How is the 2.5L diesel?
- Thread starter Viggen
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Rovertrader
Supporting Sponsor
2.5 NAD is bombproof- but it has to be since it can't get out of it's own way. Very slow but gotta love 'em. I drove one in a 110 cross country, and it took forever....
gjackson
FRGS
Yeah, the 2.5NA was never stock in the Disco, so I'd questions the pedigree. If it is a 200 or a 300 then those were both stock in the disco. But there was no disco in 86, so that's kinda odd.
As a motor goes, the 2.5 is awesome if you want to go really slowly forever. And no, I doubt it would do 70 in a disco or anything else. Unless it was downhill with a pretty substantial tailwind.
cheers
As a motor goes, the 2.5 is awesome if you want to go really slowly forever. And no, I doubt it would do 70 in a disco or anything else. Unless it was downhill with a pretty substantial tailwind.
cheers
pangaea
Adventurer
I agree with the consensus on the 2.5 NA. It's bombproof, but slower than Christmas. I had one in a Defender 130... going up hill was painfully slow.
Although I haven't owned one, the 2.5 turbo diesel was apparently prone to overheating. If you want to go the turbo route, seek out either a 200 or a 300 since they don't have the same cooling issues.
Although I haven't owned one, the 2.5 turbo diesel was apparently prone to overheating. If you want to go the turbo route, seek out either a 200 or a 300 since they don't have the same cooling issues.
Antichrist
Expedition Leader
There were no Defenders, or D90's, in 1977, so it's probably a rebodied Series III, or Defender registered as a Series to get around some laws. No telling what the engine is. Post some photos of the engine if you can.
ExpeditionOz
New member
I've got a 2001 Disco 2 with the TD5 (2.5L Turbo Diesal) engine in it and i've stroked up nearly 200,000km (124,000 miles) across Australian deserts, through rivers that went half way up the windscreen, on sand dune covered beaches, cruised through sticky mud and driven up crazy angled rock laden mountains tracks and the engine has never overheated or under-performed even once 
larrynsr
New member
I have the NA 2.5 from a defender in my Series IIa. It's slow and not much power but it get's the job done....It's very simple to work on. Changed the timing belt in about 2 hours with the basic tools. The only thing I don't like about this engine is that it uses a timing belt. I wish it was gear driven instead.
Snagger
Explorer
Thjere's a lot of confusion in this thread, so I'll try to help clarify it a bit.
Discovery Is came with only four engines: the 200Tdi, superseded by the 300Tdi; the V8 and the 2l petrol Mpi, which was underpowered and slow, so very unpopular and a little rare. I don't know if the Mpi was even available for export outside the UK, and I'm sure they'd never have bothered with it on the US or African markets.
The 2.5 normally aspirated diesel, known as the 12J, was used in the earlier 90s and 110s, pre Defender. They were slow but very robust and reliable, with plenty of low down torque for an engine of its type. The UK forces stuck with this engine even while the 200Tdi Defenders were in production, only changing to a later engine when they introduced the TUL/TUM "Wolf" Defenders with the 300Tdi. They are not prone to overheating, and well cared for, are renowned for their longevity. The 12J was a stroked version of the 10J, which was what was fitted in the SII and SIII diesels. They used a 5mb crank with longer throw, a rubber/kevlar timing belt and a relocated Lucas CAV injection pump, but were otherwise very similar to the late 10Js.
The next engine after the 12J was the 19J, which was the same basic engine uprated to take a Garret turbo charger. They were prone to over-heating, and very prone to cracked heads and pistons. Early 19js also tended to crack blocks.
The 200Tdi followed on from the 19J, and share not only the general lay out but also many of the components, like crank shaft, flywheel, cam shaft, cam followers, piston oil jets and so on. Even the blocks are very similar. It was on the introduction of the Tdi that the 90/110/127 models became "Defenders".
The 300Tdi is a devopment of the 200, with several significant developments but still essentially the same core engine.
A 12J in a Series vehicle or a 90/110 is fine, if a little slow. It'd be awful in a Discovery, and would only fit after a lot of modification of both engine and vehicle.
Discovery Is came with only four engines: the 200Tdi, superseded by the 300Tdi; the V8 and the 2l petrol Mpi, which was underpowered and slow, so very unpopular and a little rare. I don't know if the Mpi was even available for export outside the UK, and I'm sure they'd never have bothered with it on the US or African markets.
The 2.5 normally aspirated diesel, known as the 12J, was used in the earlier 90s and 110s, pre Defender. They were slow but very robust and reliable, with plenty of low down torque for an engine of its type. The UK forces stuck with this engine even while the 200Tdi Defenders were in production, only changing to a later engine when they introduced the TUL/TUM "Wolf" Defenders with the 300Tdi. They are not prone to overheating, and well cared for, are renowned for their longevity. The 12J was a stroked version of the 10J, which was what was fitted in the SII and SIII diesels. They used a 5mb crank with longer throw, a rubber/kevlar timing belt and a relocated Lucas CAV injection pump, but were otherwise very similar to the late 10Js.
The next engine after the 12J was the 19J, which was the same basic engine uprated to take a Garret turbo charger. They were prone to over-heating, and very prone to cracked heads and pistons. Early 19js also tended to crack blocks.
The 200Tdi followed on from the 19J, and share not only the general lay out but also many of the components, like crank shaft, flywheel, cam shaft, cam followers, piston oil jets and so on. Even the blocks are very similar. It was on the introduction of the Tdi that the 90/110/127 models became "Defenders".
The 300Tdi is a devopment of the 200, with several significant developments but still essentially the same core engine.
A 12J in a Series vehicle or a 90/110 is fine, if a little slow. It'd be awful in a Discovery, and would only fit after a lot of modification of both engine and vehicle.
R_Lefebvre
Expedition Leader
FWIW, I was on some trails this weekend with a guy who had an ex-MOD 109 and a 2.5L diesel. He said it would only do about 100 km/h, but judging by his actual road speed, he was more comfortable around 70 because that's what he was doing on a road with 80kph limit. On the trail you'd never notice though. And he claimed, and it seemed to me to be true, that he had an easier time tractoring through some mud than another guy who was out there with a 110 TDi.
Snagger
Explorer
The 12J has a 23:1 compression ratio, compared to the Tdi's 19:1. Additionally, it breathes unrestricted, with a simple inlet and exhaust. The Tdi would suffer some breathing restrictions when at low revs, where the turbo isn't producing any boost and acting as a blockage instead. The 12Js seem, anecdotaly at least, to have more torque at low rpm than a Tdi, though once a Tdi reaches 1880rpm (peak torque), it'll be well ahead of the 12J. So, for rock crawling and steep descents, a 12J would probably be the better option.
Nonimouse
Cynical old bastard
The MPi was sold all over Europe and the UK with some going to the far East. It appealed to countries with a 2.0ltr tax band.
It uses the 134bhp 'T' series engine built by Rover and designed by Rover/Honda. This engine is unkillable abd revs to 6,800 on a good day - thanks to it's twin cam design. Once moving the Disco MPi was fine, but it lacked low down grunt.
I was lucky enough to drive a lightened competition MPi running the Turbo'd version of the 'T' series and the Roversport GEMS ECU. with 200plus bhp and an 8,000rpm redline it was a hoot
It uses the 134bhp 'T' series engine built by Rover and designed by Rover/Honda. This engine is unkillable abd revs to 6,800 on a good day - thanks to it's twin cam design. Once moving the Disco MPi was fine, but it lacked low down grunt.
I was lucky enough to drive a lightened competition MPi running the Turbo'd version of the 'T' series and the Roversport GEMS ECU. with 200plus bhp and an 8,000rpm redline it was a hoot