E30 Zone

I've recently just bought a e30 325i engine from someone, the m20 engine.

It apparently comes with everything, gearbox, ecu and all the ancillaries, he even chucked in the downpipe.

what else will I need to change or prepare for?

Will I need to change my diff and prop shaft or can they be used (Plug and play)

What diff do you have? You might want to change it for a different size one, but the prop and diff will be fine, but you'll need to upgrade the braking system too...

Brakes and suspension?

The diff I think is just the standard diff from a 316i from the E30, not entirely sure which one,
I'll try and find out.

I agree with my brakes, they need doing anyway, ideally I want to keep drums on the back as I go to santa pod for skid events so drums are better for locking up the back wheels. Was thinking just decent drums, shoes, discs and pads.

My suspension has already been changed to SPAX PSX shocks and springs, lowered by 60mm I believe, so they should be fine.

I found out the diff I think is 4.1, apparently the ratio on the E30 325i is 3.75,

wouldn't it give me better acceleration just leaving the diff in I have now, of course I understand top end will be sacrificed.

Yeah, you should have quicker pull off speed with the 4.1

Sweet! exactly what I need.

So other than what we've discussed, it's pretty much plug and play right?

I'd wait for someone who has actually done it to confirm and I don't know much about the conversion to be honest...

I know if you using it on the road, you'd want to change the brake set up to disc all round but by the sound of it your using it for drifting anyway.

Would a 4 door system fit on a coupe model when doin this conversion

Sorry forgot to add the exhaust bit in there

Check out my 'wiring warning' sticky in this forum before you try to fire this conversion up!

Will do Brian! thanks,

also I've been told I could use the same prop shaft, but I've also read elsewhere you can't
can anyone confirm this?

you maybe have to change the front half of the prop shaft because different engines have different sizes not sure if the 325 is the same as the 316.it will fit but the splines might not go the full way into the rear half of the prop shaft but it bolts up.aslong as its in and u get the bolt tight it should be awrite.my friend drives around with his driveshaft like that and its fine.

Thanks for clearing that up Markg, I'll weigh my options out when I get the engine.

Also do you know what Fan will be good with this engine? I'll be using it for drifting and was thinking an Electric Fan, would I need one from the E36?

i drift mines aswell and it seems to be awrite with the standard fan i just turn the blower up full and the heater up full.helps a little do you know any good tracks near scotland because i only have 1 to go to and its shite?

Here's another problem, my standard cockpit fan doesn't work haha, I'll be getting that sorted over the next few days though :/

Erm, I'm not too sure unfortunately, I will be travelling to Littlehampton way for DWYB at Santa Pod.

Quite a travel for the both of us consider I'm the South of England and you're the North.

Also, due to money being a bit of an issue right now.
Is it ok to use standard cheap discs and drums, pads and shoes?

I just need to get my brake system sorted.

Asthenia wrote:Also, due to money being a bit of an issue right now.
Is it ok to use standard cheap discs and drums, pads and shoes?

I just need to get my brake system sorted.

brand new standard gear is ideal.

is the santa pod track any good i was thinkin of going down and making a weekend of it sumtime? aye the standard brakes are more than capeable

Anything else anyone can advise me before I go ahead with this?
Can I use my power steering pump from my 316i? for the M20 325i?

also can anyone suggest an order of taking the old one out and putting the new one in?

also the guy who I bought the engine off cut the bulk of the wires so he could use his loom etc.
He said I could use my loom and just fuse the wires to the bulk of the wires and it will work.
Is this correct?

Asthenia wrote: He said I could use my loom and just fuse the wires to the bulk of the wires and it will work.
Is this correct?

He's either an idiot or a con artist! You have not the slightest chance of getting this to run without a M20 loom.

I'm trying to understand what the loom is, it comes with the bulk of wires however it's been cut before it enters that bit where the plastic is covering over, bulkhead area. Is the bulk of wires the loom?

The engine loom runs across the bulkhead from one side to the other, with a large branch near the middle to the engine itself, where it is secured under the inlet manifold. From there, various tendrils extend to the actuators and sensors on the engine.
On the bulkhead, at the fusebox end, there is a 20 pin round plug and socket where the engine loom joins the car body loom, and apart from an earth wire and a wire to 12 volts + from the battery at the other end of the bulkhead, these are the only connections between the engine loom and the rest of the car on most E30s. An extra plug or two are connected on cars with electronic auto. transmission, and on those with aircon.
The engine loom passes through the bulkhead via a large rubber grommet on the RH side, and goes to the engine ECU which is mounted just above the driver's right knee.

Brianmoooore wrote:

Asthenia wrote: He said I could use my loom and just fuse the wires to the bulk of the wires and it will work.
Is this correct?

He's either an idiot or a con artist! You have not the slightest chance of getting this to run without a M20 loom.

scotchblocks and stickytape FTW

you will want a 6pot instrument cluster also, possibly gear linkage.

Is the 1.6 fuel pump adequate anyone - I presume so

Barx325i wrote:you will want a 6pot instrument cluster also, possibly gear linkage.

Is the 1.6 fuel pump adequate anyone - I presume so

Fuel pump is the same.
Changing the instrument cluster would sort the rev. counter, but mess up the fuel gauge. The existing cluster needs to be fitted with a six pot coding plug, on the lower right front of the cluster.

I was going to suggest the tank aspect but I guess a fuel gauge is reasonably important - more embarrassing than a non working rev counter.. On a reverse note, will a cluster (originally from a 6 pot) with a 4 pot coding plug fitted give any rev counter issues still?

I had this issue, withstanding the fuel gauge problem

Clusters are interchangeable, apart from coding plug, matched to the number of cylinders, and fuel gauge matched to the tank size.

I always thought that was the case & never had cause to find out - the one time I did I must have picked a duff cluster. Cheers for clearing that up

Well the wires are there but I think he's cut off the plug, couldn't I just wire my plug onto it and plug it in?

So you have the complete M20 loom with just the 20 pin plug cut off?
You could splice your existing plug from the four cylinder loom onto it, with soldered joints insulated by heat shrink sleeving, and it should work.
You will have a couple of wires in the loom that won't be in your plug, but these are for the oil level sensor, which won't matter to you, since your car won't have the 'check' system that goes with it anyway.
The warning about pin 20, in my 'wiring warning' sticky in the engine swaps forum still applies.

you will need a whole 325 prop, your prop will be too long, you could just swap the front half for a shorter one but the two halves of a prop are balanced together so are mated, so your car will shake like a shitting dog (like mine did when I tried exactly this)

Thanks for clearing that up Brianmooore, I just wanted to clarify it.

I heard the prop would fit alright, sbut a a man of experience I will try source a new prop, cheers John

Ok. M20 engine is on the mounts, just needs to be bolted up. Found out I'm gonna need the power steering pump for the 325i was the 316i one doesn't fit.

Wired up the bit of the loom on the new engine that was cut off (the plug) to my plug, wired together by colour coded wires, ignoring any wires I didn't have or need. Pin20 wire the brown one is already disconnected (As I'm using the plug from the 316i)

However, there's one thing I'm still skeptical about. The M20 engine came with an oil cooler, which I've never had to deal with before. How does it connect up, where do the hoses go and exit to?

Hoses come off the oil filter mount, which also contains a thermostat for the cooler.
Cooler itself fits behind the lowest slot on the front panel, which will have a blanking panel fitted on your 316i. Fits in place with a couple of mounting brackets and pipe clamps.
The cooler isn't really needed with modern oils, and the oil rarely gets hot enough to close the 'stat anyway, so you can save yourself the hassle of fitting it, and potential oil leaks by buying the oil filter adaptor for a 2 litre M20. Only around £3 - £4, new from BMW, IIRC.