g741.org

Ok, I just Googled them and they are in business and advertise as making automotive coils. Has anyone tried to call them before I try?

outpostm37 wrote:New owner here with a '63 M37 230cu inch engine. I have replaced the coil in December of 2017 with a chrome Chinese unit purchased a month earlier. My truck has the Petronics 161A unit inside the distributor to get rid of the points. I have the same issue as many others with stalling. The truck will start great cold, may die in 20 seconds to 15 minutes. First I thought it was a fuel issue. Each time, I checked the float bowl and it was full of gas. When the engine dies, it is like someone pulls the plug out of the wall. No stumbling, back firing or anything else. I called the tech line of Pertronics. The tech stated that the unit is designed to function with a coil of 6 to 8 ohms resistance on the primary. He said that the unit will shut down if the voltage drops below 16ish volts. This may be happening with my chrome coil as it is at 11.2 ohms on the primary. My next check is to take the distributor cap off, turn the system on, and check voltage across the red and black Pertronics leads to verify voltage is above the Tech's info of greater than 16 volts. If anyone has other info to get rid of this malady, please chime in.

The original NOS coils had a primary resistance of 5-6 ohms. The Chinese coils have the higher resistance you mention and that would normally indicate a bad coil on an American made coil but this is an unknown value on the Chinese coils because we do not know if they have more (Unlikely) or less wraps of wire in the primary of the coil. More wraps would give higher resistance and less wraps would give lower resistance. I think I have that right, it has been a while since I was into that stuff. No matter what, we don't have a factory value so we can't diagnose based on what the value of the American coils were. Every Chinese coil I have tested came out in the 11 ohm range so that tells me it is normal for those coils.

rickf wrote:Ok, I just Googled them and they are in business and advertise as making automotive coils. Has anyone tried to call them before I try?

I was going to contact them, but feel free to do so. I didn't have any luck with the company that made the fuel shut off valves, but maybe you'll have success on the coils.

I just got home from the pain docs, I will give them a call tomorrow. This is also of interest to the M-151 crowd on my other forum.

outpostm37 wrote:New owner here with a '63 M37 230cu inch engine. I have replaced the coil in December of 2017 with a chrome Chinese unit purchased a month earlier. My truck has the Petronics 161A unit inside the distributor to get rid of the points. I have the same issue as many others with stalling. The truck will start great cold, may die in 20 seconds to 15 minutes. First I thought it was a fuel issue. Each time, I checked the float bowl and it was full of gas. When the engine dies, it is like someone pulls the plug out of the wall. No stumbling, back firing or anything else. I called the tech line of Pertronics. The tech stated that the unit is designed to function with a coil of 6 to 8 ohms resistance on the primary. He said that the unit will shut down if the voltage drops below 16ish volts. This may be happening with my chrome coil as it is at 11.2 ohms on the primary. My next check is to take the distributor cap off, turn the system on, and check voltage across the red and black Pertronics leads to verify voltage is above the Tech's info of greater than 16 volts. If anyone has other info to get rid of this malady, please chime in.

Just an update:
I removed the distributor cap on my 1963 M37 230 engine. With my Pertronix disconnected, took my Fluke meter, set to ohms, shorted the leads to verify zero resistance between them as not to add to my readings. The primary coil ohms reading (cold engine) was 11.2.This is a new chrome Taiwan? coil.
The secondary reading was 16.6k ohms. Next I removed the electrical filter that screws to the bottom of the distributor. Disassembly revealed that the rubber grommet cracked in several places and the feed wire had several broken strands of wire that were sticking out sideways most likely shorting to the side with vibration. I replaced the original wire with new 14 gauge wire soldering and shrink tubing for added protection. After reassembly of the feed wire/filter, and connecting the coil back up, I turned the key to the on position only. Not starting the engine. The voltage across the two Pertronics wires was 23.65vdc. Battery voltage was at 25.6vdc. This reading gave me a warm fuzzy feeling about the required 16vdc at the Pertronics. Drove the vehicle on two separate occasions with no dying. I may have remedied my electrical issue once and for all.

Filter that screws to the bottom?

I've seen them in the housing at the input wire.
I've seen them on the firewall.
And once, i saw one that sat under the coil.
Ive never seen one screwed to the bottom.

Do you have a picture? I'm curious about yet another version.

just me wrote:Filter that screws to the bottom?

I've seen them in the housing at the input wire.
I've seen them on the firewall.
And once, i saw one that sat under the coil.
Ive never seen one screwed to the bottom.

Do you have a picture? I'm curious about yet another version.

I wondered about that description, too, but figured it was the radio suppression condenser on the primary wire input on the later style ignitors. When the ignitor (okay, distributor ) is installed on the engine, the radio condenser is at the bottom.

just me wrote:Filter that screws to the bottom?

I've seen them in the housing at the input wire.
I've seen them on the firewall.
And once, i saw one that sat under the coil.
Ive never seen one screwed to the bottom.

Do you have a picture? I'm curious about yet another version.

Sorry guys, when I said "filter" I meant electrical condenser that is mounted to the bottom of the distributor.
It filters out crackling for radio operation in the vehicle?