How easy is an e36 318ti m42 for my e30 318i m40 engine swap

[benurminge]

Topic says it all. I have an e30 touring 318i with an m40 engine, it's a little tappetey and needs the cam belt replacing so I'm considering an engine upgrade, I can get my hands on an e36 318ti m42 engine.
I was wondering how easy it is to change?
I have read into it a little...
I think my gearbox will fit fine, I will need the m42 ecu but unsure if I will have to change the loom aswell?
Does the engine fit straight onto the mounts?
Etc etc...
Cheers

[benurminge]

Also just realised there is a hole sub topic forum about m40/m42 engine swaps... Idiot!
Still any help would be appreciated.

[benurminge]

So basically all I need is this lot?


1.M42 engine
2. E30 M42 engine loom and ECU (will work with E36 engines also, saves having to adapt E36 looms and causing issues!)
3. Coil packs and HT leads or COP conversion
4. M42 exhaust manifold
5. 318iS exhaust system
6. M42 coolant hoses
7. M42 AFM to TB boot
8. Getrag 240 gearbox
9. 318iS prop

What is number 7? Sorry to sounds dumb!
Also number 8, gearbox: does this means I can use my m40 gear box? Which comes onto my last question, if I use my m40 gear box surely I don't need a 318is propsharft?
Cheers.

[Grrrmachine]

Have a thorough read:

http://www.e30zone.net/e30zonewiki/inde ... Swap_-_M42

and as for number 7:

http://www.e30zone.net/e30zonewiki/inde ... ubber_Boot

[TPS]

You'll also need M42 Engine Mounts, don't use M40 ones, They dealer only as well. I've done this swap, you'll notice the difference, better MPG, more power, highly recommended. Gearboxes if you use your M40 one, you'll keep the M40 prop. If you use the M42 one, you need the M42 prop.

[benurminge]

What's wrong with using the m40 mounts? And how much are the m42 mounts? Trying to weight up costs.
All I need is an e30 m42 loom and ecu. How much are these and how easily available are they?
Cheers

[flybmw]

Hi mate
I am doing right now exactly this type of swap.
M40 mounts are too flimsy for M42 lump. M42 mounts are way more expensive as they are hydromounts. Check it on ETK and see for yourself.
Why don't you put inside the e36 M42 loom and ECU from donor car? Simply swap and that's it.
I am using M42 from e36 318is with its own manual gearbox and propshaft + full exhaust.

[jmc330i]

I am using M42 from e36 318is with its own manual gearbox and propshaft + full exhaust.

E36 uses different gearbox ratios to the E30 so you will also need to swap diffs, unless you're happy driving everywhere at high revs. Not sure if an E36 prop will fit either - depends on its length I guess.

Also, the E36 exhaust (manifold or system) won't fit an E30 without a fair bit of modding.

I've recently looked at an E30 converted with an E36 iS engine. Looked to be a very good conversion with the E36 brackets welded in for things like the coil packs etc.
It's definitely a doable conversion, and in the absence of a known good E30 M42, one I'd consider.

[benurminge]

I can get the gear box from this engine with prop and the e36 loom and ecu. That be easier? I thought you had to fiddle around trying to get an e36 loom and ecu to fit the e30 car?
So what your saying is buy the 36 engine, hoses, ecu and loom, gearbox and prop, manifold, custom exhaust and all you have to do is buy the m42 engine mounts and it will fit straight in?

[benurminge]

Or are you saying its alot easier to fit an e30 m42 engine complete with box ecu etc etc which would literally drop straight in and off you go? Easier then better!

[jmc330i]

Using an E36 gearbox means you will have to swap the diff for a different ratio.
As you've got an M40, just use the M40 gearbox, prop and diff. That's what I'm using with my M44.

Using an E30 M42 will be the easiest. If you use an E36 M42, you can use the E30 M42 loom, ECU, inlet etc etc, but tbh I'd say just use the E36 stuff and swap the loom plugs - its no more difficult than wiring an M50 conversion.

Whichever engine you use, you will need the E30 M42 engine mounts, hoses, exhaust manifold and system.

I'm also starting with a 318i touring and the basics I'm using are -
E36 M44 engine, ECU, loom (modified as per M52 conversion) and inlet.
E30 M42 engine mounts, hoses, exhaust manifold and system.
E30 M40 gearbox, prop and diff, upper and lower sump.
E30 M20 flywheel, clutch and starter.

[benurminge]

Okay thanks alot! I think I have got my head around all this now! Thanks alot for the help guys.

[DanThe]

M44 would be more worthwhile IMO, even though its extra work

[flybmw]

I am using M42 from e36 318is with its own manual gearbox and propshaft + full exhaust.

E36 uses different gearbox ratios to the E30 so you will also need to swap diffs, unless you're happy driving everywhere at high revs. Not sure if an E36 prop will fit either - depends on its length I guess.

Also, the E36 exhaust (manifold or system) won't fit an E30 without a fair bit of modding.

I've recently looked at an E30 converted with an E36 iS engine. Looked to be a very good conversion with the E36 brackets welded in for things like the coil packs etc.
It's definitely a doable conversion, and in the absence of a known good E30 M42, one I'd consider.

thanks. this is very helpful.
I have a 4.45 stock diff on my touring. What type of diff should I put instead to match with e36 M42 engine and gearbox? Ideally, I want one with LSD.

[jmc330i]

I am using M42 from e36 318is with its own manual gearbox and propshaft + full exhaust.

I have a 4.45 stock diff on my touring. What type of diff should I put instead to match with e36 M42 engine and gearbox? Ideally, I want one with LSD.

I think the E36 318iS has a 3.45:1 ratio diff, so you'd ideally be looking for somewhere around that.

What engine and box did your touring start out with?
If your touring was an M40, I'd just use the gearbox, prop and diff from that.

[flybmw]

I am using M42 from e36 318is with its own manual gearbox and propshaft + full exhaust.

I have a 4.45 stock diff on my touring. What type of diff should I put instead to match with e36 M42 engine and gearbox? Ideally, I want one with LSD.

I think the E36 318iS has a 3.45:1 ratio diff, so you'd ideally be looking for somewhere around that.

What engine and box did your touring start out with?
If your touring was an M40, I'd just use the gearbox, prop and diff from that.

My touring is M40 with automatic gearbox. It being automatic makes use of prop and diff meaningless I suppose. Now I threw in M42 lump with manual gearbox and propshaft taken from e36 318is.

Like you said, I am worrying whether stock 4.45 diff will make sense on this conversion...

[TPS]

Pm'd