m50 alternator sizes

[tonytony]

Is it me or does all the m50s come with a giagantic alternator? I mean this one is huge!!!! I was browsing bf.com and there was an 80amp bosch alternator, and it looked a 1/3 of the size. I'll post pictures tomorrow. And i do have a bosch alternator

[The Fast One!]

you might have the upgrade every one gets which is the 140amp alt.

[PiercedE30]

140 is the way to go. I got it. The thing is pretty huge. Even has it's own cooling ducting.

[rede30]

I guess my motor came with the big one because i was confused when i saw a cooling duct. When you guys say it was an upgrade was it a factory option or did the small ones take a dump and they put in a bigger one?

[tonytony]

I think the cooling duct comes standard on all of the alternators i think cause even the 80amp that was for sale had it. I'm confused i guess it's a good thing i have the big one

[Beej '86 325es]

I believe there was a Bosch and a Valeo alternator available. I assume one is the 80 amp and one is the 140? I imagine the 80 amp has less drag on the engine, right?

[02stu]

I have only seen the alternators with the cooling duct on them, I would guess that if you see an m50 without out it, it means it has been replaced. Like Beej said the smaller alternator will have less load on the engine. Unless your powering a serious sub or something crazy I doubt you'd need a bigger alternator, correct me if I'm wrong though

[Beej '86 325es]

Upon further research on pelican parts, it looks like there were 3 different alternators.

80 amp Bosch
140 amp Bosch
140 amp Valeo

I believe when you order the UUC pullies, you have to specify whether it's a Bosch or Valeo alternator.

[tonytony]

i hear the pulley for the alternator could be used for both......hmmmm

[matt]

Both Bosch and Valeo? No.

[tonytony]

OT but how do i remove the alternator pulley so i can put the new underdrive on, there's no place i can grab onto so the pulley doesnt' spin while trying to loosen the nut

[matt]

You need to use an impact gun.