e28 motor swap Q

Post your E12 technical questions and comments here. Please, no off-topic posts.

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syracusegli
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e28 motor swap Q

Post by syracusegli »

first off, the new format is awesome, i cant wait till everything has been worked out. :thumbup:

i have a 88 535i parts car..

what do i need to use my stock e12 5spd tranny?
i did read the motor swap write up but i am still confused.

thanks for any help.
Martin
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e12 5 speed w/3.5

Post by Martin »

OK I just read that FAQ too. It does not say exactly, and I am no BMW expert, but I bet that you just bolt it to your trans with the 3.5 flywheel and clutch.
I think the best thing to do is compare the two engines flywheel and clutch assemblies, if they are different then you need to use the the parts off your e12 motor, if they are the same then use which ever one looks to be in better shape.
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Mike W.
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Re: e28 motor swap Q

Post by Mike W. »

syracusegli wrote:first off, the new format is awesome, i cant wait till everything has been worked out. :thumbup:

i have a 88 535i parts car..

what do i need to use my stock e12 5spd tranny?
i did read the motor swap write up but i am still confused.

thanks for any help.
It depends on what you want to do, exactly. If you want to retain the original L-jet with distributor, you need to swap all those parts, and remove the cam nut and replace it with the conversion one. Below is a pic of one with the distributor drive installed.

Image

Or if you want to use the motronic engine management, you would need a motronic bellhousing for the 265 tranny for the two flywheel sensors which give critical inputs to the ECU. Those are a little hard to find and go for around a hundred. Also if you use the motronic intake manifold, you need to use an E21 power brake booster, or perhaps a very early Bav one, along with installing a vacuum hose fitting in the intake manifold as E28's used a hydro booster. Or do that conversion, but I wouldn't. And of course install the motronic harness and ECU.

There's more little details, but those are the high points.

Mike
Mike W.



1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
syracusegli
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Post by syracusegli »

thanks mike.

im actually going to run Megasquirt
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Karl in KS
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Post by Karl in KS »

Was your original question about fitting your current 5-speed to the newer engine? It will bolt right up. If the donor car had an automatic transmission, your flywheel will also bolt right up to the crankshaft in the new engine. That's what I did.
syracusegli
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Post by syracusegli »

yes, so i dont have to swap bellhousings then?
04-jettaGli
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Mike W.
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Post by Mike W. »

syracusegli wrote:yes, so i dont have to swap bellhousings then?
Only if you are going to run E28 era engine management. Well, Megasquirt has to pick up TDC and timing from somewhere, but the later B35 era using a toothed wheel at the front of the crank would probably be easier.
Mike W.



1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
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trevor LI
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3.5L / Motronoc upgrade

Post by trevor LI »

I'm upgrading with the e34 535 motor and motronics including wiring harness with diagnostic port from donor e34. Presuming the e34 has on dash check engine displays etc, where would we get our warnings/reminders on the e12 which has no display?

00=[]=00

Regards!
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E39 2001 5spd
1974 2002 5spd
E12 1980 5spd rustbucket (Junked RIP)
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1st 5er
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Post by 1st 5er »

Listening in... :)
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syracusegli
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Post by syracusegli »

so back to this...

if i swap in my 88 535i motor, harness and ecu..
i need a hydro brake booster?
what about for the tranny? the e28 fly/clutch works with the e12 tranny?
the FAQ is vague to me, i read it a bunch and im still a bit lost

i will be keeping the stock e12 tranny that is in there.
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DMS
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Post by DMS »

No you don't need to swap anything of the brake system. Perhaps it's different because I'm in europe but I didn't swap anything. I used an 88 M30B35 with motonic. There is not much clearance between the inlet manifolt and the brake booster but it fits just fine.

Concerning the warning lights what else do you need then the ones you have in your E12? Just connect those and you'll be fine.

Image

Image

Concerning the gearbox. I use the E34 5-speed one. Gives me almost the same gearing like an E12 4-speed one + and overdrive for the high way. At 2750 rpm I'm at 140 km/h. It's just perfect.

Any questions please ask.
E12 M30B35, VEMS, HX52 never getting finished.
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RonDwyer
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AH HA!

Post by RonDwyer »

So it fits with the stock booster! Might have to keep the car and do the conversion...
Ron Dwyer
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Mike W.
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Post by Mike W. »

Image

That doesn't quite look like the US spec brake booster, it looks smaller. The trick here is to use one off a E21.
Mike W.



1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
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DMS
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Post by DMS »

Yes that's perhaps something to keep in mind. This is a euro car! I've no idea about all the differences.
E12 M30B35, VEMS, HX52 never getting finished.
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