Time for a Distributor Upgrade ???

[Toyz]

Loaf-a-matic, so no centrifugal advance. I should have caught that earlier! The advance is controlled by interaction between the springs and the vacuum diaphragm. The good news? It is "tinkerable"! by changing spring tension. The other news? With the mileage you are obtaining, I doubt there's much to be gained at the Load-a-matic.
Paul

[bobenhotep]

The good news is that the load o matic was only used on the 65 and 66 240. Any 300 or a 240 from 67 on will have weights. If you change out the distributor, you need to also change the carburetor to one without a spark valve. The carter YF 1 bbl is a favorite around here it seems. It is a good carb for economy, it has a fuel metering rod instead of an all or nothing power valve like some carbs. There is also a way to disable the spark valve if you keep the Autolite, but I have to look it up.

Dan

[ICEMAN6166]

But am I just adding unnecessary complexity to a simple truck

i think so.
points have left me stranded only once. a brand new set in fact, the contact on the arm fell off.
on the side of the box were the words "hecho en mexico"
next day when i returned them to the parts store and exchanged them for a made in USA set you could see the difference from the other end of the counter.
both were standard ignition, a quality brand.

[Toyz]

It's hard to beat simplicity. And points are simple. A Pertronix upgrade with a spare set of points in the tool box is hard to beat. But a new angle has recently revealed itself to me. A local wrecking yard has just informed me that a 1985 F-150 with a 300 I6 and electronic ignition came in, and I can have the entire ignition system for less that $50. Module, distributor, wiring harness, even plugs and secondary wires.
I looked up replacement parts for it and a module is less than $15 and a pickup coil $12. Almost cheaper than points and a condenser.
But am I just adding unnecessary complexity to a simple truck.
Now that she is running great, maybe I will just get a spare vacuum valve for the Load-a-matic.
But then I still have the original problem of backfiring while going down steep declines. Oh, I forgot to mention this. But I periodically take the coyote up to Kitt Peak Observatory (7000' elevation). Coming down the 12 mile service road, the truck backfires if left in second gear. I also have the problem that it jumps out of second gear when I do that, but that is the subject of a different post.
The backfiring is much reduced with the new pony carb, but I can't fully remove it. Now that I understand the Load-a-matic principle, I do think that a mechanical advance distributor would easily solve the problem.
But then I might as well upgrade the points to Pertronix (or some other brand). But then for one-third the price, I can install the 1985 F-150 ignition system
Aaagh! I just can't make the decision. Somebody (or something) else will have to make the decision for me. I guess I'll just keep driving all confused and blissful until the next item breaks.

At that price, I would upgrade! As you stated, replacement components are cheap and readily available. You no longer would have to be concerned about distributor wear; the electronic will give consistent dwell and more accurate timing, both items which can affect economy. This would also give you the opportunity to replace all components of the Load-a-matic as insurance against a failure involving increasingly hard to find parts. Electronics came about for multiple reasons, not the least of which was the then- forthcoming legislation forcing manufacturers to warrant any component which affected emissions. Modern systems do that quite well, thus have useful advantages, IMO.
Paul

[Oregoon]

I'd go with Dan's system for a direct bolt-in and some really easy wiring. Simple to work on, and replacement parts are readily available anywhere. All said and done, I spent about $200 on my conversion: New '71 Carter YF $120, '80 Duraspark II $60, and '80 GM four-pin HEI for $20.

I get a screaming deal on parts, so add maybe $100 more? I had some problems (unrealted to Dan's recepie) but after ironing everything out, my truck runs as well as my '94 F150 4.9 EFI ever did; perhaps even better.

[Toyz]

I agree with Dave as to Dan's system. However, I believe the '85 has the TFI system, very similar in concept. The only improvement I would suggest is to do like Dan and move the module off the distributor to a remote heat sink. It took Ford a few years to figure out that little improvement, but I'm convinced it's worth the effort. For $50.00, I don't believe you can go wrong keeping it all Ford.
I would consider the carburetor change-out if you can buy one right. The original can have the SCV eliminated; it just isn't near as efficient a carburetor in the opinion of many of us.
Paul

[Toyz]

I believe points will be around as long as you and I might need them, Doc! Yes, the Duraspark is obsolete, but I think replacements will remain available. The Loaf-a-matic? Not so much, IMO; limited OEM applications and un-popular system which has already been relegated to the trash can by many. If you are lucky and fail a bushing, that's workable. If the carb gets cranky, I suspect rebuild kits will still be available. Distributor cam fails; I suspect we will see a time that the junkyard is the only option.
A definite advantage to points; if they do fail, a quick inspection and a point file will often put you back on the road. A spare set of points and a condenser will cover the majority of times when repairing the old ones won't suffice.
In your case, with several spares and the patience and understanding to avoid early points failure, you may well be a candidate for remaining points-powered!
Paul

[bobenhotep]

This is my system if you want info on it. It is ugly, but works well. the whole thing fits in this picture. you don't have to worry about the plug on the distributor, because you cut it off anyway. You have to build a wire harness for it, but it has like 5 wires in the whole thing. If you can wire an electric car, this should be easy.




There is more info about it if you click the link in my signature block.

If you are still in the market for points, get a distributor for a 300. Pretty soon you will only be able to get load o matic parts by robbing museums. You can disable the spark valve on the carb, and it will work. The main problem with load-o-matic is not points, but timing. You will gain power and mileage with a conventional timed distributor. The electronic ignition thing is just a bonus. I personally don't like points, but only because I have a crazy extensive electrical background, and I was born after the points era.

Dan

[bobenhotep]

Sorry, this is without the tachometer.



There are 6 wires if you count the 12v power wire that hooks to the coil.

On HEI there is no resistor. It runs on unfiltered 12 volt power. there is also no wire going to the ignition solenoid. You literally hook a wire with a fuse in it directly to the ignition terminal on the keyswitch. I use a relay, but that is me.

wear on points is caused by the circuit shutting off and turning on to charge the coil. Some people don't know this, but the coil fires when you turn it off, not when you turn it on. The capacitor (which we call a condenser) keeps the points from violently arcing and wearing themselves out. This also limits how much power you can launch through a set of points.

on an electronic system like HEI or DuraSpark there is no arcing. The switch the coil on and off function is handled by the module, and it gets its commands from the pickup inside the distributor. All of the pickups work the same way, so the HEI module doesn't care if a chevy or nissan or a ford magnetic pick up is telling it what to do. Btw, what I was saying earlier about the coil firing when it is shut off, the coil is always hot when the engine is running. The points or the module turn the coil on by grounding it.

Anyway, the points aren't able to handle the brute force current the electronic modules can. Some people like points, they used them on cars for a really long time and the only bad thing they do in the long run is wobble from wear caused by the points pushing on the distributor shaft. The real bad guy in your situation is the vacuum only timing problem. The mech + vacuum points distributor is a good upgrade and is totally within the limits of what you are familiar with.

Dan

[Toyz]

Very good explanation. I might add that points can not easily maintain equal and maximized dwell. IMO, if you are not checking and setting dwell, you are not maximizing the system's potential. Even if you were to check point gap at every lobe, it still will vary in operation. As stated, a good set of points will have a tightly engineered spring tension, thus "pushing" a worn distributor's cam to the point that the actual running gap is less. This is where the dwell meter, or, better, a distributor machine, comes into use. A weaker spring or point damage will also result in "bounce" as described. A heavier spring will have reduced life due to the friction.
I fully expect the "I just set 'em and forget 'em" comments. In reality, most of us will do just that. Years of competition and access to some great (at the time) equipment tells me that is not the absolute correct answer.
Dan didn't touch on your coil question; a coil with compatible inner resistance is a good choice, but, IMO, not needed on a solid engine with correct plug gap and heat range.
Paul

[Toyz]

BTW, IMO, again, I would almost prefer the Loaf-a-matic to some of the Thermactor distributors. Almost!
Paul

[Toyz]

Hmmm, well, if the Pertronix saved you from another un-planned desert repair, it would be worth it IMO! Just like anything else, even the Pertronix may fail. They have a solid reputation for NOT failing, however, especially the Pertronix II. That is one of the big advantages to me; being able to stow away the removed points and condenser to have available for an easy re-install IF a desert failure should manifest itself.
Paul