Firstfives.org

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.

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.

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.



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

thanks mike.

im actually going to run Megasquirt

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.

yes, so i dont have to swap bellhousings then?

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.

Listening in...

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.

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.





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.

So it fits with the stock booster! Might have to keep the car and do the conversion...

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

Yes that's perhaps something to keep in mind. This is a euro car! I've no idea about all the differences.