Hi all,

As some of you may have read, I blew my alternator this week. It had been weak for some time, and the addition of electric fuel pump and rad fan were far too much for it to handle.

First and foremost, thanks to Paul T., whose site, http://www.teglerizer.com/alternator/ was a BIG, big help. I have largely followed his procedures.

But, the Midget 1500 is apparently not exactly the same as the Spitfire 1500. So a couple of little gotchas on the way. Here's how I did...

First things first, disconnect the battery. I painted this last year, but the battery acid has done its work. I'll redo it with POR, topcoat it and add a battery 'blanket' to avoid having to do it again.



Here's the crappy old Lucas. 30-something amps when new, definitely not up to the task. Out it comes.



And here it sits next to its replacement. I went to my local parts place, and (true to form) they weren't able, at first, to find anything using 7127 (-9, or anything else.) "Fine" says I, "I have a... umm... 1974 Chevy Nova, 350, no A/C." Parts Guy calls it up on his trusty computer. "Alternator" it says, "7127-9". Parts Guy looks sheepish, and wanders off to find same.

There are many brands, all with slight variations. This one, a Champion rebuild, is 65A, and cost about $100 with the core charge.



The 7129 has two mounting 'ears' - a thin one, threaded, and a thick one, not threaded. I ended up using the thin one as my bottom mount, and the thick one as my top mount.

Now, here comes probably the biggest difference between the Spit 1500 and Midget. Where Paul's page shows a spacer at the lower mount, my 1500 had the alternator mount (attached to the block) with a long solid tube, no spacer.

First, I drilled the threaded hole of the thin mount out to 5/16ths, the thickness of both the mount bolts.



Paul's page mentions shaving down the thin ear slightly, and I did, but with the thicker alternator mount, it's not possible to line up all three pulleys just by shaving the alt. It's too far out (forward). The important distance is centre of pulley to rear of mounting tab, and I think the two were about 3/8 different.

What I did in the end, and what I would suggest anyone else do *instead* of modifying their alternator, is take a zip disk on your angle grinder, and take off maybe 3/8" or 1/2" off the front of the lower mount. Take off slightly too much, and then shim with washers; it's easier than trying to shave off 'just enough'. the mount is still long enough that there is little to no wobble. That's what I ended up doing, but with and eighth or two off the ear as well.



The bolts I'm using are all 5/16ths, but my local hardware store didn't have long bolts in UNF, so the lower bolt is coarse thread. Lower bolt has a nylock nut, since it has to be left just a tiny bit looser (to allow movement). I need to either find a 1/4" shorter bolt, or hack some off this one, as it *just* touches the drive belt when installed.



The top was almost easier. As with Paul's site, I hammered a piece of scrap sheet metal around a 5/16ths bolt, to make a spring pin, which I knocked into the upper mounting ear. Fit great first time.



I kept the original alt bracket in place, and turned it up all the way to remove any play. My NAPA store had only one alt bracket in stock, and thankfully it fit beautifully. Drilled a 5/16ths hole in it after test-fitting. Attached it to the existing bracket, and it stood about 3/16ths proud of the alternator, which was taken up by a couple of fender washers.



Continued below...

Wiring was as described, and even my Parts Guy was able to find the generic pigtail.



The natural orientation was for the wires to feed out the side, which was perfect. Mounted any other way, the rear case can be rotated (so the wires aren't jammed between the alt and the engine block, for example.)



So there it sits. Took a good few hours, factoring in extra runs to the store, and the occasional libation. The battery tray is covered in POR15 as we speak, so it will have to wait until tomorrow before I can confirm whether all is well.



Once I'm sure it's all OK, I'll rewire my fuel pump with a relay, and figure out why I've got a stumble in my ignition (if it's still there. Could have been a result of either the alt or the pump's drain on the ignition circuit, I suppose.)

Phew!

thanks for the update - looks great - that's one for the wiki - cause I may need it!

Duncan,
Thats an upgrade I performed a few years back. The difference is pretty amazing when it comes to the brightness of the lights and such. I ended up with the 12o'clock position variety. I didn't know the rear could be spun. I'll have to try that. Also, I ended up shaving more of the bracket but I used the thin mount at the top and the fat mount at the bottom. I've put too many of them into old chevy's to consider mounting it upside down till you showed us how...lol.
Thanks for the input,
JC

JC,

Have a look at the Teglerizer site. He explains 'clocking' the case, and how to do it without wrecking the brushes!

Time to stick the battery back in and fire it up...

Oh! The large black bolt on the back of the alt. Do I need to install a seperate ground for this? I have to imagine the case is pretty well grounded, with how it's mounted and all.

Charging at 14.4A at idle. Everything seems to be working great!

Wow, neat job, neat write up. Do put it in the Wiwi.

Thanks Jack! Hmm, I might have to go for a drive tonight, just so I can try out the new & improved headlights!

Duncan - you've likely read elsewhere that I'm having alternator problems - if I have to go this route, could you explain the wiring better. Mine has 3 wires - your harness appears to have 2. also, dis you splice it in?

thanks

Duncan, good work, looks nice.

Might I suggest one thing.

Most cars have three mounting points for the generator. Even the Delco uses three mounting points, though only two bolts. On your installation, the long mounting flange is only attatched at the front end. Therefore only two mounting points. This is usually fine for a starter, which mounts onto a large flange, but the generator is free to vibrate. And excessive vibration can break one of the mounts (the smaller one probably).

What I propose to suggest is a brace at the rear of the generator to the block or head to help prevent vibrations. I know it would be a real pain to install, but you really wouldn't want your new very nice looking generator to break the lower flange off.

Good point, but it's hard to see a way to do this. Maybe just making the upper bracket stiffer?

I made an offset bracket from steel tabs when I put a Delco on my 1500. Sort of like this.

Rather than "clock" the case there are different 7127 alternators with different positions. Here's a link I found, scroll down the page, even tells you what car, model, etc to specify when you order.
alternators

This is one upgrade I plan to do, great info!

Thanks,
Bud

and which one would be for the 1275 midgets?

This might help...
1275

Bump - can someone still explain this? My weekend project is the conversion. If you go to two wire, do you loose the light on the dash? does it plug directly into the existing harness or do you have to adapt?

JP,

I will do my very, very best to take some pictures of my conversion Saturday afternoon if you can wait. No offense to Duncan's fine work, but I think my way of doing this may be a bit easier, and by the looks of your alternator, more compatible with the mounts in your car. I *think* that the alternator mounts changed from the early 1500's to the late. If you get a chance, snap a pic of the lower alternator mount and send it to me. Once I see that, I will no for sure if my way of doing this job will work for you.

I'm mortally offended!



Hehe... Are you doing something similar to what Donn showed on the previous page? That's how I'm going to have to do mine... It's worked fine, but when revving the engine I can see a little bit of flex, so I'd rather be safe than sorry.

sorry to break your heart

actually was telling a friend last night how cool it was that a number of us were doing this conversion at the same time. She was surprised and impressed to know that not only were we relying on the help of friends worldwide to restore the cars but we were also building the body of knowledge by sharing what worked. This was a cool concept for her. And once again let me say how much I need and appreciate this board.

OK niceties over. Let me get this straight

I need

1 alternator model 10SI / 63amps / clocked 9:00 AC/Delco #321-41 / Lester# 7127-9 (this from http://www.madelectrical.com/electricaltech/delcoremy.shtml )

2 metal tabs and bolts to attach to lower bracket as per Donn's diagram

1 J-bracket for mounting on the top

1 new harness end

beer

am I missing anything?

Oh, and do you think aluminum would work for the the lower brackets?