DIY electronic ignition

[stryped]

I realize kits can be bought but I wondered if this is doable for someone that has some of the parts already?
I have an old 2n tractor. Could a person remove the points and use a Hall effect switch and a magnet on the crankshaft pulley set to signal an HEI or tfi module at number 1 cylinder TDC? The module would then fire the ignition coil? Basically to run your own electronic ignition?
Sent from my iPhone

 

[olddavid]

It would be fun to try but I don't think it would be easy. The early electronic ignition modules designed by real engineers had some short comings and problems so I know I wouldn't get it right. As I recall some of the early units used the points to trigger an electronic/electrical pulse claiming reduced point current and therefore longer point life. That might be a good place to start and see how it goes. Now for the coup de gras. Do you know anything about electronics? If not, my advice would be stick with points or "pay the man" for the module.

 

[Jim L WA]

The first problem that I see is, how will it know to fire number 4 spark plug on it's compression stroke? Then there is the question of adjusting the timing. There isn't any centrifugal advance either.

 

[Jim L WA]

It would be fun to try but I don't think it would be easy. The early electronic ignition modules designed by real engineers had some short comings and problems so I know I wouldn't get it right. As I recall some of the early units used the points to trigger an electronic/electrical pulse claiming reduced point current and therefore longer point life. That might be a good place to start and see how it goes. Now for the coup de gras. Do you know anything about electronics? If not, my advice would be stick with points or "pay the man" for the module.

I had one of those transistor ignitions on an old pickup years ago. It did last a long, long time.

 

[olddavid]

The first problem that I see is, how will it know to fire number 4 spark plug on it's compression stroke? Then there is the question of adjusting the timing. There isn't any centrifugal advance either.

Agreed! Using the original distributor would eliminate most of those problems and I think many do with some modifications.

 

[JMOR]

Built one from scratch when in college. Still have it. Old germanium transistors didn't like very cold weather, though.

https://imgur.com/ROA4PML

https://imgur.com/pBZDMci

 

[stryped]

I would use the original distributor but would use a canned coil instead of square coil

 

[stryped]

The first problem that I see is, how will it know to fire number 4 spark plug on it's compression stroke? Then there is the question of adjusting the timing. There isn't any centrifugal advance either.

I would use the stock distributor. I would assume it would fire right using that

 

[JMOR]

I would use the stock distributor. I would assume it would fire right using that

If trigger off crank, I believe you will need two magnets, 180 apart.

 

[Jim L WA]

If trigger off crank, I believe you will need two magnets, 180 apart.

I got to thinking about my earlier comment yesterday while raking leaves and realized I was 180 degrees out. It would be the number 2 and 3 plugs that wouldn't fire with just a single magnet.

 

[olddavid]

I got to thinking about my earlier comment yesterday while raking leaves and realized I was 180 degrees out. It would be the number 2 and 3 plugs that wouldn't fire with just a single magnet.

I guess that's why the EIs usually use a multi tooth (equal to the number of cylinders) triggering magnet(?) to simulate the distributor shaft lobes.

 

[wore out]

I guess that's why the EIs usually use a multi tooth (equal to the number of cylinders) triggering magnet(?) to simulate the distributor shaft lobes.

IF using a crankshaft trigger, (as JMOR wrote) for a conventional 4-cylinder engine, all cylinders fire at two crankshaft positions, for a 3 or 6 cylinder, 3 positions.

 

[olddavid]

It still has to know where to send the spark and when to advance it at speed. That problem is solved by using a distributor.

 

[JMOR]

It still has to know where to send the spark and when to advance it at speed. That problem is solved by using a distributor.

yep!

 

[teachingscience]

I dont have the article in front of me but I remember some garden tractor pullers using either a GM or a Dodge EI unit and using the points as the trigger. If you did some research, I bet you could do that and use the points in the tractor distributor to trigger it and allow all the original advance and rotor bug to work as normal.

 

[teachingscience]

I dont have the article in front of me but I remember some garden tractor pullers using either a GM or a Dodge EI unit and using the points as the trigger. If you did some research, I bet you could do that and use the points in the tractor distributor to trigger it and allow all the original advance and rotor bug to work as normal.

Here is an article on using mopar. There are other articles out there that explain it better but this is the first one that poped up.
https://www.gofastforless.com/ignition/electronic.htms an article using mopar ignition modules

 

[JMOR]

I dont have the article in front of me but I remember some garden tractor pullers using either a GM or a Dodge EI unit and using the points as the trigger. If you did some research, I bet you could do that and use the points in the tractor distributor to trigger it and allow all the original advance and rotor bug to work as normal.

"....and use the points in the tractor distributor to trigger it and allow all the original advance and rotor bug to work as normal." That is what I did for my home built unit that I posted above. One problem you run into with that is that the trigger current is so small that it doesn't blow the oxidation off the points and eventually, you have to clean them or replace. You need gold contacts for "dry switching".

 

[Kevin in MN]

Her is my take on a home brew EI. This is using a pinto 4cl reluctor and Pickup, I use them to trigger a 2000 GM HEI module and coil

 

[HarryVanderpool]

One problem you run into with that is that the trigger current is so small that it doesn't blow the oxidation off the points and eventually, you have to clean them or replace.

I get to do the same thing with my HIGHLY RELIABLE bone stock ignition. Only, I don't need any of the excess monkey-motion.