Paddy Posted March 17, 2007 Share Posted March 17, 2007 According to Calvin my Vin number indicates 'C Engine type: 2.5 litre diesel (model 12J)' but a round disc on the rocker box reads 'Engine "Type Mk 6B"' Whats the difference and what is the tag "Type Mk 6B" trying to tell me? Regards Quote Link to comment Share on other sites More sharing options...
Guest dew110CSW Posted March 17, 2007 Share Posted March 17, 2007 12J is the Naturally Aspirated Diesel, The 6B bit I don't understand. Quote Link to comment Share on other sites More sharing options...
Paddy Posted March 17, 2007 Author Share Posted March 17, 2007 12J is the Naturally Aspirated Diesel, The 6B bit I don't understand. It is a N/A. What I didn't mentione, because I didn't think it was relevant, is the fact its ex Miliatry. Do you think its some military coding? Thanks Quote Link to comment Share on other sites More sharing options...
western Posted March 17, 2007 Share Posted March 17, 2007 MK6B would be the old army way of identifying engines, the engines own serial number should start with 12J, which is a diesel naturaully aspirated 2.5litre unit. Quote Link to comment Share on other sites More sharing options...
Pyrover Posted March 17, 2007 Share Posted March 17, 2007 I'm not sure about this... but in the Military Supplementary Parts Catalogue it lists the vehicles under a contract number, the catalogue I have is from September 86 and the vehicles listed start from 12A up to 28B so you may find that 6B is a contract number for the vehicle or the engine; is your Land Rover pre 86? Quote Link to comment Share on other sites More sharing options...
Paddy Posted March 18, 2007 Author Share Posted March 18, 2007 I'm not sure about this... but in the Military Supplementary Parts Catalogue it lists the vehicles under a contract number, the catalogue I have is from September 86 and the vehicles listed start from 12A up to 28B so you may find that 6B is a contract number for the vehicle or the engine; is your Land Rover pre 86? Sorry I seem to keep with-holding bits of info, I should have given you all the details in the first place, just didn't think it would be relevant. Ex military 1991 Defender 90 Hard top, 2.5 N/A. Thanks for your patience Quote Link to comment Share on other sites More sharing options...
Pyrover Posted March 18, 2007 Share Posted March 18, 2007 1991... ok that seems to have pi$$ed on that explanation then, although it's still possible that it's a replacement engine from an earlier contract. Looking at the 1991 parts catalogue it lists the 2.5NAD as 11J and not 12J, what's the number stamped on the block? Quote Link to comment Share on other sites More sharing options...
western Posted March 18, 2007 Share Posted March 18, 2007 EPC & my geniune 110 1987 on parts book says 12J is a 2.5n/a diesel, a 11J could be the early version of the 2.5n/a diesel prior to the intro of the 200Tdi. Quote Link to comment Share on other sites More sharing options...
Ex Member Posted March 18, 2007 Share Posted March 18, 2007 Actually, a lot of the later NA engines are actually TD blocks. Have a look on the left hand side to see if there are ports for the turbo oil feed. My ex engine was this way and I had the Mk 6B tag and it was a 1991 model. Quote Link to comment Share on other sites More sharing options...
Ex Member Posted March 18, 2007 Share Posted March 18, 2007 Look for the large plug next to the dipstick. Quote Link to comment Share on other sites More sharing options...
Paddy Posted March 18, 2007 Author Share Posted March 18, 2007 Thanks for all your interest. Embarrassed to say as I have only just got the 90 I haven’t even got the engine number yet. Here in Ireland its blowing a northerly blizzard and the truck is outside with no cover for half a mile!! so I’ll check for the turbo oil feed plug and get my ass into gear and get the engine number tomorrow. Red, I’m encouraged to hear that you had a similar setup with year and 6B tag, you could be on the right track. Perhaps you gents would be so kind as to have a look here tomorrow. Regards Quote Link to comment Share on other sites More sharing options...
western Posted March 18, 2007 Share Posted March 18, 2007 I'm sure we will Quote Link to comment Share on other sites More sharing options...
Paddy Posted March 19, 2007 Author Share Posted March 19, 2007 Well the snow has disappeared so out to the truck to check engine details, which is a bit of a shame as I fancied having a drive around in the snow. Western & Pyrover: My engine number is 11J00986A. Number is stamped ‘above the rear side cover’ Red: my engine appears to be identical, (even down to the same colour and same Mk6B tag) to your photo with the large plug slightly above and to the right of the dipstick. So looks like you have the answer. Again thanks for every ones help. I’m sure more questions will follow as I get into giving the girl some TLC. regards Quote Link to comment Share on other sites More sharing options...
Pyrover Posted March 19, 2007 Share Posted March 19, 2007 I'm glad that seems to have solved that problem, but it's probably not a good idea to post your engine number up on the forum, you never know what nefarious characters are reading this stuff. Quote Link to comment Share on other sites More sharing options...
headdamage Posted March 24, 2007 Share Posted March 24, 2007 I've got Red90's old engine in the above pic and it is an 11J as well. I wonder why they are not 12J or 19J? Untill now I'd never seen an 11J. Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted March 24, 2007 Share Posted March 24, 2007 10J 2.25 diesel 5 bearing 11A 2.4 VM TURBO D 11J 2.5 N/A DIESEL MOD 11L 2.5 TDI DIESEL (200TDI) 17H 2.5 PETROL 12J 2.5 DIESEL N/A 12L 2.5 TDI (DISCOVERY) 14J 2.5 DIESEL FREIGHT ROVER 15H 2.5 DIESEL CARBODIES (LONDON CAB) 15J 2.5 DIESEL FREIGHT ROVER 19J 2.5 TURBO DIESEL 90/110 22J 2.5 TURBO DIESEL FREIGHT ROVER Quote Link to comment Share on other sites More sharing options...
headdamage Posted March 24, 2007 Share Posted March 24, 2007 Thanks for the list Quote Link to comment Share on other sites More sharing options...
headdamage Posted March 27, 2007 Share Posted March 27, 2007 Does anyone know if all of the 11J's are dilled and tapped for the turbo oil feed and drain? If so why? Are they 19J blocks with just a different serial number for the military? Thanks. Quote Link to comment Share on other sites More sharing options...
western Posted March 27, 2007 Share Posted March 27, 2007 Possibly LR used excess 19J TD blocks on various n/a engined vehicles as it had been upgraded around 1986/87 before the TDi came on stream, use up the old stuff before fitting the new engines Quote Link to comment Share on other sites More sharing options...
MoD90 Posted February 6, 2017 Share Posted February 6, 2017 I think I'm correct in saying that a round metal disk on the rocker cover is the Military way of denoting that the engine has been modified in some way. In my case the disk bore the stamps of AMRO, the work contract number, and the individual job code. This particular engine had also been repainted duck egg blue, as an additional quick identification of a reconditioned engine. The purpose, obviously, to alert the military mechanics that they're not dealing with a standard NAD 12J. In my example, the original engine number had also been ground away. Have fun, MoD90 Quote Link to comment Share on other sites More sharing options...
Cchase Posted February 6, 2017 Share Posted February 6, 2017 (edited) My 12J is also an Ex MOD 110 LHD from the British base in Alberta, Canada. It has the same tag on the rocker cover as well as this re-manufacture tag. I'm still not sure what the Mk. 4/6B is all about. Cheers, Colin Edited February 6, 2017 by Cchase Quote Link to comment Share on other sites More sharing options...
neil110 Posted February 6, 2017 Share Posted February 6, 2017 (edited) If you look in this thread there is a link to a list of military Land Rovers. If you then read the details of the 2nd vehicle on the list it is referred to as a Land Rover Mk 6B as are others in the same document. Although that 2nd vehicle listed is quite interesting in that it had the R380 gearbox fitted in 1990. Whereas it was not fitted to Civilian Land Rovers until they were fitted with the 300Tdi in 1994 Whilst a bit like reading the phone directory there are some interesting vehicles on the list Edited February 6, 2017 by neil110 Quote Link to comment Share on other sites More sharing options...
Snagger Posted February 7, 2017 Share Posted February 7, 2017 The 19J had bigger bearings than the 12J, as well as the oil galleries for the turbo charger. The 12J gave way to the 19J on civilian markets, but the MoD didn't want it (evidently they did more rigorous trials than LR), so a 2.5 nad continued to enter service until the 300Tdi with the TUL and TUM "Wolf" and "Pulse" vehicles. That nad was made using the 19J block, bearings and crank shaft with 12J externals, rods and pistons (12J has 23:1 cr while 19J has 21:1, so 19J parts are not good for nad). Given that these were no longer fully 12J spec engines, redesignation was necessary. I suspect the Mk6B tags are to draw attention to the difference for REME mechanics as the engine looks very similar to the 12J and confusion in parts fitting could occur. Quote Link to comment Share on other sites More sharing options...
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