Thread: V8 Engine Identification

Ok the engine is a 3.9 out of a D1 - the 3.9 was not in the D2 so if you have the ECU from a D2 4.0 it is not the correct one.

You need a 4CUIX ecu and the comp ratio should be 9.35:1 if Hi Comp - will be above the engine number on the pad on the left side of the engine where the dip stick goes into the block.

Gems was on the early 4.0 and 4.6 engines.

Garry

I can't find 56D on any lists, you sure it's not 36D? Anyway, it looks like a late D1 3.9 engine. The best engine harness and ECU to find are off a '91 to '93 Range Rover 3.9, they are a stand alone harness that only does the EFI. It's also quite long and puts the ECU and relays under the drivers seat. You'll need to graft it to the engine loom you have as it has some different locations for sensors and plugs, not particularly hard as the colours should be the same. If you get a Range Rover harness you only need engine block earth, battery positive, ignition positive, coil negative and fuel pump connections and it will run. Speed sensor input to the ECU can be ignored.

G`day ,

56D is a 4.0ltr post 2000 Discovery 2 the odd ratio will be right the lower comp is 8.23 , what you have is 14CUX .

I`d guess that the block and maybe heads are from a 4.0 D2 the rest is from a 3.9 D1 or softdash Range Rover .

Thanks for the fast response Garry, much appreciated.

Still a little confused though.

Going through the LR number it says that the 56D should have been in the D2 as a high comp motor. But the fuel injection system looks like a D1 as you stated.

The bloke who sold it to me did say it had been rebuilt a few years ago so maybe they used a newer block and heads (has the 10 bolt heads but have not pulled the sump to check the mains), is the 14CUX system compatible with later block/heads?

on the block it’s showing 9.38:1 which is odd but not a big issue as will check all that when its apart.

Just confirm its the 14CUX not CUIX? Can’t find anything on the second one.

Cheers

The block would have come from the factory with Thor/Bosch injection .

And more responses, thanks PLR and Bee Utey for the info.

Confirmed it is a 56D. Took lots of searching to find the right site that listed it as most don’t have it as an engine number.

As I said the bloke said it had been rebuilt so having the 14 CUX kit on the later block and heads makes sense I didn’t realize it would work though.

Also thanks for the heads up on the best loom to get. The longer the better as i need to get as much into the cabin as I can as the engine bay in the MGB will be too hot for the ECU to live there. Conversion manuals suggest having the ECU writing loom as a separate fuse box so you can run all new wiring and not try and integrate it into a 45 year old MG wiring loom.

Am sure I will have lots more questions during the rebuild. Thanks for your help so far.

my D2 engine was: Engine Number: 56D57753

which was a d2 high comp engine,

All the push rod LRV8's are backwards compatible, any later engine can be fitted with earlier running parts. A 56D 4.0 block should have cross bolted main bearings and the bolts will be visible externally above the sump line. Not that there's anything special about a 56D block, the cross bolting was fitted to allow the later blocks to function as 4.6's with the right crank and rods.