The Chopper Compendium

I recently almost missed an event I really wanted to attend over a dead condenser. So I decided to convert my scouts to electronic ignition tripped by the points. So I thought I'd do a how to.
Why HEI with points?
1 No condenser! It's getting hard to find a quality condenser that hasn't ben stored for years.
2 points last practically forever! With a current flow of around 12 Milliamps they just don't burn.
3 Cost! new solid state distributors. timers and conversion kits are very expensive. I spent less than $50.00 for two,
4 All the spark you could ever want. The GM 4 pin module will work with any coil .5 ohms or greater resistance, which means you can run coils with very high output. The one on my Jeep has a.6 ohm transformer style coil and makes almost 2"" of spark.
% Easily change back to a standard Kettering style points ignition
For this demo I'm going to do two a budget build and a more costly version. In the past I have used the late 90s through early 2000s GM heat sink for $10 to $12 all of a sudden they are $40.00 and up so I bought this one at a Salvage for a dollar





Left universal heat sink 3 for $9.00 Right used GM heat sink $1.00 from Capital Scrap



1k q/4 watt resistors Less than $5.00 a hundred years ago.
1/32 electronics solder 1LB $30 some odd years ago
Computer grade Thermal Paste about $13
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Chinesey 4pin module almost $9.00 Standard LX301 about $25 from a parts store.




once you have all the parts the first thing to do is to tin (coat in solder) both ends of the resistor leads and the very back of the B and G terminals. Then solder the resistor between the B & G terminals.

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Then clamp the module to the heat sink and drill the heatsink through the module.



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If the locating pins hit the heatsink you can either remove them or drill holes for them. I generally cut them off.

Snip File
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That's all for tonight
Dusty

So Your reasoning is that the amperage to trigger the ignition module is much lower than the amperage that would be required to charge the coil.

Yes I'm feeding the points through the 1K resistor. Which gives around 12 -15 milliamps. Whereas the module will support a coil resistance of .5 ohms or 6 amps of current.
Dusty

Is the reason for using the points instead of a reluctor and pickup coil so that You can have it look stock?

The points have been doing their job for 84 years why spend $500.00 to convert it to a reluctor or mag pickup and if the module does fail it takes about 5 mi9nutes to convert it back to Kettering ignition.
Dusty

Ahhh, Makes sense. Much less wear and tear on the points due to the reduced current. back in My younger days an older guy showed me a trick where you could lick your finger tips. you then touched one finger to the terminal on the ignition module, and touched the finger on the other hand to the positive battery terminal. That was enough current to trigger the module and make the coil spark. another way was to take a test light connected to the positive terminal and then take the probe of the test light to the trigger terminal of the module. this would cause the coil to spark.

As I remember it, on a breaker point system, the points are closedand the coil windings are energized, then when the points open, the coil will spark. Will the ignition module work that way? My thinking is that the electrical pulse is what it would take to trigger the module.

Am I over thinking this?

You're on the right track it does now fire when the points close. The module normally holds the coil to ground then when it receives a fer milli amps of current from the pickup coil it opens the coil ground. The 1k resistor I hook from hot to one if the pickup terminals, flows through the module then the points to ground then stops when the points open. It wouldn't matter which to the terminals that go to the pickup coil W or G, I hook the resistor to since they have no polarity. But it seems neater to hook to the green and just use the wires already on the resistor.
Dusty

So, the module is not looking for a specific signal, but rather looking for a change of a signal.

I remember the pickup coils in the GM distributor would generate an a/c signal, and the reluctor would change that signal.

So, the module is not looking for a specific signal, but rather looking for a change of a signal.

I remember the pickup coils in the GM distributor would generate an a/c signal, and the reluctor would change that signal.

Yes, a pulsed DC is pretty similar to half of an AC signal. It seems to work just as well with mag pickups as well.
Dusty

If the heat sink has been used before, clean the old thermal paste off completely.

Then Spread a thin coating of thermal pate over the metal base of the module then fasten the mounting screws. Carefully clean any thermal grease that squeezes' out.



Now I'm waiting for the Dow Corning 732 that Amazon lost somewhere.
Dusty

Started the hardest part of this conversion for me today! Deciding where to put the module that won't affect the looks of my chopper or be too hard to get to for road side repairs. Hiding is always a go to but the only two hidden spots are in the tank tunnel which would require removing the tank and seat for access son not very hight on my list ot under the battery box which is even harder to access and is already full of wiring. So a few visible spots.

Maybe build a bracket right beside the coil?

Or maybe the cheaper unit?



Or maybe under the seat mount? Awful lot of long wiring runs but would be easy to mount either one there.

or on the outside of the seat mount?


Or on the front tank mount? Naw!!



I even considered the end of the alternator since it looks so out of place on a bike this age anyway but not enough room behind the end cover

Think Ill consider it awhile
Dusty

Just catching up on unread posts. Did you ever choose a mounting location?
Good info on switching to HEI with points. I've had charging problems on the road, it's a huge PITA
with electronic.
I run a Crane HI-4 which I like the performance and adjustable settings, but I've never carried a spare.
Maybe I should. They aren't very big.

Nope gave up on it! it won't work on a V-twin with uneven points cam lobes because it fires on points closing. I tried it with the points opening tripping a transistor to close the circuit. And it ran briefly but wasn't what I was looking for. It was going to require a circuit board and heat sink so I went back to points. When it was 1 resistor and a heat sink like the one on my Jeep it was great not so much with transistors boards another heat sink.
dusty