S50B32 Euro M-Powered 240Z Build

Datsun 240Z

Datsun 240Z (S30)4-page write-up

S50B32 Euro M Powered 240

Read the full write-up at S50B32 Euro M Powered 240 ↗

A 1970 Datsun 240Z being converted to BMW S50B32 M-power

Forum member katokid is swapping a Euro-spec BMW S50B32 straight six from an E36 M3 into a 1970 Datsun 240Z, working through engine mounts, clutch hydraulics, driveshaft, fuel tank, exhaust and electrical systems. The thread documents years of detailed fabrication work, bearing and sensor repairs, and problem solving to fit a modern EFI/Vanos engine into the vintage chassis.

Specs

As stated in the original write-up.

Engine: BMW S50B32 (Euro M3) straight six
Rear axle: Nissan R200 differential
Sump: S50B30 sump used for steering rack clearance

Parts used

Parts named as used in the original write-up, grouped the way the Parts page groups them. Where one of the shops we index lists the same thing for this car, it is shown underneath with a link to the shop.

Engine 3

BMW S50B32 engine
Euro-spec M3 engine swapped into the 240Z
ACL Race Series big end bearingsBursons
Fitted to the engine bottom end with pistons still in block
In the shops
Tri-Metal Big End Bearings 4 Cyl TR (+0.030") ↗TRGB· £65.95 GBP
Tri-Metal Big End Bearings 4 Cyl TR (+0.020") ↗TRGB· £65.95 GBP
Tri-Metal Big End Bearings 4 Cyl TR (+0.010") ↗TRGB· £65.95 GBP
ARP rod bolts
Fitted along with the big end bearings

Fuel & Ignition 2

Refurbished fuel tankMelwide Radiators
Original fuel tank cut, cleaned, tinned and modified for a new fuel module
K&N air filterK&N
Fitted to match the 92mm MAF sensor after factory airbox would not fit

Cooling 1

VAC Motorsport oil cooler kitVAC Motorsport
Used for engine oil cooling to improve reliability
In the shops
Paco Motorsports 3" Suspension Lift Kit ↗Flyin' Miata· $289.00 USD
P&L Motorsports CNC Exhaust Head Flanges ↗JDMuscle — Mazda MX-5· $109.95 USD
IL Motorsport Competition Engine Mount Pair ↗Flyin' Miata· $149.00 USD

Gearbox & Drivetrain 2

Shortened tailshaftKnox Driveshafts
Custom shortened tailshaft using BMW guibo joint front and BMW CV joint rear with R200 adapter
Nissan R200 differential
Used as the rear axle with an adapter to mate the BMW CV joint
In the shops
R200 Differential Cover Gasket ↗JDM Car Parts· $50.00 USD
R200 Differential Mustache Bar ↗JDM Car Parts· $498.00 USD
R200 Differential Side Seal Set ↗JDM Car Parts· $59.00 USD

Brakes 1

Clutch hydraulic linesBetter Brakes
Two sections of clutch line made up to connect master cylinder to slave cylinder
In the shops
Clutch Hydraulics ↗MGOC Spares· £27.80
Clutch Hydraulics ↗MGOC Spares· £27.80
Hydraulic Clutch Conversion Kit ↗Moss Europe (UK)· £206.75 GBP

Electrical 1

BMW genuine cam position sensorsPelican Parts
Replaced both inlet and output cam sensors to clear fault codes
In the shops
Penrite Cam & Engine Lube ↗TRGB· £13.15 GBP
Injector Lead O-Rings (Positions 2 & 5) ↗TRGB· £1.76 GBP
Hitachi 240Z Throttle Position Sensor Adapter Kit ↗pattonmachine.com· $159.99 USD

Photos

2 pictures collected from the write-up, in the order they were posted, shown from S50B32 Euro M Powered 240. A picture opens larger here, with the way through to the page it is on.

How it was done

Starting the swap

Inspired by the S54 engine in an E46 M3, katokid planned a BMW engine swap into his 1970 240Z, choosing a Euro-spec S50B32 to keep a naturally aspirated six. He consulted another builder, RTz, for mounting guidance and sourced engine mount brackets to begin fitting the M50-derived block.

Mounts, sump and exhaust fitment

Work covered fabricating a custom rear engine mount, confirming sump clearance against the steering rack, and checking whether the factory stainless headers would clear the chassis. A test stand was built from an M3 front crossmember to run the engine before installation.

Clutch hydraulics and driveline

Significant effort went into designing a working clutch master/slave cylinder setup using BMW parts adapted to the Z pedal box, sourcing hard lines from a wrecker. A shortened tailshaft was built by Knox Driveshafts using BMW guibo and CV joints with an adapter to the R200 pinion flange.

Engine refurbishment and electrical

After running the engine on a test stand, fault codes led to replacing both cam position sensors with genuine BMW parts from Pelican Parts. Big end bearings (ACL Race Series) and ARP rod bolts were fitted. Wiring harness repackaging and electrical work including a dedicated circuit were also completed.

Fuel, cooling and exhaust detail

The fuel tank was cut, cleaned, de-rusted and modified at Melwide Radiators for a new fuel module. A dual-pipe stainless exhaust system was planned to preserve the BMW engine note while meeting noise limits, and a power steering cooler was added due to known overheating issues.

Progress so far

As of the latest supplied posts, the car has a complete driveline from engine to wheels, ongoing bodywork and rust repairs, and ongoing small fitment tasks before the shell is sent for final paint. The build remains unfinished in the material supplied.

A summary in our own words. The full account, with all its detail, is in the original write-up: read it at S50B32 Euro M Powered 240 ↗

Worth knowing

BMW cam position sensors are far cheaper sourced from Pelican Parts than from a local dealer
Dual-pipe exhaust layout is needed to keep the BMW engine note rather than a single large pipe
Bearing shells sold under BMW branding are rebranded ACL Race Series bearings