Valeo vs Bosch Alternator Difference
 

Why is there a difference here? The bosch is .435 deeper than the valeo. I know I'm going to have to machine the housing, no problem there. My question is why is there a difference and why would the fan housing carry the same part #?
http://forums.pelicanparts.com/uploa...1197230184.jpg

one carrera one sc or 2.7

get different housing, dont machine

John, What's the part number I'm looking for? BTW these are both out of 84-89 carrera's

Bump for my confusion.

Just changed the one in my 87 Carrera, it was a Paris-Rhone, and looked like the one on the right. Beyond that I can't help, but I thought you might like to know. :)

ianc

Here's another picture with the alternators sitting on the surfaces that rest on the mount. The short one is from my '80 SC. The taller one was for an '84+ Carrera. The two alternators use different fan mounts so that the fan sits in the right place axially so that the fan belt lines up with the crankshaft pulley.

If both of those alternators came from '84-89 Carreras, the one of them has an SC fan mount to match the alternator.http://forums.pelicanparts.com/uploa...1197419756.jpg

That's what I'm wondering. Maybe someone changed the alternator and fan housing on my 87 3.2L? What I'd really like to know is for certain what fan housing number I need.

Mine had not been apart before. Perhaps they used both of them throughout the years depending on which alternators they had in stock? Have not searched on this here before, but I bet more info can be found...

ianc

"Perhaps they used both of them throughout the years depending on which alternators they had in stock?"

Not the case! Both are Paris-Rhone (Valeo). The smaller size is a 75 amp used in the
'82-'83 911SC (total junk/very unreliable/poorly designed). The larger is a 90 amp
used exclusively on the '84-'89 911 Carrera and some 911 Turbos over those years.

My 87 is of the smaller type, clearly marked Valeo, Paris-Rhone, and also 90 A.

ianc

"My 87 is of the smaller type, clearly marked Valeo, Paris-Rhone, and also 90 A."

Then it's marked incorrectly, as that alternator is incapable of a continuous 90 amps without a failure,
and it's marginally reliable at its 75 amp rating. That's why the alternator was replaced with a totally
new design capable of 90 amps.

Loren, I just today talked to the original owner of my engine and he said he did not change the alternator or housing on the engine. Could there be a few 3.2s out there with the older style alt. and housing? PS- I still need to know what part number to look for. 930-106-102-07????

"Could there be a few 3.2s out there with the older style alt. and housing?"

It's possible, but highly unlikely especially for a USA/Aus/Japan car.
Maybe some ROW, e.g. gray market, cars with minimum electrical
accessories, e.g. without power seats/windows, etc.

Bottom line: It's best to NOT use the Paris-Rhone 75 amp if replacing
the alternator AND a late housing is available.