Geoff Weeks

Just put on and fire it up. It doesn't fill with oil, oil is pressureized into the crank, which lubes the rod and mains , oil then drains back to the engine sump.

Not so far in left, it depends on how well the regulator can clamp a light load. Normally, alternators of this size came about after the electronic regulators. Smaller output units, the battery can stabilize the highs and lows, Mechanical regs were primarily used when cars had 37- 45 amp units and trucks were no bigger than 60 amps. 100 amps, with a mechanical reg and resistor cards, were rare. I have not had the 100 amp 6 volt unit up and running on a vehicle so I don't know how well it clamps the voltage on a light load. That said 18 volts is way above the 14- 14.2 set point. I would expect it to be able to clamp better than that. A short in the field lead could burn a resistor card in the regulator and permanently damage the regulator. Finding replacement resistors would be hard. All that said, I wouldn't want the selenium rectifiers. That is what holding mine up/ I want to replace with modern diodes. Modern L/N diode packs would work well, but need to be cooled, so I need to fit them, isolated from case, in the air intakes on the back so cooling air gets drawn over the diodes. Just getting the time to get it done.

Bet on it. 700 cid would be a whole lot of hurt if it came apart.

In case anyone cares: Here is my 100 amp 6 volt unit, a bit different from his 100 amp 12 volt regulator. Output from the alternator is 3 phase delta wound stator. A three phase bridge rectifier that is isolated from the trucks wiring when the engine is off, via the big relay under the reg cover. On mine the voltage regulator controls the hot side of the field, but the alternator itself could be regulated by either hot or ground side. Note the grounding tab on the last picture to ground the rubber mounted regulator (common at the time to isolate the reg from the truck to reduce vibration induced problems. Rectifier is isolated when the truck is off to prevent leakage back through the windings and for safety, in case something falls on the rectifier when someone is working on the engine. Mine came from a 40's GMC tow truck.

Yeah, but a threaded pin does nothing to help remove the bushing, hanger still has to come out to replace the bushing if you don't have access.

Be aware the Selenium rectifiers used can "pop" releasing toxic vapor, which is why, I am looking to replace mine with modern diodes. https://en.wikipedia.org/wiki/Selenium_rectifier See above for more info

Interesting but a few things wrong. the KT was no longer than the 855, a bit taller and a whole lot heavier. it was one of the reasons for the weird fan drive, to keep the same envelope as the 855. I used to work at a place that rebuilt them for construction equipment. The main thing was that it was an inline, easier to fit between the frame rails that the big V engines. My IHC 9670 were fitted with 1500 sq" rad and could go up to 1800, so yeah 2000 was big

Paul, Early alternator systems (talking 40's and 50's) had the rectifiers mounted separate a they didn't have high power diodes at that time. Remember, this is a time when most semi trucks had 50 amp generators. Fire trucks, and tow trucks could be fitted (at great expense) with L/N's alternators, Not only did they provide much more current, but could do so at lower speeds. Important for E vehicles. I have a 6 volt 100 amp set-up that is similar to the one here but not exact. Because the rectifiers were external, they were not kept connected to the battery like a modern alternator. The big regulator had a main relay inside that closed when the ign was turned on, and also a voltage regulator. (current regulation is not needed on an alternator as the winding are self regulating). The rectifiers have nothing to do with shop power, they are for the engine alternator. For some special application remote rectifiers are still used. My unit has the same rectifier set up. If he just wants to "get it running" then the whole system can be replaced by a modern (one wire) alternator. Alternators DO NOT get polarized, and in most cases generators don't lose there polarity, so only need to be polarized when a new unit is placed in service or an old unit is used on a different ground vehicle. Some fire trucks used the 3 phase output via transformers to provide 120 volt power for lights and universal motors for saws and the like. I'll have to look at my regulator and see if it is enough similar to his to be sure of the connections. Fairly sure the problem will come down to voltage drop in one of the circuits, either the ground or power side, or the field not being fed from the regulator like it should be, but cross shorted to the output wires some how. Without either being there or good photo's I can't tell what the problem is. Part of what sent this down the wrong road was saying it was a generator, that lead to the whole polarizing issue which has nothing to do with this. On the 1st thread started, I mentioned it might be an alternator and asked for pictures, which were not provided at that time.

Yes, that is a rectifier. and so it does have an early alternator system. Not a generator (dynamo). Yes, as I stated before, it could have a bad connection between the generator and regulator. Body could have a bad ground between it and the chassie, or frame. Technically, anything that produces DC is a generator, while anything that produces A/C is an alternator. But in automotive terms the two get mixed up a bit.

OK, this is going to be hard to sort out. It isn't the typical truck charging system, it is firetruck special. Not having the schematic on hand this is what I can say B goes to the ammeter or battery F to field Gen to armature ign to switched ign feed You didn't mention the terminal at the top G may or may not be ground A regulator is only as good as its connection to what it is regulating. If it is not making good connections it can't regulate. I still want a pic of the generator and associated wiring, it may still be an alternator, as I have a L/N set-up that looks very similar. You really are going to need someone who knows this type of equipment. Most truck people have no clue. With the ign feed, I suspect this is an alternator set-up with remote rectifier (big finned thing with three heavy wires coming from the "generator" and one heavy wire to to regulator) The early remote rectifier systems are weird in that the regulator dis connects them from the battery when the ign is off. This is how mine is set-up, it is similar but not exactly the same. It is a 100 amp L/N 6 volt alternator from the 50's. More pictures are needed.

BTW this is the 2nd thread on the same problem in the same section. don't start multiple threads on the same problem it gets confusing.

that said, polarizing will have no effect on the voltage setting. SO either you have a wiring problem, a regulator problem or a grounding problem. A regulator can only act on the voltage it "sees" so if the ground path is poor, it will "see" less voltage. I may be wrong, but didn't most have Delco generators? Lets get a picture of what you are working on.

Battery to Armature. Not to field. If in doubt, connect a jumper cable to the battery hot and touch the other end to the heavier of the two terminals on the genny.

I've got two sets but three engines for two trucks. So I am in no rush either. Here is another that show the contents https://www.mechanicsurplus.com/products/5698909517 Quite a jump in price, however. Think on it, the seller will not be around for a week. If by next weekend you still don't want it, I will likely decide its cheap enough to have on hand. Gasket sets and main bearing are the hardest thing to find for these engines. Oddly oil pumps seam to come up often either complete or kits. When I find cheap spares, I often get them. Finding some when you have a need can be hard and expensive.

One of us should jump on this: Only a head set but still https://www.ebay.com/itm/313126024114 I'll give you 1st refusal, if you decide you don't want or need it, I might grab it.

I think they were primed with Gasola or other orangish sealing primer and then a blue green top coat. Black for accessories. The lower left side of the block seams to be about the factory color. I think there are people re-popping the Donaldson air-cleaner decals. I think Jeep and/or Powerwagon used them.

Depends on how worn! 😄

20 years ago you could still get gasket kits, but no more. I suspect custom gaskets are going to be your only choice. Be sure to get the one between manifolds, as 'm sure you know, they have to bolted to the head with that connection loose, only tightened after the "assembly" is firmly attached to the head. Be sure not to loose the two "locating" ring in the intake manifold. Notice the "fuel pump" opening on the right side under the generator mount? That is a hold over from when there was a gear driven generator/distributor or Mag on the earliest engines. Victor set FS3031 would be the set, but it is for the bigger 282-308 really, works for the 269 also but as I say, NLA. Might find one NOS though.

Supposedly the pro's of threaded pins is it increases the surface area and grease contained. I never liked them myself. Plain pin in a bronze bushing, replace when worn is my choice.

???

My white one, the cab is so far gone that the upper cab is loose from the lower (supposed to be welded together) I have another cab for that one. The winch truck is as close to "all original" as one can get. The wire type used in that period deteriorates over time, and making new is the best way, eps if you can get it out in one piece and copy. You have the choice of modern wire or modern wire that has an older looking fabric outside for period look. I have never done the matching numbers/colors wire type "restore" but my hats off to those that do.

Clean looking for its age.

Can't hurt, air tool oil, but I never did.

Best thing that can help is a picture of the rear end from the front, any casting numbers you find on the drop-out (center section, hogs head, pig or what ever slang is in use in your area) and same for the transmission. We need to ID these two items in order to see what can replace the current gear sets with the least amount of changes. A check on line of the Mack model numbers leads nowhere for either the trans or the rear. If you are lucky, Mack didn't make them, but bought a vendor supplied unit, and we have to figure out who that was and what they call that model.

Trailering might be the cheapest way to go. If distances are long the fuel bill is going to be big even if you could drive it. I spent some time looking through a diff catalog. There are less that 1/2 dozen front loading diffs with a 5.13 ratio. SO if it is front loading AND we get some pictures, we MIGHT be able to find out if there are other options. Trans change is likely going to be part of the equation also, with that come possible bell housing and most likely driveshaft changes. All would be hidden underneath and would look stock from the outside. I agree I wouldn't want to cut up something like that, and things like tread width can vary leaving you with an axle that sticks out too far if the whole rear is changed. Any change is going to a an expensive undertaking, but knowing what might be possible will help make the choice of what to do easier.