M50 Conversion Advice

[Danstable]

I'm contemplating an M50 conversion on my 1991 325 Touring. As I understand it I will need the following, and I've put my best guess on prices:

Engine - Ԛ£450
Gearbox - Ԛ£30
Engine Mounts - Ԛ£125
Smaller Servo - A few quid from a scrappy
Modification to the manifold so it clears the steering coloumn - Ԛ£?
M3 3.25 LSD - Ԛ£250

Have I missed anything from the list and are my prices about right?

How big a job is this conversion? There will be me with no real experience, and one other that has done an M20 swap but not an M50. Are we looking at 1, 2, or 3 weekends work??!

Also, how much messing is needed with the electrics?

Finally, would anyone with more experience fancy a weekend in Manchester with a few beers??!

Thanks in advance,

Dan

[Martinaston]

I think you owe me a beer if your willing to part with that much cash for an LSD.

[jimmyg_e30]

i was just about to ask the exact same question....the m5 is the 2.5 24v right

[Danstable]

I think I owe you a beer anyway mate!.....I hope not to part with that much for an LSD.....but better to over estimate than underestimate I recon.

Yes, the M50 as far as I know is the 2.5 24v unit.

[jimmyg_e30]

sweet

what engine mounts do you need
can you use the e30 gearbox
what modifications do you have to do to the manifold

[Danstable]

As far as I know you can't use the M20 gearbox, engine mounts I think can be bought from someone on here?!

I can tell you no more than that I'm afraid.

[jimmyg_e30]

right who has these mounts for me

[Brianmoooore]

Engine mounts (alloy bit) are from a 320 or 325 E36. Engine mounts (rubber bits) can be standard E30 325, althiugh there are a few alternatives.
E30 gearbox can be used. Saves having to change the diff, but causes difficulties with the gear linkage.
Best to get, is a complete engine, gearbox, engine loom and ECU from an E34 5 series 525. Has the right sump, other things being equal should be cheaper and less thrashed.
All you will need then is the E36 mounts and exhaust manifold, although the rear manifold will still need modifying.
I have all the wiring connections in detail. Ask me when you get to the point of needing them.

[jimmyg_e30]

http://www.treehouseracing.com/conversionbody.htm

whats this for then i presume you will need more wireing other than this

[Brianmoooore]

http://www.treehouseracing.com/conversionbody.htm

whats this for then i presume you will need more wireing other than this

Bloody hell! I just looked up this link.
Over Ԛ£200 for something I could knock up in an hour or so!!.
Totaly unneccessary anyway. All you need to do is to chop a section off the old E30 loom about 300mm long from the C101 plug, fit a cable gland to the E34 wiring box at the c101 end, feed the section of E30 loom in through this, leaving the plug and about 100mm of wire outside the box, so that it will plug into it's matching socket.
The original E34 "C101" wires are then cut back into the wiring box and spliced to the E30 ones, mainly, but not always, matching colours.

[Danstable]

Excellent, thought the mounts were the specially made ones, must be mistaking them for the M30 ones or something.

Brian, do you think I am in the right area on price for a manual gearbox for the M50....or am I being optomistic?

Also, any other bits needed? Prop-shaft, exhaust etc?

[6potWil6pot]

Exhaust can be any E30 325i but the manifold needs to be made up, or atleast mine was. Take a look anyway



Was a dammn fast conversion altho its power delivery never made it feel unmanageable, shame i never got it on a rolling road; it must have given 200bhp!

[jmc330i]

http://www.treehouseracing.com/conversionbody.htm

whats this for then i presume you will need more wireing other than this

Bloody hell! I just looked up this link.
Over Ԛ£200 for something I could knock up in an hour or so!!

I couldnt believe that when I first saw it either. Its exactly what I made up for my S50 conversion. It cost me under Ԛ£10 and took me a couple hours to do.

[Brianmoooore]

Excellent, thought the mounts were the specially made ones, must be mistaking them for the M30 ones or something.

Brian, do you think I am in the right area on price for a manual gearbox for the M50....or am I being optomistic?

Also, any other bits needed? Prop-shaft, exhaust etc?

The best way to buy an engine and box is in a complete E34 525i, either rusty or accident damaged. Early non vanos ones can be picked up nowadays for a few hundred pounds.
Propshaft is E30 325, exhaust from the mount on the gearbox back is standard E30 325, front exhaust manifold is standard E36, rear exhaust manifold is shortened E36 manifold, and the bit to fill the gap was made up in half a day using bits cut from E30 and E36 front pipes.
The diff I used came from an E28 525e
You will also need an electric fan. The one from an E34 5 series with aircon, or a 7 series fits perfectly.

[Jhonno]

you can use the m20 box

[Brianmoooore]

you can use the m20 box

Already said that in my post further up, but it causes problems with the gear linkage because the gearbox will be rotated about 10 degrees from what BMW intended.

[jimmyg_e30]

so

e36 engine mounts full set
e34 525 engine and gearbox
e36 front exhaust manifold
electric fan
e34 ecu and loom


brian would you be intrested in knocking one of thses up for me so...

can i still use my 325 sport diff

[Jhonno]

you can use the m20 box

Already said that in my post further up, but it causes problems with the gear linkage because the gearbox will be rotated about 10 degrees from what BMW intended.

sorry didnt read the whole thread..

can solve the angle problem with a bit of bending tho

[Brianmoooore]

It'll never shift as smoothly as it did when attached to the M20 though.