81"SC Alternator

911 tweaks · 10-21-2006, 07:31 AM

82' SC Alternator of on bench since I am cleaning and checking out fan, schroud...

So, I thought as a safe bet "since Iam in here" that I would throw a new volt reg into the alt.

Well, as the pictures show, I received a different vreg.

So, my questions are:
1. I believe I have the 70amp alt per the markings on the back of the unit...
A. should I upgrade to the complete/whole new 90amp unit?
B. does this Machal unit look ok? I have no idea of its condition other than when removong it from the engine the heavy duty brown grnd wire was not connected to the case bolt. Does this mean it all could be fried?
C. alt seems to spin fine with a little grinding noise of the bearings? Is this normal or about to fail?
D. can I still get the correct vreg for this Machal alt or is that why there is the Tech Bulletin 1 titled "New Alt has intergrated Regulator" update which is the superceeded to unit that may be what is only avail now?
*** E. Anything else while I am in there?
Thanks guys...happy Saturday wrenching on Porsche's...

911 tweaks · 10-21-2006, 09:43 AM

I would think this is an easy answer for those whom have delt with this repair.

Any and all help, greatly appreciated. I have done a search and cant find my answers...

911 tweaks · 10-23-2006, 03:00 AM

Well...I was away for Saturday PM and Sunday and I am amazed that I received ZIP responses...

Should I post this on the general 911 list and not this engine one??

Any help on the questions I have asked from those whom have had the French alt, would be great.

Thanks alot...

cstreit · cstreit's Garage

It sounds like you're asking if your functioning alternator is okay from the pics? impossible to tell. If it's working, it's okay.

Upgrading to a 90-amp is unnecessary unless you are pushing the limits of the existing one, are you?

The Marchal one is fine to use. You already have the upgraded internal regulator version and not the older external style. The update from ext. has nothing to do with your setup.

mb911 · mb911's Garage

yours is a 90 amp unit same as mine on my 81 engine and you removed the brushes which are NLA but I have an extra set brand new lying around and your VR is external and kept right by the CDI box and has a 3 wire plug in it blue/brown/black..

sorry chris to diss you

911 tweaks · 10-23-2006, 06:45 AM

Thanks guys. So my Marchal alt as shown is showing the brushes only removed? If so, is there a measurement spec fro the length of the brushes??
As far as its condition, I have no clue. This is off a 81' doner engine which I have not run yet, of which the lg brown wire was not attached to the engine case, or for that matter, it was not attached to anything! Thus, is it fried? My hearing the bearings grind a little as I spin the shaft mean that it is on the way out??
Ben, do you have new "brushes" as I picture on top of the box?

Does anything from the pictures show pending no work? Is the rust on the 5 or 6 soldered wires visable from the windings mean bad news?

Should I send this to **************, whom advertises in Excellence for testing? Is this all worth it or should I buy a new Bosch unit or just put this back together when motor ready to start and go from there?...trying to plan ahead and minimize the things that will need attention after the initial start-up when resto complete...
Thanks again!!

mb911 · mb911's Garage

the marchels are wonderful units and typically fully rebuildable. I rebuilt mine for like 100 bucks. I don't know were limit on the brushes but I have brand new ones at home(if you need a set). I do know the alt is 980 watts and that the back plastic peices (bearing retainers)are gold so don't loose it. The bearings are probably fine but I am curious as to what you are hearing

mb911 · mb911's Garage

oh and many will attest that these are actually better then the bosch units.

911 tweaks · 10-23-2006, 08:00 AM

Ben, Thanks for your reply. I am on the fly today, however, do you know if these brushs are still avail? If not, what are you asking for the brushs? You can pm me the specifics. Please include your contact info as I need to speak with you also about a muffler. Bob

mb911 · mb911's Garage

pm'd you

cstreit · cstreit's Garage

Quote:

Originally posted by mb911
yours is a 90 amp unit same as mine on my 81 engine and you removed the brushes which are NLA but I have an extra set brand new lying around and your VR is external and kept right by the CDI box and has a 3 wire plug in it blue/brown/black..

sorry chris to diss you

Pssh, even a blind squirrel finds a nut occasionally.

no worries man, I didn't look closely enough at the pics, good thing you caught it...