can't do anything but help even if it's not the problem.
 

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Discussion Starter · #6 ·

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Discussion Starter · #7 ·
I am waiting for dinner so I'll tell that electrical ignition noise story. I put a magneto and copper plug wires in my 27 roadster with a pretty hot 383. Runs great. Later I decide to put electric power steering in it. Got it all installed. Turn the key on without starting the engine and the power steering works great. So I hop in it to take it for a test drive, start it up, back it out and turn to go down the drive and the steering acts like a regular hydraulic system that is very low on fluid. Jerky, you know. Well I can't drive it like that. What the heck? So I figure it is RFIs. I spent a couple of days building enclosures for the steering and controller out of copper cloth. That was a miserable failure. So sitting eating dinner that evening I thought about those copper plug wires. Having another set of spiral core wires, I changed them out and no more steering problems. That makes me wonder if when I had the copper plug wires in it, if I drove up next to a Saturn Vue would it mess up his steering?:oops:
Anyway, not applicable to the topic, but kind of interesting.
 

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try the pertronics again, my son has had the same one for 15 years in his 68 elco
he's driven it coast to coast a couple times, i've never heard of one going out that quick
 

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Davis has a distributor that uses an mag pickup and a regular HEI module with a small cap. HEI modules are easy to change and carry a spare.
 

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Discussion Starter · #13 ·
try the pertronics again, my son has had the same one for 15 years in his 68 elco
he's driven it coast to coast a couple times, i've never heard of one going out that quick
Yeah, 5 minutes or less. Being a 4 time loser, I'm not sure I'm ready to jump back in. I found some NOS GM Delco points and condensers on Ebay. At least for now I'm going back to the good ol' points. In 50 years of running sbc points distributors, I have never been left stranded by them. I think I need to find some reason for the failures before I could have confidence in another electronic ignition.
 

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You know you can still purchase Accel brand points and condensers. Used to run those back in the day and good for over 7000 RPM.
 
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Discussion Starter · #15 ·
Davis has a distributor that uses an mag pickup and a regular HEI module with a small cap. HEI modules are easy to change and carry a spare.
I wasn't familiar with Davis. I checked this out. They do have a small cap distributor. I may give them a call, pretty price competitive with Summit's RTR small cap. The note on their website says this distributor is 4-6 weeks out. It'll run on points that long! I think I will at least call them. I can give them the whole story and see what they say. Thanks.
 

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I am waiting for dinner so I'll tell that electrical ignition noise story. I put a magneto and copper plug wires in my 27 roadster with a pretty hot 383. Runs great. Later I decide to put electric power steering in it. Got it all installed. Turn the key on without starting the engine and the power steering works great. So I hop in it to take it for a test drive, start it up, back it out and turn to go down the drive and the steering acts like a regular hydraulic system that is very low on fluid. Jerky, you know. Well I can't drive it like that. What the heck? So I figure it is RFIs. I spent a couple of days building enclosures for the steering and controller out of copper cloth. That was a miserable failure. So sitting eating dinner that evening I thought about those copper plug wires. Having another set of spiral core wires, I changed them out and no more steering problems. That makes me wonder if when I had the copper plug wires in it, if I drove up next to a Saturn Vue would it mess up his steering?:oops:
Anyway, not applicable to the topic, but kind of interesting.
To cancel RFI, use plastic not metal. And yes, your Copper core plug wires can sometimes wreak havoc on nearby electronics like security cameras and recieving weak Radio stations. What do the tunes sound like when you are driving, if you have any?
 

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I have always had good luck with mallory unilte conversions. Never missed a lick. Full 12V to dist. I think. With a hot coil. 7000 rpm motors.
 
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