Another alternator question

I bought a rebuilt alternator for the 911 engine in my speedy (the clean one) to replace the existing one (the dirty one). Both are supposed to be for early 911's and both are 55 amp but the wiring is very different. Some I can tell like D- is stanped on both. But there's no letter or number on the single spade terminal on the new one nor are there any legible letters or numbers on the two spade terminals on the old one...both of which had wiring to them.

Anyone know if and how these are interchangable?

Brian, I wish I could remember what mine looks like and/or to help you.

I have an early 911 55 amp alternator in my Spyder. A local friend had an electrical shop a few years ago(2003-4). He converted mine, which was an external regulator. A small Japanese regulator is bolted to the backside, the wires from it run inside to the windings/brushes.The regulator is about 1 1/2 by 2 1/2 by about 3/4 inch deep in a metal box, I don't know what it is off of, but it works flawlessly, charges at 13.9 or so.

Anybody else know?

Hi Brian, First "I don't know from previous experience with 911 alt's" but if the physical case is the same you are half way there. You just have to find out if they are internally or internally externally regulated. With that info you can make the charging, indication connections or adapt a nice (jap)solid state regulator (like above). Volvo makes a nice one too.

Bonus find----(does this help???)-

http://forums.pelicanparts.com/showthread.php?t=401341

Perfect Bruce! I looked on Pelican first but couldn't find it. Probably searched for the wrong thing.

They were all externally regulated until 1982 wherin they switched to the internal ones. I think there's three versions of the old ones, Valeo, Marchal and Bosch if memory serves. Actually, one of the valeo's might have been internal but maybe the one I'm thinking of was converted to internal.

As long as the depth is the same, they'll work (as noted above). There are differences in the little nut for the shaft though, so don't lose the one you have/need. You can internally regulate any of them with a good electrical shop. Also, give a local shop a chance to rebuild anything you have so that you avoid the porsche tax. Parts is parts.

The depth is the big thing. I was going to swap my 82 alternator that needed a rebuild for a freshly built 85. The 85 was taller and pushed the cooling fan out too far... Visibly wrong when I put tried putting it together - LOL!

angela

Thanks Angela, I'll have to check that. I haven't driven my car in two years and I'm determined to get it back on the road this year.

Brian - how long will you have to wait to actually SEE the road (i.e. the snow has melted)? Yellowknife actualy shows up on my morning paper's weather map. Looks like you're closer to Russia than to California.

Road is starting to peak out now but then so are the pot holes.
Got some huge ones that my speedy could not make it past. Problem is they don't plow the roads but spread gravel on it so now the roads are basically gravel roads until it totally clears and they sweep up the gravel. The yahoos and their pimped out pick ups just love to give her at stop lights and spray the other cars, and pedestrians, with the gravel. I've had one cracked windshield and a nice cut on my cheek from those a$$holes. Its almost impossible to nail them too.

Brian, you have my vote for the "Dedication Award" o the year. I'm feelin' guilty just reading your post.

How abut a monster truck version of a pre-A coupe?

Brian - maybe you need on of these with your 911 engine put in it...

..and wouldn't you know it the new alternator has a larger diameter thread than the old and didn't come with a nut. Now I gotta source a larger nut. All the shims were behind the pulley,,,right?

As far as roads, I was on the ice road today to go kite skiing. Gotta drive through about 10 inches of water by shore to get on the road but once out a ways there's very little water. Unseasonably warm these days and supposed to rain of all things! If the snow goes off the ice it'll be fast kite skiing.