50DN alternator

[chessie4905]

   Take a heat gun and check the temp of an air cooled 50dn after running 4 to 6 hours under half load in the engine compartment and compare it to a gear drive oil cooled one. Even little air cooled ones working hard can get very hot. They aren't that leak prone, however the engines blow so much leakage mist from the fan that it looks like everything is leaking.

[luvrbus]

I have checked the temps between the 2 Chessie big difference with the air cooled on a Eagle with the separate air intake for the 50D than a oil cooled on a GM

[chessie4905]

   I still doubt that operating temp on an oil cooled one is any issue, but you are a little Eagle biased anyway as I am to GMC's so I'll let this one be.
  On our 4104, after a great deal of over or under charge issues, even with several adjustments using the factory repair manual  over a couple of years with the direct drive generator 180 amp unit, we removed it and installed a 160 amp re manufactured Leece Neville, we purchased from an electrical rebuilder. We made custom brackets, installed a dual pulley drive adapter to the direct drive location on the engine rear housing, and hooked it up. It had a little voltage adjustment screw on it, which we set once the batteries were full, and never touched it again for 150,000 miles; changed belts once. The main mount  was on the engine housing where the trans mounts. I think we might still have the cardboard pattern. The mounting was compact, substantial, and professional looking. The gap between drive and driven pulleys was about 4 to 6 inches when properly adjusted. No direct outside air intake. We bolted the two large regulator lug leads together, and only used one or two of the remaining smaller wires. Connected the big main lug from the generator to the new alternator. Btw,the dual pulley drive came out of an old International cabover with a 6-71 DDA engine.
   Removing old generator and regulator probably saved 50 lbs and improved fuel mileage by at least 5 or 10 miles to the gallon.......

[luvrbus]

I do like Eagles but I fell about the 50D like you do about grease vs oil for hubs JMO belt drives and air cooled are just better

[chessie4905]

   Also, converting to a belt drive 50dn on a GMC would be somewhat of a pita.

[LuckyChow]

Our property tested a half dozen Delco 50DN knockoff's last year.  These were direct replacements for the Delco, but were a different manufacturer.  They were belt driven, like you find on Series 50 & 60 engines.  Our results were not good.  We experienced very early failures.