Hot engine won't start?

Do you have a mechanical tachometer that you can actually measure the alternator RPM ?

That is a really good resource I wasn't aware of. This one might work........

That assumes 17mm is same as 0.625 diameter shaft on alternator. The math isn't exact, but close. Frustrating that they have to mix apples and oranges (SAE and metric) to to make it more confusing.

Past that........the plot thickens........meaning my education on all this continues. This from Powermaster (whose material is both excellent and abysmal).........

Edit: Measured and it's 6.25" / 2.65 = 2.358  (better than I feared, but still not good)

I'll have to measure, but my guess is OD of big pulley is no more than 5 inches.....turning a pulley of about 2 3/4"......so ratio is not much more than 2:1. At engine RPM of 1,000 fast idle speed, even this high amp alternator is not putting out much juice. Even in use in the field, engine rarely exceeds 2,000 RPM's.  Documentation that came with alternator shows it tested to 65 amps at idle speed, but that was with 3:1 ratio. At my idle speed, may not be doing much at all. 

So a lot of this then goes to operation. If working at night and are moving from field to barn.......and back........best let the engine rev......(do not shift up)......to get RPM's to 2,500 or more for as long as you can. Alternator really isn't doing much unless you do. 

All part of the puzzle. 

X2 on the high riding belt. Looks like a B belt in an A pulley...

Bolt circled in green was the culprit that started all the trouble. It runs thru tensioning bracket, mounting bracket, cast iron water pump, aluminum timing cover, then into threads in cast block, but also terminates with end exposed to engine coolant. 

Bolt circled in red ends in a blind pocket in the engine block. It is the main support for the alternator. When tightening belts, tendency may be to loosen the problem child bolt too, but if you do, that would break the seal on the thread sealant......maybe now a leak.  One just has to remember to never, ever touch that bolt. The bolt in red and tightning screw on the alternator......and nothing else. 

Have given thought all manner of fixes.......everything from a hard plastic bolt.....some sort of ceramic coating, etc. Cheap and easy might be to butter it up with Anti-Seize before installing. Once installed, this one bolt would be the only one of several that would ever have to turn. It is one of three that is used to hold alternator bracket on, but this one also does double duty, being lower anchor point for the arm used to adjust fan belt tension on alternator. Anytime the fan is adjusted, or to replace the belt, that bolt has to turn. Somewhere along the line somebody tried and broke it. 

And again, it does extend into the block where end is exposed to coolant. Some design engineer screwed the pooch on this one. 

Cover is off (and it wasn't easy) and broken bolt is finally out. Had to hack up the cover and once inside was very plain to see, corrosion to the bolt was holding it on. No amount of heat or soaking was going to free it up. Had to go postal on it. Once cover was off, the bolt backed out easy with vice grips. 

Once inside, looks to me like timing chain is suspect. Good amount of slack in it. If going to replace, no time like the present. 

Widely believed the Deweze version (this one) left factory with engine, tranny, front and rear axles same as Dodge D600. The rest was fabricated and grafted on. Spoke to the young man I bought this from and he replaced the original factory engine with a used 318 engine sourced from a salvage yard.  He had no idea what it came out of. It has an odd casting number.........xxxxxx-318-16. The 16 part is where numbers vary depending on use. Nobody seems to know what a 318-16 was intended for. Aside from cars and trucks, we know they were used in a whole slew of military vehicles, RV's, boats, irrigation pumps, Oliver combines and who knows what else. Some floating around were just spare crate engines, which is what this one may have been. 

The MOPAR guys gas on about cams, headers, carbs, etc., with most of them interested in high RPM horsepower and if it will hold together above 6,000 RPM long enough to smoke the tires off. At other end of the spectrum would have been that Dodge D600 truck. High torque at low RPM's not intended for high road speed. (Not a muscle car). Carb, headers, cam shaft all optimized for that use. That would be ideal for this rig, but not sure how close it matches......if at all.  It does have same NP 540 transmission, but only single speed rear axle.  So the geared way down, high torque setup. 

If i was to go on a hunt to replace engine, I'd be looking for a donor from some form of Dodge D600 truck. Actually have a line on one in form of an old firetruck, which is sitting in a salvage yard. Some of these D600 trucks were retired with less than 30,000 actual miles.