E36 M42 into an E30 M40? Swapable?

[ron1999]

Hii all
seeing the amount of info running along, i hope this is a good place to ask this question:
i have an M40b16 E30.
i also have access to an M42b18 E36 car.
i was thnkng about taking off the engine and tranny and put them in my E30.
i know the engine block's are the same. should i expect a bolt on swap?
is there any other suprises coming along?




Ron

[Gunni]

swap oil pans, and transes,

rest should be easy

[jaistanley]

I'm not 100% but I think the transmission MIGHT have a slightly different angle meaning you'll have to adjust your gear shifter (no biggey). You'll probably need to find a diff with the correct ratio as other E36's use gearboxes that need lower ratio diffs (probably a service life and noise thing). For the reasons above I'd say go for an E30 M42 gearbox if possible unless you can find a suitable diff easily.

The sump is needed from your 318 to clear the crossmember.

The exhaust from an E30 will be required, possibly also the manifold to clear the steering mechanism.

The wiring will be pretty straightforward (new plug on the engine loom is all I beleive) as those early E36's didn't have the EWS security system.

I'd personally go for the diff from a Z3 1.9 with a LSD specced from factory, coupled with the engine and tranny from the E36 (if the gearboxes rewuire the same ratio that is). They are a torsen type LSD - Very swish.

All this seems a bit of a hassle. Unless you are emotionally attached to your car or love getting oily and cold, E30 318is's are very cheap these days and the sale of your cars and parts might pay for one easily. You'd then have the better suspension and brakes, the cool spoiler and seats, black headlining etc.

Remember the saying: Never do an engine swap to a car you can buy.... Well I said it anyway.

Good luck.

Jai

[ron1999]

I Guess my Location tells you very little - but here in Israel, an IS is rare to find...
The number of E30 IS is less than 5 while the E36 there's must be about 300 cars all over, so this E36 is pretty much of a thing for me.

i was sure that the swap would be very close to bolt-on \ bolt off kind of, and will not require too much of a hassle - this is why i perferd using the E36 engine and tranny all together - to save me the part of re-attaching the E36 IS engine with my E30, M40 gearbox.

now, if the gearboxes are not the same - i think i'll rather stay with my old gearbox (very very short) and go for a lower ratin diff. (the setup on my car has me going on about 3000 revs for the speed of 100kmh, the diff is 4.27)
now since my car is my daily vehicle i cant let it go crazy with the economy - so i must keep it under the resonable proportion of power / fuel cons / reliability.

so just to make sure im getting all the things straight
1. can i use my current M40 wirilg loom along with the M42E36 engine or do i need the E36 loom as well?
2. is the gearboxes different or maybe swapping gear's mounts can solve me the gearbox's issue as well?
3. should i expect cluster problem after swaping? rev counter? speedo. ? fuel?


thank for the information again


Ron

[jmc330i]

I'm not 100% but I think the transmission MIGHT have a slightly different angle meaning you'll have to adjust your gear shifter (no biggey).

Thats a difference between the M20 and M50s.

I would say there shouldnt be a problem with the M40/M42.