BMW M52B30 3.0 Inline-Six Petrol Swap
Donor: BMW M52B30 (E36 328i / E39 528i / Z3 3.0)
The affordable petrol six. 231bhp / 300Nm of naturally-aspirated Vanos inline-six from the E36/E39 platform, dropped into a Defender with a lightweight OBD2 loom and a Getrag 250 manual. Cheaper donor than an LS3, smoother than a Td5, and easily standalone-tuned.
ECU Solution
BMW MS41.1 (single-Vanos) or MSS52 (double-Vanos), or Emerald K6 / MegaSquirt MS3-Pro standalone.
Gearbox Options
BMW Getrag 250G manual with R380/LT230 adapter, or ZF 5HP18 auto.
Compatible Models
Defender 90 · Defender 110 · Defender 130
Later M52TU (post-1998) uses double-Vanos and requires MSS52 or standalone tuning. Verify Nikasil vs Alusil bores on early US-market blocks.
Step-by-step guide
5 steps- 0101StepCritical 1 day
Source and inspect the donor M52
Buy a running E36 328i or E39 528i donor rather than a bare engine. Compression-test all six cylinders, pull the valve cover to check for sludge, and inspect the Vanos rattle. Reject Nikasil blocks (early 1995–96 US) unless bores are verified.
ToolsCompression tester, Borescope, OBD2 reader
PartsDonor vehicle (running)
- 0202StepCaution 2 days
Fabricate engine mounts and gearbox crossmember
M52 sits ~40mm further back than the Td5. Fabricate tubular mounts off the block ears to the chassis outriggers, and a new crossmember for the Getrag 250. Verify prop-shaft angle stays under 3°.
ToolsMIG welder, Angle finder, Engine crane
Parts4mm mild steel plate, Poly bushes, Getrag 250 crossmember
- 0303StepInfo 1 day
Adapt the gearbox to LT230
Fit an Ashcroft or GwynLewis Getrag-to-LT230 adapter plate with a machined input shaft. Torque bellhousing bolts to 45 Nm.
ToolsTorque wrench, Alignment tool
PartsGetrag-to-LT230 adapter, Spigot bearing, Clutch kit (BMW 240mm)
- 0404StepCritical 2 days
Standalone loom and ECU
Strip the donor loom of body/CAN wiring. Program MS41.1 with EWS-delete, or fit an Emerald/MegaSquirt standalone. Wire relay pack behind glovebox.
ToolsMultimeter, Soldering iron, INPA/NCS Expert
PartsStandalone loom, ECU (MS41 or MS3-Pro), Relay pack
- 0505StepCaution 2 days
Cooling, exhaust, and commissioning
Fit a Puma 2.4 rad or 40mm alloy uprated core with dual electric fans on a thermostat switch. Fabricate a 63mm stainless downpipe merging into a 76mm system with a high-flow cat. Prime, bleed, base-map, then dyno.
ToolsDyno access, Coolant vacuum filler, Exhaust jig
PartsUprated radiator, Dual electric fans, 63mm stainless exhaust
M52 Swap · Suppliers & Lead-Time Board
Vendors that ship the parts an M52B30 Defender swap actually needs: donor sourcing, adapter plate, standalone ECU, and cooling.
| Vendor | Scope | Indicative price | Lead time | Stock | Shipping | |
|---|---|---|---|---|---|---|
GwynLewis 4x4 UK · Essex | M52/M54 → LT230 bellhousing adapter + custom crossmembers Long-standing BMW-to-Defender swap specialist; will fabricate on request. | £850 – £1,150 | 4–6 weeks | Made to order | Worldwide freight | Visit → |
Ashcroft Transmissions UK · Dunstable | Getrag 250-to-LT230 adapter + machined input shaft | £780 – £1,000 | 3–5 weeks | Made to order | Worldwide courier | Visit → |
Emerald M3D UK · Norfolk | K6 standalone ECU + M52-specific base map The pragmatic OBD-free path. Preferred if you want to delete EWS/DME entirely. | £1,100 – £1,450 | 2–3 weeks | In stock | UK/EU tracked | Visit → |
DIYAutoTune (MegaSquirt) USA · Georgia | MS3-Pro Ultimate standalone ECU + M52 harness kit Cheaper than Emerald if you're comfortable with TunerStudio. | £1,250 – £1,600 | 1–2 weeks | In stock | DHL worldwide | Visit → |
Schmiedmann Denmark · BMW parts | Running M52B30 donors, looms, DMEs, Vanos units Reliable donor sourcing with photos and mileage stated. | £800 – £1,800 (donor) | 1–3 weeks | In stock | EU pallet, worldwide freight | Visit → |
Pelican Parts USA · CA | M52 service parts: Vanos rebuild kits, gaskets, cooling | £15 – £450 per line | 1–2 weeks | In stock | USPS/DHL worldwide | Visit → |
Allisport UK · Devon | Alloy uprated radiator + intercooler cores for Defender bay M52 runs hotter than Td5 — an uprated core is not optional in warm climates. | £420 – £680 | 2–4 weeks | Made to order | UK/EU pallet, worldwide by quote | Visit → |
Turner Motorsport USA · Amesbury MA | BMW performance parts: clutch kits, exhaust, cooling | £100 – £900 per line | 1–2 weeks | In stock | Worldwide | Visit → |
M52/M54 → LT230 bellhousing adapter + custom crossmembers
Long-standing BMW-to-Defender swap specialist; will fabricate on request.
Getrag 250-to-LT230 adapter + machined input shaft
K6 standalone ECU + M52-specific base map
The pragmatic OBD-free path. Preferred if you want to delete EWS/DME entirely.
MS3-Pro Ultimate standalone ECU + M52 harness kit
Cheaper than Emerald if you're comfortable with TunerStudio.
Running M52B30 donors, looms, DMEs, Vanos units
Reliable donor sourcing with photos and mileage stated.
M52 service parts: Vanos rebuild kits, gaskets, cooling
Alloy uprated radiator + intercooler cores for Defender bay
M52 runs hotter than Td5 — an uprated core is not optional in warm climates.
BMW performance parts: clutch kits, exhaust, cooling
Independent shortlist. Defender101 is not affiliated with any listed vendor. Confirm pricing, stock, and shipping to your region on the vendor's own site before ordering — VAT, duties, and lead times shift frequently.