European M40 -> M42 SWAP

[Max399]

Hello guys,

I am from Europe and i have an 88' 318i which has the European M40 engine.
The engine is alright but i am really searching for a little more power and also fuel economy. I could easily go for the M50 SWAP which is really common here - but i really want to keep the 4-banger :)
So i want to use the E36 M42 engine.
So far i came to this information, if someone can confirm or deny it - i would be really grateful.

- I need a pre-1994 engine, becase later the EWS system was introduced.
- My original gearbox (Getrag 240), drive shaft, diff (4.10), flywheel (Single-mass) and clutch can be reused.
- The wiring is pretty easy, i've found some schemes already.

But of course i've got some questions:

- Which engine mounts should i use? My M40? E36 M42? Which ones?
- Is there anything needing change when using the E36 engine? The only problem i see is the M40 exhaust, if i reuse it - it sits too close to something, is that true?

Also what are the major things i would need to replace when doing the M42 swap? Ie what needs to be refreshed? I know the M42 problem is the oil-leak in the chain cover so that gasket needs a change for sure. Anything else?

Thank you,

Max.

[Cavey]

+1 - I'm in the same boat looking to swap from a 316i M40 to an M42 and the E36 motors are a lot more common than the E30 motors over here in the UK.

Cavey

[papa_geza]

i'm using m40 and stroke with M44 crank + M44 rod n piston + using 276 degree 11.6 lift camshaft

"i hope i can catch M42 engine with my M40"

[Max399]

My M40 is only doing 190km/h, can't go more :)

[MX339]

I just finished swapping an E36 M42 into my 318is. Now I'm not sure about the specifics of an M40, but what I ended up doing for the swap was using the E30's intake manifold, oil pans, engine mounts, and wiring harness as that was the easiest option for me. I did use the E36 exhaust manifold as well, which was nearly the same dimensions as the E30 manifold.

Where you will most likely run into issues will be the intake manifold and oil pans. You've really got to have the E30 pieces to complete the swap. I don't believe you'll have any problem using an E36 wiring harness and DME though, as long as it's OBD-1.

[Max399]

When swaping M42 over M40 - you need to keep you'r old M40 oil pans, engine mounts.
As far as i know you can keep the E36 intake, but the E30 M42 is much better in flow.
The exhaust - you can use M40 one, but it will be really close to one of the control arms, so it would be better to use the M42 one, or custom..