12JXXXXXC ENGINE CONFUSION CALLING EXPERTS

[KIDD67]

Hi All

I already touched on this problem on our Facebook site, but I'm still not satisfied with the answer. NO OFFENSE to the information I received on the matter it is very good and helps. But there is still the why and what.

Basically in a nutshell I have an ex suffield mod defender. The engine in it is serial number 12J35415C Yes a standard squaddy mod 2.5 NA Non turbo. It's also a Refurbished for mod standard green lump.

I also have a spare engine serial number (MK 2/3 ?? 12J21401C). Now I got this engine from the big fella (John a brit) in Salmon Arm BC. He was a land rover guy from way back and recently sold all his stuff. Anyway he said he got this engine out of an ex mod "Wainwright AB" Defender and had kept it because it was a different sort. I guess he meant different as it was original factory paint (orange with unpainted aluminium valve cover) So my assumption is this engine was installed at factory for mod and he got it before that particular unit was rebuild? correct? possible?

Anyway this engine does not have the CVV sump take off to oil separator like the green unit in my defender does. I was told that all mod defenders had to have that modification.

Is it possible that the spare orange unit (see photos) is one of the earliest 12J blocks that mod had in its defenders and they originally came without the oil separator modification?

If not then what is this engine exactly.

Regards.

1. PIC IS THE ORANGE PAINTED BLOCK?
2. PIC OF THE ORANGE BLOCK SERIAL NUMBER SHOWING MK 2/3?
3. PIC OF THE SUMP FROM ORANGE BLOCK ENGINE, NOTE NO TAKE OFF FOR OIL SEPARATOR?
4. PIC OF THE SUMP FROM GREEN BLOCK, NOTE YES THERE IS A TAKE OFF FOR AN OIL SEPARATOR? I WILL SAY ONE THING. THE SOLDERING JOB ON THAT SUMP TAKE OFF CERTAINLY DOES NOT LOOK LIKE FACTORY. MAYBE AT TIME OF REFURB FOR MOD THAT WAS WHEN MOD ORDERED THE OIL SEPARATOR MODIFICATION?? PERHAPS AFTER SOME SQUADDY CRATERED HIS ENGINE BY ADDING TOO MUCH OIL?? ANY REMMIES HERE HEARD OF THIS??

[Matt H]

You can drive yourself crazy trying to pin down what was a "standard" specification for MOD Land Rovers. Every time you think you have it you will see one that is different.

MOD Land Rovers were often moved around from unit to unit and even from Arm to Arm. I was in Armoured Regiment and we had an ex RAF V8 110 truck cab as a parts runner. Nearly all MOD Units  had different requirements and most of the confusion comes with at what point the vehicle was deemed complete and ready to be sent to its Unit. As delivered from the factory? As delivered to the Unit? As used in its final role? So the question of the sump modification is equally as difficult to pin down. There may be a date when the modification was deemed nesassary? Most likely it was a rebuild rolling upgrade that was introduced as engines were replaced as a superseded part.

Certainly the orange block engine is orginal from factory and I have seen replacement engines go in place of these that differ from the stock units. Army Rebuilds were often of dubious quality though. The orginal unit will have been manufactured to a higher standard.

[headdamage]

For a number of years the vast majority of the 90/110 engines that come out of suffield and wainwright did not have the oil scavenger modification.  They vented the crankcase directly from the valve cover to the inlet muffler of the air cleaner. This resulted in many short lived air cleaners, hence the modification.

[KIDD67]

Yeah I guess its an exercise in futility. Any idea what the mk 3/4 means?

[ugly_90]

The MK 2/3 was the addition of oil cyclone separator. Your engine may not have it, as the green paint blocks were abro rebuilds, and could have been parted with something else. The red blocks, knowing that you didn't pick them up from meticulous dealer service, could have had any history, but likely never went to Abro.

there are only three variations of military 2.5NA, all engines use "air conditioning" parts, as they are uprated, and all have no A/C compressor.

-12J early, without oil separator.
-12J mid, MK 2/3, with oil separator.
-11J late, turbo-capable block, uses oil seperator, later crankshaft,  and injectors. Improved head design (STC803). My 1995 11J even uses later 10mm heads on most bolts. This is in keeping with LR changes in that era.

You should be pursuing rebuild of 11J blocks when available. They are marginally better, parts are more available. I haven't found a block yet with perfect bores and perfect cam bearings, a bit of a unicorn to find this. Several sleeves can be slipped, cracked, or worn.

You'll have to start there on a stripped block. The only two discount machine shops we've found are in Westlock and Calgary.

New cam bearings have to be line-bored in the block, and require a specialized shop to do this. Prefinished bearings will not readily fit.