I have an old Ford 8N type tractor with a front mount distributor. To make it more reliable in terms of starting since it sits outside, I have been toying with the idea of making my own electronic ignition. I would place a hall sensor in the distributor and magnets on the shaft to signal the sensor when to trigger. The sensor would then either trigger the ignition coil directly or trigger an ignition module ( like a TFI or HEI) and then the module would trigger the coil.
I assume I need a digital, non latching, unipolar Hall effect sensor? Does anyone have any recommendations for a sensor or magnet or other advice?
Any help is appreciated!

 

I have an old Ford 8N type tractor with a front mount distributor. To make it more reliable in terms of starting since it sits outside, I have been toying with the idea of making my own electronic ignition. I would place a hall sensor in the distributor and magnets on the shaft to signal the sensor when to trigger. The sensor would then either trigger the ignition coil directly or trigger an ignition module ( like a TFI or HEI) and then the module would trigger the coil.
I assume I need a digital, non latching, unipolar Hall effect sensor? Does anyone have any recommendations for a sensor or magnet or other advice?
Any help is appreciated!

I know it's old, but presumably even an engine that old has some form of ignition advance mechanism?

 

The question of an Advance-Mechanism is a good one,
although there's a good chance that it doesn't have one at all.

My preference would be two Optical-Interrupters along with
two "Wasted-Spark" type Automotive-Coils, and two GM-HEI-Ignition-Modules.
This would eliminate long Spark-Plug-Wires,
and the Spark having to jump a gap inside the Distributor.

This will completely eliminate having to clean or replace the Cap and Rotor on the Distributor.

This setup will work with any number of Cylinders.

This can also work with late-model GM-LS "Coil-On-Plug" Ignition-Coils,
but they are somewhat more expensive, ( if You buy them new ),
although they eliminate the need for separate HEI-Ignition-Modules since
the Ignition-Module is built-in to each individual Coil.
You can get this stuff from your closest Junk-Yard, ( Auto-Parts-Recycler ).

In either case, a mounting-bracket will have to be fabricated to
mount the Coils to the Cylinder-Head, or at least, very near to the Spark-Plugs.

This may sound like a lot of trouble,
but You will never have to work on the Ignition-System again,
and,
it will probably be the last time You will ever see the Spark-Plugs.

Your new, and probably your last, Spark-Plugs can be gapped at 0.080 inch
since old Tractors have very low Compression-Ratios,
this will reduce mis-fires to basically zero, and make starting much easier.

If the Engine is being re-built,
I would recommend that You do anything possible to
increase the Compression-Ratio to at least 9 to 1,
this will tremendously increase the Efficiency and Power of the Engine with no draw-backs,
excepting that You can no longer run the Engine on Kerosene or really bad Gasoline.
Low-Grade Automotive-Gasoline will be perfectly safe at a 9 to 1 CR.

If the Compression-Ratio is increased to 9 to 1 as recommended,
change the Plug-Gap recommendation to ~0.060 inch.
.
.
.

 

The question of an Advance-Mechanism is a good one,
although there's a good chance that it doesn't have one at all.

My preference would be two Optical-Interrupters along with
two "Wasted-Spark" type Automotive-Coils, and two GM-HEI-Ignition-Modules.
This would eliminate long Spark-Plug-Wires,
and the Spark having to jump a gap inside the Distributor.

This will completely eliminate having to clean or replace the Cap and Rotor on the Distributor.

This setup will work with any number of Cylinders.

This can also work with late-model GM-LS "Coil-On-Plug" Ignition-Coils,
but they are somewhat more expensive, ( if You buy them new ),
although they eliminate the need for separate HEI-Ignition-Modules since
the Ignition-Module is built-in to each individual Coil.
You can get this stuff from your closest Junk-Yard, ( Auto-Parts-Recycler ).

In either case, a mounting-bracket will have to be fabricated to
mount the Coils to the Cylinder-Head, or at least, very near to the Spark-Plugs.

This may sound like a lot of trouble,
but You will never have to work on the Ignition-System again,
and,
it will probably be the last time You will ever see the Spark-Plugs.

Your new, and probably your last, Spark-Plugs can be gapped at 0.080 inch
since old Tractors have very low Compression-Ratios,
this will reduce mis-fires to basically zero, and make starting much easier.

If the Engine is being re-built,
I would recommend that You do anything possible to
increase the Compression-Ratio to at least 9 to 1,
this will tremendously increase the Efficiency and Power of the Engine with no draw-backs,
excepting that You can no longer run the Engine on Kerosene or really bad Gasoline.
Low-Grade Automotive-Gasoline will be perfectly safe at a 9 to 1 CR.

If the Compression-Ratio is increased to 9 to 1 as recommended,
change the Plug-Gap recommendation to ~0.060 inch.
.
.
.

I am not rebuilding but decided I need to do something. The tractor sits outside and is only used once in awhile. But when I do need it and go to start it it will not start unless the points are sanded. The ignition has always been the weak point of this tractor.
I am a little new on some electronics. What is an optical interceptor and how would I install it for my situation? I like your idea and wondered before if somehow coil near plug or coil on plug would be possible.

 

Here is a cautioning suggestion: If the breaker points usually need sanding then it is possible that the distributor assembly is not adequately sealed, in which case an optical sensor may also become contaminated a bit. So better sealing might be required. OR it may be that those points are becoming rusty, or corroded, and needing to be replaced with a different material.

 

Here is a cautioning suggestion: If the breaker points usually need sanding then it is possible that the distributor assembly is not adequately sealed, in which case an optical sensor may also become contaminated a bit. So better sealing might be required. OR it may be that those points are becoming rusty, or corroded, and needing to be replaced with a different material.

The more I think about it, in a rough environment inside a distributor, wouldn’t a regular hall sensor with a magnet trigger work better?

 

The first thing to look into is does this Tractor-Engine use the same Distributor that
was used on some other Ford Automotive-Engine.

It's "possible", although not very likely,
that there is a Ford Electronic-Distributor that will drop right in place.

The next attempt should be to install a new set of Points, gap them correctly,
then use the Points to fire an Electronic-Ignition-Box.
This may be the cheapest and simplest solution,
along with sealing the Distributor-Cap with RTV-Silicone-Rubber-Sealant.

A Hall-Sensor, or Optical-Interrupter, setup will not be affected by any Condensation.

Check to make sure that the Engine has a free-flowing Crankcase-Vent, or vented Oil-Fill-Cap.
If the crankcase is not properly vented, blow-by-pressure can build-up inside the Engine and
force Oil-Vapor and Moisture into the Distributor, resulting in fouled Points.

One other odd thing to check is the Condenser for the Points.
The Condenser should be replaced along with the Points anytime the
Points show signs of "Pitting" or contact wear.
You can "CLEAN" the Points with ~600-Grit Wet-or-Dry-Sandpaper "ONCE",
the second time any "cleaning" is required,
the Points and Condenser should be REPLACED with new parts,
and the actual problem should be found and corrected.

If You are dead-set on eliminating your Points,
be prepared for some level of precision-machine-work if You
can't find an Electronic-Ford Distributor that will just "Drop-In".
There are at least 4 major manufacturers that sell dedicated Magnetic or Optical "Kits",
hundreds of part-numbers,
but as to whether or not they're going to have a Kit that will work with an old Ford Tractor,
that may be another story.
The most prolific of these companies is called "Pertronics",
I suggest that You call them and tell them what You have, and what You expect.
Their Kits usually run around ~$130.oo USD,
and they have an excellent, long-standing, reputation, and all of their stuff is made in the USA.
.
.
.

 

This looks like a cheap and easy solution
As lowQ said, Pertronics also makes a kit if you want "name brand"


https://www.amazon.com/dp/B0CW1FFYN...psc=1&sp_csd=d2lkZ2V0TmFtZT1zcF9ocXBfc2hhcmVk

 

The first thing to look into is does this Tractor-Engine use the same Distributor that
was used on some other Ford Automotive-Engine.

It's "possible", although not very likely,
that there is a Ford Electronic-Distributor that will drop right in place.

The next attempt should be to install a new set of Points, gap them correctly,
then use the Points to fire an Electronic-Ignition-Box.
This may be the cheapest and simplest solution,
along with sealing the Distributor-Cap with RTV-Silicone-Rubber-Sealant.

A Hall-Sensor, or Optical-Interrupter, setup will not be affected by any Condensation.

Check to make sure that the Engine has a free-flowing Crankcase-Vent, or vented Oil-Fill-Cap.
If the crankcase is not properly vented, blow-by-pressure can build-up inside the Engine and
force Oil-Vapor and Moisture into the Distributor, resulting in fouled Points.

One other odd thing to check is the Condenser for the Points.
The Condenser should be replaced along with the Points anytime the
Points show signs of "Pitting" or contact wear.
You can "CLEAN" the Points with ~600-Grit Wet-or-Dry-Sandpaper "ONCE",
the second time any "cleaning" is required,
the Points and Condenser should be REPLACED with new parts,
and the actual problem should be found and corrected.

If You are dead-set on eliminating your Points,
be prepared for some level of precision-machine-work if You
can't find an Electronic-Ford Distributor that will just "Drop-In".
There are at least 4 major manufacturers that sell dedicated Magnetic or Optical "Kits",
hundreds of part-numbers,
but as to whether or not they're going to have a Kit that will work with an old Ford Tractor,
that may be another story.
The most prolific of these companies is called "Pertronics",
I suggest that You call them and tell them what You have, and what You expect.
Their Kits usually run around ~$130.oo USD,
and they have an excellent, long-standing, reputation, and all of their stuff is made in the USA.
.
.
.

There is definitely no other Ford distributor that will fit this tractor.
I actually have considered using the points to fire a Ford TFI ignition module. However I wondered if I would have the same problem as the points would still need to work in order to switch the module on.

 

This looks like a cheap and easy solution
As lowQ said, Pertronics also makes a kit if you want "name brand"


https://www.amazon.com/dp/B0CW1FFYN...psc=1&sp_csd=d2lkZ2V0TmFtZT1zcF9ocXBfc2hhcmVk

That is for a side mount distributor only. I have a front mount.

 

The points would probably trigger that "Mark Ten" CD system I ran in my 1965 Barracuda back in 1972-73. It used a higher impedance input so it could accept a few ohms series resistance on the points, and the spark would jump half an inch thru ope air. And the voltage rise time was fast enough that it would fire fouled plugs. And it did not demand a whole 12 volts to deliver a serious spark. So it might work on a six volt tractor with no changes.

 

The points would probably trigger that "Mark Ten" CD system I ran in my 1965 Barracuda back in 1972-73. It used a higher impedance input so it could accept a few ohms series resistance on the points, and the spark would jump half an inch thru ope air. And the voltage rise time was fast enough that it would fire fouled plugs. And it did not demand a whole 12 volts to deliver a serious spark. So it might work on a six volt tractor with no changes.

My tractor is converted to 12 volts. What omission that system ?

 

"" However I wondered if I would have the same problem,
as the points would still need to work in order to switch the module on. ""

Normally the Points have to handle a substantial amount of CURRENT to charge the Ignition-Coil,
but using the Points to operate an Electronic-Module that handles the high-Current
takes all of the Load off of the Points and Condenser combination,
this eliminates Pitting and wear of the Points.
No fussy Condenser is wanted or required with an Electronic-Module.

Replacing the Points with an Electronic-Pickup does however increase overall reliability,
since there is no "mechanical-wear" that takes place,
and contamination is largely irrelevant.
( but the Distributor-Cap must still be kept clean or new )

The Points, if retained, would still need an annual inspection,
and a check of the Points-Gap,
and a cleaning of the interior of the Distributor and Cap with "Brake-Clean-Spray",
and adding a drop of Oil to the Felt-Oiling-Pad that lubricates the Points-Cam.

I might be just crazy enough to install a .......
Crank-Trigger,
and a GM Single-Barrel TBI Throttle-Body-Injector,
4 GM "Coil-near-Plug" Ignition-Coils,
and a "Micro-Squirt" Fuel-Injection-Computer to run it all.
But that's probably a good deal more Money than you'd like to spend. ( ~$5 to ~$700.oo ish )
Although it would be really nice to have instant cold-weather starts and snappier response.
.
.
.

 

Although it would certainly be nice to go to a hall sensor detector, I'm not sure it's worth the likely significant effort to install for an engine that's only used occasionally.
Since a electronic ignition would greatly reduce the load on the points, I think they would reliably trigger the electronics, even if unused for a long period of time.
So as a start, you might try just adding an electronic module that fires the coil triggered by the points and see how that works.

Just my two cents.

 

"" However I wondered if I would have the same problem,
as the points would still need to work in order to switch the module on. ""

Normally the Points have to handle a substantial amount of CURRENT to charge the Ignition-Coil,
but using the Points to operate an Electronic-Module that handles the high-Current
takes all of the Load off of the Points and Condenser combination,
this eliminates Pitting and wear of the Points.
No fussy Condenser is wanted or required with an Electronic-Module.

Replacing the Points with an Electronic-Pickup does however increase overall reliability,
since there is no "mechanical-wear" that takes place,
and contamination is largely irrelevant.
( but the Distributor-Cap must still be kept clean or new )

The Points, if retained, would still need an annual inspection,
and a check of the Points-Gap,
and a cleaning of the interior of the Distributor and Cap with "Brake-Clean-Spray",
and adding a drop of Oil to the Felt-Oiling-Pad that lubricates the Points-Cam.

I might be just crazy enough to install a .......
Crank-Trigger,
and a GM Single-Barrel TBI Throttle-Body-Injector,
4 GM "Coil-near-Plug" Ignition-Coils,
and a "Micro-Squirt" Fuel-Injection-Computer to run it all.
But that's probably a good deal more Money than you'd like to spend. ( ~$5 to ~$700.oo ish )
Although it would be really nice to have instant cold-weather starts and snappier response.
.
.
.

lol… I actually thought about it except utilizing sequential injection instead of the TBI and using a cheaper ECU like speedurino. I am interested in learning more about diy ecu’s since I also have a car project where I could use one.

 

Although it would certainly be nice to go to a hall sensor detector, I'm not sure it's worth the likely significant effort to install for an engine that's only used occasionally.
Since a electronic ignition would greatly reduce the load on the points, I think they would reliably trigger the electronics, even if unused for a long period of time.
So as a start, you might try just adding an electronic module that fires the coil triggered by the points and see how that works.

Just my two cents.

That is probable what I will do although I am a little afraid of the same thing happening with the points corroding and not able to send a signal to the module.
One plus is I think if using the module I cal eliminate the ballast resister and other resisters in the ignition circuit as well as use a low resistance and “hotter” coil like the coils that come from factory with the cars with the ignition module.
Here is a tutorial of what I would do to use the points to trigger an ignition module: https://fordsix.com/threads/upgrade-points-distributor-to-fire-with-a-tfi-module.85142/

 

I am a little afraid of the same thing happening with the points corroding and not able to send a signal to the module.

That's possible of course, but I would expect even corroded points to be able to carry the small trigger current that the module requires.

 

When using a TFI, or a HEI Module,
the "Ballast-Resistor" may need to be retained depending on the Ignition-Coil that is used.

A Speedueno is only for those who have extensive experience in designing their own Circuits and PCBs.
Micro-Squirt, and Mega-Squirt, on the other hand,
eliminate all that fabrication work and custom-Coding that's generally required with Speedueno,
in other words, the learning-curve is much much easier with a Micro/Mega-Squirt,
and they come completely sealed from the weather,
and with a wiring-harness,
and excellent Tuning-Software.

I wouldn't bother with Sequential-Injection on a Tractor,
but it's usually worthwhile on a Car or Truck.

A Tractor NEEDS MORE COMPRESSION, more than anything else.

Points generally don't "corrode", they are "pitted" by constant sparking from heavy Current.

GM-LS-style "Coil-Near-Plug" Ignition-Coils don't require a separate "Ignition-Module" to work,
they are completely self-contained, and operate on a 5-Volt-Switched-Ground-Signal, at very low Current.
The only requirement is two Optical-Interrupters and a slotted disc to replace the Points,
and a Regulated +5-Volt Power-Supply.
( The slotted-disc can be mounted to the Crankshaft-Pulley, only 1 slot is needed )
Then connect two-plus-two Coils in parallel for a "Wasted-Spark" configuration.
( Cylinders 1&4, and 2&3 fire at the same time,
180-degrees apart, on every Crankshaft rotation ( NOT Camshaft-rotation ) )

For a Flat-Head Tractor-Engine, a fixed Ignition-Advance of around ~15-degrees should work just fine,
but having an ECU controlled 12X12 Timing-Table would, of course, be ideal.
.
.
.

 

When using a TFI, or a HEI Module,
the "Ballast-Resistor" may need to be retained depending on the Ignition-Coil that is used.

A Speedueno is only for those who have extensive experience in designing their own Circuits and PCBs.
Micro-Squirt, and Mega-Squirt, on the other hand,
eliminate all that fabrication work and custom-Coding that's generally required with Speedueno,
in other words, the learning-curve is much much easier with a Micro/Mega-Squirt,
and they come completely sealed from the weather,
and with a wiring-harness,
and excellent Tuning-Software.

I wouldn't bother with Sequential-Injection on a Tractor,
but it's usually worthwhile on a Car or Truck.

A Tractor NEEDS MORE COMPRESSION, more than anything else.

Points generally don't "corrode", they are "pitted" by constant sparking from heavy Current.

GM-LS-style "Coil-Near-Plug" Ignition-Coils don't require a separate "Ignition-Module" to work,
they are completely self-contained, and operate on a 5-Volt-Switched-Ground-Signal, at very low Current.
The only requirement is two Optical-Interrupters and a slotted disc to replace the Points,
and a Regulated +5-Volt Power-Supply.
( The slotted-disc can be mounted to the Crankshaft-Pulley, only 1 slot is needed )
Then connect two-plus-two Coils in parallel for a "Wasted-Spark" configuration.
( Cylinders 1&4, and 2&3 fire at the same time,
180-degrees apart, on every Crankshaft rotation ( NOT Camshaft-rotation ) )

For a Flat-Head Tractor-Engine, a fixed Ignition-Advance of around ~15-degrees should work just fine,
but having an ECU controlled 12X12 Timing-Table would, of course, be ideal.
.
.
.

Why would I need to use the ballast resistor if using an e coil similar to what vehicles that came from factory with a TFI module used?
Any be the way, I agree with the mega squirt comments, but it is much more expensive

 

I have used the single coil wasted spark type for electric fence with just using one spark source secondary, firing a Mosfet on the primary at the required time.
You would just need to chassis GND the other side of the coil secondary,