Alternator bracket question

[gwittman]

I recently acquired an alternator bracket as a backup for my recently weld repaired one. My coupe is an early 70 production and it has an aluminum alternator bracket. I bought my 2800CS when it was 10 years old and I doubt the bracket was replaced during that time. The backup bracket I received is made of steel. Is there a timeframe when BMW switched from steel to aluminum or visa versa?

Not a big deal because it should not be more than a couple lbs difference , but I am just curious.

 

[HB Chris]

Are you trying to send me down another rabbit hole?

 

[HB Chris]

One of mine is aluminum (Malaga) and one is steel but I’ve been know to swap around for the best part and both I have I replated.

 

[rsporsche]

since my coupe had an engine change, i have no idea if mine was right or wrong. since the new engine, i have the newer e28 style

 

[Stevehose]

Aluminium in my June 9 '72 build

 

[eriknetherlands]

Alu in my may 73 swiss delivered car, but it has an e3 engine from 74, so not sure if my bracket belongs to the today's engine, or the car.

 

[sfdon]

Keep in mind- 2 different bore sizes for the top bolt and 2 different opening sizes for the alternator top mount depending on who has been in there....

AL41X
Al45X

 

[gwittman]

The steel alternator bracket looks the same as my aluminum one. I have not measured everything to be sure it is exactly the same. I can adapt if the holes are different sizes with bushings or drilling them larger. I just need them to be in the right place.

I was just surprised they came in either steel or aluminum. Thanks for the information so far. Still a mystery to me.

 

[Koopman]

I may have one if someone can email a photo or two.
Thanks

 

[HB Chris]

E3/e9 bolt is m10, e12 and later is m8 so easy to tell.