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Use of electronic ignition modules with points distributors
https://slantsix.org/forum/viewtopic.php?t=46672		 Page 1 of 2
Author:  olafla [ Sat Oct 15, 2011 9:54 pm ]
Post subject:  Use of electronic ignition modules with points distributors
I made a quick, and not very thorough search for this subject in the forum, without finding any information about it, so I hope this is relevant, new info for some of you.

The big problem with points is that they have a limited life, they will burn, they need regular adjustment and maintenance. They burn because you send the full voltage through them, every time they switch on and off the voltage to the primary circuit in the coil, by opening and closing.

If you instead let the points act as a trigger only, by operating in a manner similar to the components in an electronic distributor, to trigger an electronic module, the low voltage through the points will increase their life dramatically, the module will do all the switching work, and provide a hot spark as well.

Here are links to some different approaches, they all let you keep your points distributor intact.

One is a bolt-on using a Ford TFI module, and only requires some wire and connectors. The Ford TFI module is the only commonly used module that is triggered by a signal going from negative to positive, just like the points normally operate. This setup allows you to just disconnect the module and reconnect the condenser, to have an ordinary, fully operating points ignition system, if the module fails. Points to Electronic Ignition Cheap & Easy with Ford TFI

The other two require a positive to negative signal, as given when the points close, which means that the ignition has to be adjusted to work properly, after a module fail.

Here is a Ford guy using a Mopar ECU with his points distributor: Dirt Cheap Electronic Ignition

This one is using a HEI module on a Kawasaki, but require making some circuits with electronic components to get it to work properly. GM HEI Ignitor for Points

Olaf.
Author:  SlantSixDan [ Sat Oct 15, 2011 10:45 pm ]
Post subject: 
…and the point of this half-baked effort would be? You still have the mechanical wear of the points' rubbing block against the point cam, and you still have the variation in triggering accuracy caused by point cam and distributor bushing wear, and you still have periodic maintenance in the distributor. Why mess around with a halfaѕѕed job like this? Just get a readily-available electronic distributor and do the job correctly. Or if for whatever reason you feel the need to keep the points distributor, throw a Pertronix kit in it.

A long time ago (early 1960s) there was a reason to trigger an electronic brain box with breaker points: reliable, inexpensive non-contact triggers weren't yet available. Now we have lots of different varieties of same, so there's no reason to use such an inferior solution as breaker points.

I guess I'm of the opinion that a job worth doing is worth doing right, especially when it's easier to do it right than to do it wrong.

(Moreover, that Ford TFI module is notoriously unreliable even when it's at "home" under the hood of a Ford. Again: why cobble up an unreliable Frankenstein of an ignition system when inexpensive, reliable options are all over the place?)
Author:  DusterIdiot [ Sun Oct 16, 2011 12:25 am ]
Post subject:  Uh Huh...
Quote:
You still have the mechanical wear of the points' rubbing block against the point cam, and you still have the variation in triggering accuracy caused by point cam and distributor bushing wear, and you still have periodic maintenance in the distributor.
I'd have to second that...Having seen a points distributor "stutter" the ignition signal when suddenly given +1000 rpm of immediate rev on my Sun machine and it gets worse if you use exceptionally light springs. Pertronix or EI distributors don't seem to have this problem (magnetic pickups).

-D.Idiot
Author:  Rust collector [ Sun Oct 16, 2011 4:46 pm ]
Post subject: 
Well, I have to say that a mopar ignition box works very well with the points in my 3.5hp lawnmower 8)
Author:  Reed [ Sun Oct 16, 2011 5:14 pm ]
Post subject: 
Olafla- I also have to question why someone would do this particular modification to the ignition system. I compliment you on your creative thinking, but the question then becomes why do it? If you want to keep your original points distributor, you can convert to a full point-less electronic ignition system by installing a Pertronix ignition system. Alternatively, you can install a full electronic ignition system without the wear point of points very simply and not too expensively.

It costs about the same to purchase a Pertronix kit as it does to purchase the components of a hybrid points distributor/electronic ignition module ignition system. It is actually easier to install a Pertronix kit, and only marginally more work to install a full electronic ignition system.

While the hybrid points distributor triggering an electronic ignition ECU ignition system can and does work, I would think it would be more of a curiosity than a desirable real-world modification. The only way I could see someone doing this is if they had absolutely no other options but already had the necessary parts.

I don't want to discourage you, but I just don't see the benefits of this particular modification when switching to a full electronic ignition system cost virtually the same and takes virtually the same amount of effort.


RustCollector- That thing got a Hemi?
Author:  Rust collector [ Sun Oct 16, 2011 5:19 pm ]
Post subject: 
:lol: :lol: :lol: Suure..... 8)

I think it is a flathead?...b&s, from the 70's some time.
It is my grandpa's old mower.
Anyway, it does work very well, but it runs on battery power, so... not perfect.
Author:  Danarchy [ Sun Oct 16, 2011 6:52 pm ]
Post subject: 
I really like the Pertronix ignition system, I have used it on other straight 6 engines(230 Tornado) with excellent results. I will install one on my Dart very soon. Is there some reason you wouldn't want to use Pertronix?

SlantSixDan- Do you wear a Belt with those Suspenders? :lol:
Author:  emsvitil [ Sun Oct 16, 2011 7:08 pm ]
Post subject: 
I've made the hybrid system of points and electronic for my old 72 mazda rx2 (rotary engine).

It actually worked pretty well as there wasn't a pertronix or other electronic distributor available.

For the electronic part, I took the cover off the ignition control box from a 76 toyota corona and copied the circuit and components.

The 76 toyota came from the factory with the hybrid points/electronic system...................
Author:  DusterIdiot [ Sun Oct 16, 2011 7:12 pm ]
Post subject:  Fine hairs
Quote:
Is there some reason you wouldn't want to use Pertronix?
Only one small one that would depend on your options for recurving the distributor...the EI spring posts are different than the points spring posts.
For the beginner, this isn't much of a worry...when you get into fine tuning the distributor's recurve the EI shaft with adjustable spring posts makes sense... The pertronix system is a pretty nice "plug and play" system to get rid of the points.

-D.Idiot
Author:  ceej [ Sun Oct 16, 2011 9:00 pm ]
Post subject: 
Hey Olafla,

I used a point system as a trigger for an MSD box, with five volts going to the points. It worked very well.

The points lasted for many years in that application. I installed them in 1993, I changed the points in 2002 when I gave the truck to Linda's dad. He had the truck until 2009 for a firewood hauler. He gave me the MSD box back when he got rid of the truck. To my knowledge he hadn't replaced the points, but I don't know for certain.

CJ
Author:  ceej [ Sun Oct 16, 2011 9:23 pm ]
Post subject: 
Probably should have outlined the reason for the hybrid installation..

It wasn't to make the points last longer.

The truck was a big Ford flat bed. It had a transplanted 390 that I built pretty heavily. (I'd blown the 352 to pieces, but that's another story.)
I had a big Crane hydaulic cam, small chamber heads, a Holley Street Master single plane and a 600 Double pumper installed on it. Headers, and big dual exhaust.
The balance of the build wasn't great. I had to install a truck pump, think 391, 534 and such. With the stock fuel pump I could drain the bowls as it wrapped up in third gear. Couldn't keep them full.
At around town speeds, I'd build up a lot of soot in the tail pipes. If I leaned it, I'd get surge and various driveability issues.
Installing the MSD box gave me a clean burn. It also helped a bit with the fuel economy. I got about 14 with the contraption when I didn't have my foot in it. Prior I was getting 8-9 mpg.

4.10 gears, 8x10 flat bed, and hauling all manner of goofy stuff. Even hauled a backhoe on the bed once. (Silly thing to do. Wasted the bearings in the Dana 60.)

Getting phenomenal life out of the points was an added benefit, and I didn't have to mess with converting to electronic. Before that I changed the points annually. The truck was my Daily Driver from 1988 to 1997. My dog went everywhere with me in that thing. :lol:

CJ
Author:  SlantSixDan [ Sun Oct 16, 2011 9:59 pm ]
Post subject: 
Quote:
Is there some reason you wouldn't want to use Pertronix?
I shy away from it because you can get higher ignition system performance with the HEI upgrade, and if a component fails you can get a replacement immediately, cheaply, and locally no matter where you are. If the Pertronix parts inside the distributor go bad, you're outta luck til replacements arrive from Pertronix. But this falls into the territory of deciding how much to worry about unlikely events; most people have found the Pertronix quite reliable.
Quote:
SlantSixDan- Do you wear a Belt with those Suspenders? :lol:
Yes, two of them. Image
Author:  emsvitil [ Sun Oct 16, 2011 11:39 pm ]
Post subject: 
My pertronix backup is a set of points and a condenser in the trunk........
Author:  Danarchy [ Mon Oct 17, 2011 7:31 am ]
Post subject: 
Quote:
Quote:
SlantSixDan- Do you wear a Belt with those Suspenders?


Yes, two of them.
Thanks Dan! You just made coffee come out of my nose! :lol: :lol: :lol:
Quote:
emsvitil-My pertronix backup is a set of points and a condenser in the trunk........

yes, I did the same thing, but they were in the glovebox!

Thanks,I will check into the HEI retrofit.
Author:  SlantSixDan [ Mon Oct 17, 2011 9:58 am ]
Post subject: 
Quote:
Thanks Dan! You just made coffee come out of my nose! :lol: :lol: :lol:
Yer supposed to drink it, not snort it! :shock:
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