The late alternator I got for Liz doesn't fit. It's about .5" too thick.

I'm trying to install an internally regulated alternator in a '77 engine.

Anyone?

I'll be in SoCal the next two days and will bring the alternator with me. If anyone has a Carrera alternator I could see, I would be appreciative.

Yea, to install a late model Carrera internally regulated alternator in a early style fan housing you have to machine off about 3/4" if the internal step. You can kinda see it in this picture, it is the area that the powercoating has been shaved off.

-Britain

Before:


After:

Why is there no mention of that in this Porsche bulletin?

That bulletin is for the -SC alternator. The later carrera alternator, also internally regulated is bigger. Carrera fan housings are rare as hen's teeth, partly due to their tendency to crack. I ended up buying a new one... If you end up going that route, there happens to be one on 'bay now that looks to be in good condition: 8060067042.

I'm happy with my set up - very clean. FWIW, a lot of the 911 guys recommend going back to the externally regulated setup due to premature failure of the internal regulator, felt to be due to heat from closer proximity to the motor.

Oh, and you'll also need to notch the air deflector on the back of the alternator to clear the regulator. When you try to put the deflector on, the area needing the notch is obvious. A couple minutes with a dremel sanding drum fixes that.

This is good stuff. Any more tips?

I thought the alternator grounded through the fan housing. Such a fancy painted fan shroud might cause grounding problems would it not?

3 diff. depths, early fan housings, all 3 same overall dimension outside. front to back.
There is 3 different thickness ,28mm/19mm/7mm,
this is measured with calipers from your shiny surface to to back side.
I have cut em deeper no problem, I used a cnc mill, and a lathe (scary).
oh ya grounded through harness and needs a ground wire from alt. to the engine
hope this helps
upper left housing is the deeep one

This has been very informative.

Thanks guys.

Anyone have the correct housing to sell me?

Are there not different diameters as well? I know the racing engines used a small diameter fan, but were not regular production engines using them as well? Somehow I recall that the early 11 blade type were large diameter as was the 5 blade type that followed it. Then the new 11 blade type after that was a small diameter like the racing engines. Does that make sense? My book is out on loan, so I cannot look it up.

The fan blades are different diameters but the housing stayed the same.


Good call on the grounding, I will add a grounding wire.

-Britain

This thread needs a...

The housing is at the machine shop to be 'corrected'.

Interestingly enough, I think the housing on Mike's 3.2 has the same part number as the one I'm modifying for Liz.