Why so negative? Hey, big brother, no~ I shalt not fry my system. I am armed with the info Pat posted (somewhere). It reads like this: Wait! I have a positive-ground GMC, what do I do? This so easy, you'll kick yourself for not having figured it out on your own. All you have to do to convert that Jimmy to negative ground is: 1. Disconnect the battery (VERY important first step) 2. Reverse the wires on the coil 3. Reverse the wires on the ammeter 4. Reverse the battery cables. While you're at it, why not switch the ground cable from going to the frame to a starter mounting bolt or the transmission? It's better than the frame. 5. Put all your tools away and sweep the garage floor, because you are DONE. Oh, yeah. Power up the system to see if you did it right. Easy job. By the way, this method works for Fords, too (should you have one laying around). This may be the same thing that Big Tim posted~ I'll check that out next.
Zig, I don't know how to put captions with pictures but I think these are self explanatory. This particular bracket needed to be moved 1 1/4" forward which caused the rear ear on the bracket to interfere with one bracket to block mounting bolt so a spacer is used to move the rear ear out of the bolts way. The spacer (socket and washers) pictured is WAY too long but was used so the nut would tighten before the threads ended.
Thanks, Evan! Nice chrome alternator on an unpainted block! Thanks for taking the time to post those up! I just had to go and fool around with my setup. I put the generators pulley on my new alternator to keep the wide belt. I flipped the generators mounting bracket that bolts right above the oil pan. This moved the whole works out perfectly in line with the other pulleys. The top bracket had been "modified" by someone with a welder and who must have been enjoying adult beverages~ I was able to cut off some of what he had put on, then took it to my dad's grinder. It now looks much better, and should work fine whenever I get the two flathead screws out of the back of my water pump. I want to replace the gasket there, but you know how well it works to stick a screwdriver in the slot of a screw that hasn't been turned for ...ever... Once I get those out and the pump back on, I can finish hooking up my alternator! I'll post up some pictures to show how it worked out. Thanks for the help and ideas, Evan!
Alternator Bracket This is what I did too ~ I simply flipped the old 6 volt generator bracket 180° and drilled one new hole , then I got a long bolt and some shims , you can use a bit of water pipe or steel tube, trimmed as needed to make a cleaner looking spacer , me I had free washers by the boxfull so.... a typical Farm Fix I know but it's been trouble free (! and FREE!) for many years & miles now . Didja notice ? the old generator in those pix had a cutout on it , this means it's prolly a three bush one....
My fix~ Here is how it all played out. First, flipping the original generator bracket put the bottom of the alternator right where it needed to be! ~cool~ Next, I cut down and ground edges of the (very rough) homemade bracket. Painted gold, it didn't look toooo bad. (especially if you squint your eyes and cross them just a bit...) I could tell the mount needed to be bumped out, so three washers did the trick. Nice and lined up, and the homemade bracket had just the right amount of space to get the belt "just right" tension wise. Now if I can get my fittings fitting again.
Zig: I'm concerned that that alternator will bounce around quite a bit when running. It will try to twist in the two bolts you have supporting it. It'd be a lot more stable if you turned it over with the wide mount on the bottom and then had a long bolt (or all thread) going through both ears of the mount and the long hole through the alternator case. That would cut way down on twisting. Either that, or put some sun screen on it ....
I agree Zig, as soon as that thing is under a lode it will twist, it needs some support at the back end.....Big Tim Scratch that Zig, after looking again it appears that you have the Alt. upside down. Just roll it over and run a long bolt with spacers all the way through the lower mount and you will be fine. The threaded boss on the Alt. is your adjuster and the big boss is the part that go's down on your lower mount.
At the risk of sounding redundant, I agree w/ Bill and Tim. You need to make the bottom part more "fixed" and less prone to twisting. One long bolt thru the bracket and alt. would be the fix with the top bolt used to adjust the belt tension. With that, I think you're there!
Uh, yup~ That makes sense! That's why I love you guys~ HOWEVER~ Upon further review, that beefed up upper arm takes flex out of the question. It just doesn't have play. It may have been a homemade hack job of welding, but given the thickness of metal, and the short length of that arm, it seems like it should work. Time will tell. Thanks for trying to keep me lined out! Lord knows that's a tough thing to do!
Paulie NO ! You're going to snap off the adjuster ear of that 100 Ampere alternator ! trust us ! . Flip it 180* and get the long bolt & spacer or washers I referred to else you'll be crying in your beer soon .
Okay~ I went out and flipped it to see how things would work out. The problem with this is, the adjusting ear needs about a 14", very curved, adjusting arm. I posted the head-on picture again so you guys can see what I mean, as far as how far out there the adjusting pin would be. The shortness of the beefed up (homemade jobby) really doesn't allow movement. I grabbed the ass end of the alternator (it did nothing for me, by the way) and pushed and pulled (quickly, and with force) toward the engine and back out to the side and got practically no wiggle. If there were any more strain than that, I would think the bearings will be shot in no time.
Adjuster Looks to be on the wrong bolt to me , the fan blocks the pic but I know mine isn't steeply angled like that .
Zig I've been studying your pix and here's what I think, This is my professional opinion as a fabricator with 30 years in the trades. 1St. Go buy a Chevy and start over I'm just kidding Zig, what I really think is the Alt. is mounted too low. I think there should be the same lower bracket only with longer ears so that the Alt. sits high enough that the threaded boss on top of the Alt is level with the water pump mounting hole that you are using for the top adjuster bracket. 2Nd. you really need to use a long bolt with spacers on the bottom mount that catches both holes because what will happen is the vibration will eventually make the one mounting ear start to crack and with a long bolt and catching both mounting holes you will eliminate the vibration that will make it crack. 3Rd I think if you use a small block Chevy slotted Adj. bracket you will be able to cut it to length and drill the end and you will have a better looking and more functional bracket. By doing all of this you will also have more belt riding on the lower pulley. I hope this helps....Big Tim
Vibration???? See~ THAT'S the problem! You guys are worried about vibration causing problems, but don't forget- That's a 228 l-o-n-g, block *GMC*! Vibration????? Thanks, Big Tim. I _will_ take out the bolt and put in the all thread that will pass all the way through the lower bracket. I will also put a couple of the largest washers (fender?) that I can put behind that ear. (Backed up with a nut, of course...) This is a good idea, and I appreciate it! Now, what the heck is a "small block Chevy slotted Adj. bracket"?
original I was just going with how the generator was installed originally. (Using the same mounts/brackets.) The homemade job that I cut down actually was about three inches longer, but was still at (roughly) this same incline.
Zig ,the small block Chevy slotted bracket is nothing more than a piece of curved flat bar with a slot in it. If you get a piece of flat bar 1"x 3/16" and drill a couple of 3/8" !n. holes in it about 6"In. apart then take a cut off wheel and cut the slot you can make one. I would do the same thing with the lower bracket, duplicate it only make the ears on the end longer which would raise the Alt. up. Just make sure you drill all of your holes before you bend the ends, it's easier that way.....Big Tim
Here's the small block Chevy Alt.bracket I'm talking about Zig, (67-72 Chevy truck) I think it could possibly be cut and modified to work for you.
That's it! That long assed arm looks like it would be _perfect_! I need to get one ASAP and flip my alternator around (like it should be) and see if it will work. I absolutely would need one that long. Could you measure what the length is on that one from anchor bolt to adjusting bolt on that alternator? I'd give you a big, manly hug if you could!
