engine swap question advice needed please

[Doc-Dori]

guys after 4 long months of restoring my e30 cabrio im thinkin of swapping the engine

at the mo it has the 12valve 325i engine but its very noisey as in the tappets!! ive only had them done and there still very noisey i had the cam done so its not that !!

this is probably a stupid idea and feel free to tell me if it is ???

mate has a 520I it has the vanos 24valve 2.0 engine low miles engine sounds so sweet !! not a noise

is it possible to use this engine in my cabrio loom wise and stuff

honest opinons please ??

[WillG]

Info you need for m50/52 swap is on this forum just search, you could try change rockers and shafts to help with noise there, they get worn after so many miles and have been known to break, new ones are abit beefier aswell.

[DanThe]

Would be possible yes but pointless as you would be reducing power.

The 2.5 M50's and above are the only ones worth bothering with

[Brianmoooore]

Would be possible yes but pointless as you would be reducing power.

The 2.5 M50's and above are the only ones worth bothering with

Not quite sure I agree with that, as a good M50B20's not going to be a lot down on a tired M20B25, and the fuel economy will be a lot better, and it sounds like the 2.0 litre is available.
Once it's up and running, it'll be a simple job to change over to the M50B25 if one comes along.

Engine wiring looms are separate, and stay with the engine. E34 one adapts easily to fit the E30 body loom.

[Doc-Dori]

cool !!

so my understanding is if i take the engine out of the 520i the engine has a seperate loom that stays with the engine and will fit straight into my e30

so what happens with my dails do the waork off a seperate loom ??

[WillG]

you need the ECU from same engine on later cars i aswell i think

[Brianmoooore]

you need the ECU from same engine on later cars i aswell i think

The ECU is wholly attached to the engine loom, both on the M20 and the M50.

[Brianmoooore]

cool !!

so my understanding is if i take the engine out of the 520i the engine has a seperate loom that stays with the engine and will fit straight into my e30

so what happens with my dails do the waork off a seperate loom ??

The engine looms connect to the car by a battery + and an earth, and the big C101 plug and socket mounted on the bulkhead just inboard of the fusebox. All the instruments will work fine.
It's not quite as straight forward as this, as the M50 loom has a physically different C101 plug, which needfs changing and you'll have to find somewhere for the ECU and DME relays to live.
Many on here have done it, including myself.

[WillG]

yeah but it can be detached so if he asked a breakers for a loom I doubt they would give him ECU aswell? and some of the later e36 ones need other bits to work aswell dont they?, expect this isnt the case on a old 5 series tho

[jmc330i]

you need the ECU from same engine on later cars i aswell i think

The ECU is wholly attached to the engine loom, both on the M20 and the M50.

If he means the later EWS equipped models then yes, the ECU, EWS module and ignition key all need to be a matching set from one car (not necessarily from the same car as the engine).

I didnt realise any E34s had the EWS system, but it would only be the '95 models if they did. My ETK is listing the EWS bits on the E34 520i (M50) from Dec '94.

[Doc-Dori]

whoa mad talk going on here havent a clue whats going on now

i know i have a e30 325i

and a full running bmw 520i with the 24v engine so have i got everything i need to do the swap or is there more bits required ??

[Brianmoooore]

whoa mad talk going on here havent a clue whats going on now

i know i have a e30 325i

and a full running bmw 520i with the 24v engine so have i got everything i need to do the swap or is there more bits required ??

You probably have all the electrical bits. I'm assuming it's a fairly early 24 valve.
From '95 onwards the electrics became orders of magnitude more complex, with the introduction of the EWS integrated immobiliser system.

[jmc330i]

whoa mad talk going on here havent a clue whats going on now

Sorry, it gets like that a bit.

i know i have a e30 325i

and a full running bmw 520i with the 24v engine so have i got everything i need to do the swap or is there more bits required ??

Basically yes, but I will let Brian answer that as he knows more about using the 5 series as a donor for the conversion.

Im not sure which prop you would need or if the 5 series engine mounts are useable, but having the complete donor car is a good start, so everthing else is easily sorted.

[Brianmoooore]

If the donor is a 520, then I would expect that the standard 325 prop can be used. Depends on what size the gearbox output flange is (there seems to be three flavours).
Alternatively, the E30 325 box can be used (with other minor problems to solve), but that saves having to change the diff.

[WillG]

sorry didnt realise the 520 was car being used, just an example of engine

[Doc-Dori]

hmm its not really worth doing by the sounds of things ... i was thinkin realiabilty wise using the 520i engine
maybe i should drop an sr20det 2.0 turbo 4cyl from japland in to it for the laugh make the engine swap worth while

[DanThe]

[stevetigger]