BMW E30 to M5x/S5x Engine Swap - Parts List

This list is not comprehensive, but it’s a good start when considering what must be factored in general.



Updated 6.Oct.2017


1. E30 radiator (only late will work (not early), as the reservoir is on the wrong side) or E36 part with the lower mounts raised
2. E30 radiator overflow tank
3. E30 M20 fan, possible w/clutch, however a SPAL electric fan on the other side of the radiator (removing the AC condenser and fan all together) can also be used

4. E28 533i motor mounts w/ 5mm spacers or e28 m5 mounts without spacers; AKG has some custom mounts
5. E34 throttle cable (35 41 1 160 609)
E21 brake booster with a modified shaft to 15mm or 325ix brake booster (or Porsche 944) or E32 735 part, without mod to the shaft. Additionally,
if the stock booster is used, drill holes 8 mm (1/4” in.) to the drive side to move the booster over for more clearance

7. E34 M5 or 25mm brake master cylinder w/ additional brake line used for the 325ix booster or an E32 735i part with the modified 320i booster
8. E30 325 transmission cross-member; Treehouse has a custom cross-member part for the E36 transmission
9. E28 m5 or two 320i trans mounts, whichever are cheaper; AKG has these mounts as well
10. E30 M3 driveshaft or the front of the E36 mated to the rear of an E30 M3 (should rebalance it); also can use an E36 ‘97+ Automatic driveshaft
11. E30 differential with a 3.25 ratio or E28 533i with a 3.25 LSD
E30 318 ECU mount
13. E34 parts:

§  E34, 525i oil pan (11131740346)

§  Oil sump gasket (11411703947)

§  Oil sump-suction tube (11411748150)

§  Dipstick tube (11431738169)

§  Dipstick (11431720875)

§  New dipstick o-ring (11431287541)

§  Small plate secure the dipstick to the front intake manifold bracket (must self-fabricate)

§  When using an M52 motor, the E34 dipstick will need to be modified to accept the different diameter crankcase vent tube

15. E36 m3 exhaust manifold - Turner Motorsport sells a custom header for US$950 specifically for this application (E30 to M5x conversion), Pelican sells the same for US$999
16. M50 radiator hoses
17. E36 Motronic (M3/325i/328i)
18. OBDI intake manifold
19. OBDI throttle body boot
20. E36 alloy mounting arms
21. Use the stock M50/S50 wiring harness – be sure of which ECUs utilize EWS or not
22. The engine harness and the ECU should be E36
23. The exhaust from the downpipe to the muffler will be custom



§  On the standard E30 with M20 engine fitted, you have the large round plug (C101) up on the firewall next to the brake booster

§  This plug has 2 parts. One half is connected to the car wiring, and the other is connected to the engine harness

§  When the M20 was removed, the engine side of the plug was removed with the engine. Now I have the S50 half of the plug in its place. Although similar in appearance, it will not plug directly into the E30 half of the plug.

§  I removed the E36 engine half of the plug, and replaced it with an E30 one. This then allows the 2 parts to screw back together. All you need to make sure is that you have the correct wires connected to each other. It’s not just pin 1 to pin 1 and pin 2 to pin 2 etc (although some of the wires do actually connect this way).

§  This plug connection is the only point where the E30 & E36 wiring interface with each other. The rest of the E36 engine harness is totally self-contained

§  Treehouse Racing custom adapter part ~US$400; however on Rv3limited, there are others selling plug-and-play adapters for $200; AKG is US$225

§  M52/S52 conversions: To go full ODBI (if desired), all the ODBI sensors will be needed, as well as the throttle body, spider hose, pcv valve for the valve cover- it may or may not be possible to use the S52 front cover as a place is needed to mount the cps. If there is a place, then it can be used. Need both knock sensors and other miscellaneous things

§  Parts list to convert from ODBII to ODBI

o    M50 Intake manifold

o    Intake rubber elbow

o    Red label ecu

o    ‘92-‘95 M50 harness

o    Crank and cam sensors

o    Knock sensors (2)

o    M50 fuel rail

o    02 sensor

o    MAF

o    Throttle body

o    Spider coolant hose

o    Valve cover (not necessary)

o    coils (no)

o    timing cover case (no)

o    Coolant temp sensor (Will need to tap head for e30 gauge sensor)

o    PCV (possible to use modified obd2)