Geoff Weeks

A word to the wise, make the mount 2x-3x more stout then you think it needs to be. Delco recommends 3/8" plate for making mounts. I found that it needs to be at least that thick and firmly mounted to the engine to prevent it from breaking. As I stated earlier, you can keep that rebuilt generator as is and it will do the job just fine.

Ok, I am mixing up two people with old Red Macks with Cummins in them! I have Big Cam mounts that are yours for the postage but don't think it will work with your set-up

I might have a Big Cam alternator mount. what does your big cam have on the front of the engine. Big Cam 3 should have duel belt sheeves behind the damper for alternator drive. am I mixing you up with another guy who has a Big Cam 3 and you have an old Cummins?

https://www.shopzorkos.com/Category/5116T this is close to what I had. The one I had bolted directly to the back of the alternator, this one is remote.

Those large case generators aren't that common anymore, and in my mind are of value. I have 2 12 volt and 1 6 volt so don't need more. If it were I, I'd keep the generator (period correct and 50 amps is plenty) as it will work just as well on either polarity. But that is just me.

yes. Both Delco and Leece Neville used to make duel output alternators that would allow you to eliminate the Series/Parallel and keep 24 volt cranking and 12 volt for everything else. The Delco is still available (Delco 30SI-TR) but I only see it in negative ground. 40 years ago I had the part to convert that JB2500 to the same, but it is long gone. I haven't seen the JB kit since I had the one I had. Series parallel seams to "throw" people as bad or worse than positive ground. https://smithcoelectric.com/products/240-821-new-alternator-for-delco-30si-12v-90a-with-24v-transformer

You are 100% correct the case is neutral on the JB series. so the positive goes to the frame on a + ground truck and the negative goes to the truck wiring. The internal voltage regulator doesn't care as it is isolated from the alternator frame and gets its power from the + and - stud on the alternator itself.

BTW is Dennis Kirk gone? I have a few of the older catalogs but haven't tried to find them on the web.

But think of the enjoyment reading those catalogs and dreaming about what we would get when we had enough coin saved! In some ways looking for parts for these older trucks is as much a treasure hunt as it was in the old days sending off and waiting for weeks for the parts to come.

Thank-you but I am just passing on what I learned with my own truck. Might be worth throwing some plastic gauge on the bearing while the pan is down. Bearings show up every once an a great while on E pay. The mains seam harder to find then the rods for some reason. If yours are ok but on the high side, better to have time to find them. I think Egge can supply them, or could but they are proud of them, for sure.

Let us know how it turns out. I will freely admit I have more to learn on motors and how the current flows in them. simple 2 pole generators or motors it really only can have one flow path. I am less sure when it comes to 4 pole esp with how the windings are on the armature.

Unless it has been rebuilt, that is 80 years of accumulation in there. Likely most of it with non-detergent oil, which allows the heavy stuff to settle out.

That light gauge wire is enough to balance any slight difference in the current through the paired coil path, but I don't think it is heavy enough to carry a full 1/2 of the current draw of the starter. Yes, mine have that wire also. I don't remember what gauge it is, something like 14 or maybe 12 at the most. Like I said, I don't know what is going with those coils, they are NOT the same as the stock set-up. I am just guessing here, but I wonder if for 12 volt they ran all the coils in series, but in that case there should be a large conductor tying the two "hot" brushes together, the same size as the series coil stock itself. That little wire can not carry that kind of current. All I can tell you for sure, is that is not how the stock motor is set-up. If you can, bolt the pan back up and run it for a few hours to flush more gunk out of the block, use RTV or the old gasket so you don't waste a new gasket until the final time the pan goes up. I was surprised by how much more stuff came out after the 1st cleaning.

Got curious so looked it up, according to my manual for the 1973, slippery road reduces the pressure to the steer brakes by 50% , so a 30 psi at the treadle would result in 15 psi at the front brake chambers.

The wet/dry road didn't "kill" the front brakes, it reduced the pressure provided to the front by a percent of brake pressure in the system. I don't remember the exact percent, but my '73 and '69 had the manual valve on the dash and a "ratio" valve before the front brakes. Modern trucks have the same thing but is automatic will provide full pressure if the brake pressure rises above a set pressure (60 psi?) and on lighter braking reduces brake pressure to the steer. That is different from when no steer axle brakes, where brakes were not fitted on the hub. Driving a bobtail tractor with no front brakes on the axle on slick roads is a real pucker factor experience. Over the years different things were tried to address the front brake issue. Before the dry/slick manual controlled valve, smaller chambers on the steer (today type 20 is the most common) but that limited braking on dry roads. No front brakes, Larger chambers and either driver selected or automatic limiting pressure were tried. Today automatic reducing valve and large chambers are what is used to meet braking stopping distance requirements, where standards dictate stopping distance loaded and loaded with 1/2 the system inop. Front brakes that can deliver maximum braking force on the steer are the only way to meet these requirements.