please help me identify this alternator

[911scfanatic]

Pics below. Can anyone tell me the make, year(s) and wattage? What other marks or measurements can I provide to help in the identification? TIA.

[edmayo]

Looks like a 69-74 Marelli. A Bosch will usually have an identifying tag rivited to the housing. A Bosch will usually have the field terminal on the brush holder, and the thread pitch of the pulley nut is coarse, while the Marelli is a fine pitch, (1.25 vs. 1.00 I think from memory) Usually that rear bearing cover plate has Marelli on it, but that looks to have been blasted off. Those are generally 500 watt units.

[911scfanatic]

Thanks, Ed. I will check the threads.

[304065]

Ed, you mean Motorola/Marchal SEV. Should be red, this one has been painted. Also missing "trio" (only one in the Motorola) diode plate.

Also this has been converted to internal regulator, that is the silver box where the brush holder should be. Maybe that is why they removed the trio diode? Odd.

I don't like internal regulators 2" from the engine case.

[edmayo]

I just said Marelli to see if anybody would catch that At least that's what I used to tell my students when they caught me in mistake !! Ditto on the internal regulators! defies all rules of electronics by putting them right above a major source of heat. However if it weren't for alternator failures there wouldn't be much to do on 3.2 Carreras!!

[Frank Beck]

Nothing says Pep Boys like spray painting a "rebuilt" (doubt it) alternator after it's all together. I would think twice about using it; brand new Veleo's aren't that expensive.
Also you might want to spend $22 for a new pulley half; yours is pretty worn and will just create extra wear on the fan hub.

[Jim Breazeale]

This is the way your S.E.V. Marchal/Motorola Alternator looked before it was "improved". I think it looked better the old way.

Regards

Jim

[911scfanatic]

Yes, Jim, that looks much nicer. Unfortunately, it looked that way before and after the rebuild. The internal regulator had already been added and the plate removed.

I suppose the best thing to do is pull it all apart to check the brushes, bushings and bearings to see if they have indeed been replaced.

I don't suppose there's spare parts readily available to return it to its former original glory?

EDIT: Also, couldn't my alternator still be externally regulated but with a different brush plate and the large red plate removed? What is it exactly that the red plate does? Look at the one here advertised by Vertex. Looks just like mine, but without the cheesy silver paint. I'll pull that plate tonight and check. I suspect it's just a different brush plate that is available as an assembly rather than the remanufacturer going through the trouble of soldering new brushes onto the old plate.

[Frank Beck]

A brand new alt is less than $400. Your time has to be worth something?

[911scfanatic]

This is a spare, so I don't even need it.

When I work on Porsches, I'm off the clock. I do it to relax so it's not a big deal. I enjoy this stuff.