E30 M10 a/c compressor mounting bracket

I have '87 E30 with M10 engine, and I am in a process of fitting a/c from a wrecked car. It's time to fit a/c compressor now (everything else is finished :-)

My first question is: does the compressor have to be at predefined angle, or can I rotate it 30 degrees around rotor axis?

I am asking this because the compressor has a mounting bracket for M20 engine (not sure about that), and I have M10. Existing mounting bracket attaches to the motor in a vertical plane, and for my engine that plane is at 30 degree angle.

Since I do not knew in detail how does compressor operate, I do not knew if rotating it for 30 deg. around the axis of rotor rotation would do any damage. And it would be the easiest to fabricate bracket like that.

Now my second question. If rotation can damage compressor I have to fabricate more complicated bracket, that will be heavy if I use steel. Would aluminum be good enough to hold (pretty heavy) compressor?

Reply to
me
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Here's a link to the parts shown in Realoem for the '87 325i.

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They show the same bracket used on the '87 320i but show a different bracket used on the '87 318i
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It appears that the 325 bracket uses different bolt locations for the attachment to the block so that may present a problem. I don't think that the orientation of the compressor around it's rotation axis will have any effect on it although the hoses may not reach if they were meant for the other mouning orientation.

I hope this will help you

Reply to
Jack

I am not sure exactly what you mean by rotating it by 30 degrees, however the compressor needs to be fitted so that it runs in dead inline with the crank pulley, otherwise the belt will come off and possibly take out the PAS/alternator belts, etc at the same time. It also needs to be installed so that you can get the belt on and correctly tension it. In addition to this, the air con pipes will need to be able to fit onto the compressor properly.

If you need to make a bracket, I would personally make it out of steel. Can't you just try to get the proper bracket?

Reply to
Stu

Nedavno Jack pise:

I know about difference in bolt locations, and that is one of the reasons I want to fabricate new bracket.

What about lubrication of the compressor? IIRC when you transport home refrigerator in non-vertical position, you should wait for some time before you turn it on, and I think that the reason for that is that oil that is inside needs to go down to the compressor. And that is my concern here.

Hoses can reach compressor, I checked that.

Reply to
me

Nedavno Stu pise:

When you are in front of the car and look at the a/c compressor, connections for the hoses are at the top of compressor. By rotating compressor 30 degrees I mean that connections for the hoses are now not on the top but 30 deg to the left. English is not my native language, but I hope you understand now.

I am asking this because there is some a/c oil in compressor, and I guess it it's there to lubricate something. If i rotate compressor that oil might not where it is suppose to be, and that is not good.

I am on a tight budget, bracket alone is more than US$300. Check here:

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Reply to
me

There should be no problem. The compressor actually uses the refrigerant for lubrication and unless the system is leaking, the 30 degree angle you're talking about should make no difference at all. As long as the hoses reach, you should have no problem at all.

Ed

Reply to
Ed Beroset

I assume when you say you can fabricate a bracket in aluminium you mean duraluminium. Duraluminium would be fine. Just keep it as chunky as possible. In fact the one in your link, looks like it's made from an ally casting rather than a steel one.

Personally though, having access to a welder and a m/c shop, I'd be inclined to fabricate one from steel. Not because I think it would be better or stronger, but simply because I think it would be easier to make. If you do take the welded steel fabrication option, you can reduce the chances of it cracking, by having it stress relieved, once it's completed. Either have it done commercially, or simply get it red hot it in fire and let it cool slowly. Chucking it in a nice bonfire would do fine. :-) Mike.

Reply to
Mike G

Nedavno Mike G pise:

Thank you for the suggestion. Since Ed suggested that rotation of compressor for 30 degrees around rotation axis will not create lubrication problem (anyone to confirm this?), fabrication will be very simple. 1/2" steel plate and 7 holes to drill, and that's it.

Reply to
me

Nedavno Ed Beroset pise:

That simplifies fabrication a lot. In this case I only have to get a steal plate 15mm (1/2") thick, and drill few holes in it.

If compressor uses the refrigerant for lubrication, what is a/c oil than for? My manual says that I have to put in correct amount of a/c oil for every component I change (compressor, hose...)

Reply to
me

There wont be any lubrication problems, because the oil is atomised in the refridgerant. In effect this covers all the internals in an oil mist. Mike.

Reply to
Mike G

Nedavno Mike G pise:

OK, than my problem is solved.

Thank's to all.

Reply to
me

Sounds right. Also you made a funny joke there without even trying! :) (I know English isn't your first language; steel = a kind of metal, steal = to take something illegally). The advantage, of course, is that steal plate is much cheaper. ;)

That's because the oil is distributed within the refrigerant. Technically my statement should have been "the compressor actually uses the refrigerant *to distribute* lubrication." There's still oil involved. The manual's method is an attempt to assure that you have the right oil/refrigerant ratio. Too much oil and your AC becomes less effective; too little oil and your compressor seizes due to lack of lubrication.

Ed

Reply to
Ed Beroset

Nedavno Ed Beroset pi?e:

| Sounds right. Also you made a funny joke there without even | trying! :) (I know English isn't your first language; steel = a kind | of metal, steal = to take something illegally). The advantage, of | course, is that steal plate is much cheaper. ;)

:-)

| That's because the oil is distributed within the refrigerant. | Technically my statement should have been "the compressor actually | uses the refrigerant *to distribute* lubrication." There's still oil | involved. The manual's method is an attempt to assure that you have | the right oil/refrigerant ratio. Too much oil and your AC becomes | less effective; too little oil and your compressor seizes due to lack | of lubrication.

Thank you.

Reply to
Yvan

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