Air conditioning + m30 swap

[CorvallisBMW]

I know the m20 bracket does not fit the m30, you have to use the m30 bracket.

I installed Otis' motor mounts, massaged the firewall behind the head just a bit and everything fits great. Compressor bolts right up. But the standard m20 belt isn' long enough, I'll have to find a longer one that will reach.

[Jean]

Are you using a BMW M30 Seiko Seiki 6452 8 350 060 compressor?

[CorvallisBMW]

Nope, late model m20 compressor with modified m30 bracket

[deansbimmer]

Any R134 specific compressors that bolt up?

[Jean]

Nope, late model m20 compressor with modified m30 bracket

What / how was the m30 bracket modified exactly? I am still thinking about finishing up a/c or not....

[CorvallisBMW]

I'll post pics of the modified bracket when I get home tonight. Just some material removal, easily done with a bench or angle grinder. My compressor is a Seiko unit, not sure of the p/n but I'll post it up too.

[Jean]

Cool.

[Wishno87]

The car i just bought still has good AC so im thinking about this.

[CorvallisBMW]

Comparison on m20 vs m30 brackets. Note difference in inside radius where the compressor sits:







Modification of m30 bracket:

[Jean]

^ with that modification to the m30 bracket m20b25 a/c compressor fits right in? Can you post a part number of the compressor you used?

[CorvallisBMW]

Yes the m20 compressor fits great with the modified bracket. You only have to remove a small amount of material, 1/4" or so. If you mock up a compressor and bracket ahead of time you'll see that the compressor hits the bracket and doesn't allow the top mounting hole to line up when the bottom is already bolted in (or vice versa)

I'm running a Seiko compressor, BMW p/n 64521386464, Seiko p/n SS-148PL3

[Jean]

I have two m30b35 compressors on hand but don't have an m20 one, is the m20 one smaller (shorter)? Did you do this to clear your radiator or because you didn't want to deal with custom lines/fittings?

[Wishno87]

Does it need to be a late model one like yours or will my early model work too?

[CorvallisBMW]

I have two m30b35 compressors on hand but don't have an m20 one, is the m20 one smaller (shorter)? Did you do this to clear your radiator or because you didn't want to deal with custom lines/fittings?

Does it need to be a late model one like yours or will my early model work too?

I have no idea. On both counts.

[chadthestampede]

Did you ever figure out the belt situation?