Preparing for s52 swap

[Tommyisfu]

Hello Everyone,

I am new to these forums but I just wanted to start right away with asking a few questions about an s52 swap into e30.

First quick intro to my situation. Unfortunately some old lady totaled my 96 m3. Luckily I will not have to get rid of my m3 entirely. My m3 is still salvageable and thought maybe s52 swap into e30 might be good.

So far I have done a bit of research but Im not completely sure what I may need and just want to get started with the process.

I still need to find an e30 and then order any parts I will need.

So questions begin:

1. Is there a recommended model e30 that i should look for?
2. Is there anything I should try to prep to get the ac system working?
3. What other than the s52 would be good to bring over from the m3 to the e30?
4. Any tips on what to do and not to do during this whole procedure?
5. Is there anything that has to be done about obdI or obbII

Im trying to avoid snags and be ready because I am trying to get this car running to use soon. But thanks in advance for the information.

(everything in engine bay is fine except the top half of radiator area)

[DesertBMW]

1. any e30 would do, but 1989-1991 coupe is the best one to get
2. all is needed are custom AC lines.
3. trans, shifter, driveshaft, radiator (rack and pinion optional)(seats optional)
4. many tips for that
5. needs to be programmed by me

[mtech325]

1. A late model e30 (88-91) will probably be the best platform to start with. If you get an 88' coupe/sedan with the diving board bumpers, the later plastic bumpers are a direct swap. I think a 325i(s) car is the better option as they more readily accept a 24v swap (better coolant tank setup, medium case differential. The 325 can even use its stock transmission and driveshaft if you want to use those parts.

A clean 318 shoudn't be discounted, but the the transmission and small case diff won't last long against an S52. The m42 318 radiator setup is also not ideal for the 24v motor, particularly in California, so you'll want to swap it over to a 6 cylinder radiator.

2. The A/C stuff I don't know in depth. Custom lines are needed, and the e30 is usually an R12 system that has to be converted to R134A, which can be pricey.

3. As DesertBMW has stated. the ZF320 transmission, shift linkage and driveshaft will be good things to move over. This is a good time to do the detent pin service if your transmission has the "5th gear lean." Might be worthwhile to keep the stock midsection and/or muffler if you liked the sound of your M3, but the exhaust will probably have to be chopped up a bit to fit on the e30. The e36's steering rack would be a good conversion for the e30 too while you have everything apart.

4. As for tips, I would say do as many "easy-while-out-of-the-car" jobs to the engine as you can. AKA gaskets, rear main seal, oil pump nut, etc. Find the best e30 shell you can, as a car that hasn't been hacked up over the years will make things a lot easier during the swap.

5. Since you have the entire donor car, OBD2 is very doable. If you want to make it CA BAR legal and OBD2, then you have to swap all the emissions equipment over, which can be more of a challenge, but you have better diagnostics. The OBD1 conversion is less involved, but you do need all the sensors off an OBD1 m50 and/or s50, along with the OBD1 wiring harness & ecu.