GMC 6.2/6.5 V8 diesel?

[Guest diesel_jim]

Are these engines as inherantly unreliable as people say?

I was chatting to a chap t'other day, who has a rebuilt RR classic 2 door (it looked really tasty actually), with a 6.2 non turbo lump in it. sounded sweet, and went well too.

Now, i'm thinking about my *next* project, probably be a 130" double cab/hicap jobbie, and i reckon a 6.2 or 6.5 V8 would push it along rather well.

Has anyone got experience with these engines? i'll try (if i do the project) and get the proper gearbox for it (i think it;s the NV4500 which will mate to an LT230), but was wondering a) are they reliable, B) where do you get them from in the UK, and c) what are spares like?

any ideas folks?

cheers! B)

[GBMUD]

Are these engines as inherantly unreliable as people say?

I was chatting to a chap t'other day, who has a rebuilt RR classic 2 door (it looked really tasty actually), with a 6.2 non turbo lump in it. sounded sweet, and went well too.

Now, i'm thinking about my *next* project, probably be a 130" double cab/hicap jobbie, and i reckon a 6.2 or 6.5 V8 would push it along rather well.

Has anyone got experience with these engines? i'll try (if i do the project) and get the proper gearbox for it (i think it;s the NV4500 which will mate to an LT230), but was wondering a) are they reliable, B) where do you get them from in the UK, and c) what are spares like?

any ideas folks?

cheers! B)

I know a guy who had one in a Rangie. If he hit the throttle too hard he could break axles on the road. For me that makes it a non-starter - especially when coupled with the enormous weight.

Chris

[western]

IIRC Samuri were one of the importers of these monster lumps & I'm sure Tony Cable had one in a green 110sw.

[BogMonster]

From what I have read about them it appeared that the problem may not really have been the engine itself, but the people who put them together and sold them in this country ... allegedly

Curiously, said company whose name I won't mention (but it might appear above) had big shiny adverts in all the mags, a bit like another present-day company whose customer backup perhaps leaves a little to be desired

I think it is the same basic engine as the Hummer has in it and presumably that vehicles wouldn't have won the military selection trials if the engines blew up every 5 min? just my thoughts

[Andy]

im sure ive seen pics of one of these engines in a Ibex, cant remember whos though.

[Guest diesel_jim]

I know a guy who had one in a Rangie. If he hit the throttle too hard he could break axles on the road. For me that makes it a non-starter - especially when coupled with the enormous weight.

Chris

I'd start with Salisburies at each end, so that should help a bit, and maybe Mr Ashcrofts finest baked CV's.

Good point BM, if the 'mericans use them for rapid reaction coke delivery, then they must be pretty good.

Hmmm.... 130" 6.5 turbo..... or maybe a 110 instead for that extra "sportyness".... B)

[will_warne]

Jim, speak to Maddison 4x4, they do a lot with these engines and know how to make them work. A little word with Neil Redpath (yellow and green Ibex with supercharged 6.2) is also probably a good move. I know he had his engine built up in the states but it wasn't cheap.

From what I understand they do work well as an engine but they're an expensive option and not that ecconomical. I'd personally go on the hunt for a TDV6 and box; I don't think it'll be any more expensive and as your good with wiring.......

[BogMonster]

Ibex with supercharged 6.2

ooOOOoooh Kleenex

[western]

go on the hunt for a TDV6

spotted TDV6 on ebay last week

[Reno]

I stripped and put a few of thses engines together for a company in the mid 90s. You get what you pay for, good engines are great

cheat engines are often the leftover bits that are just in spec, assembled as a cheap unit. They know you will go back for spares.

They are still one of the best sounding V8s with the right pipes

[Astro_Al]

Personally, I just don't think these engines are on the right scale for a land rover. Too heavy.

Apart from that, I've just bought an NV4500 from the states (that'll make you project even heavier...) and they're not cheap - esp with shipping etc, could turn out to be a real high-dollar project.

Just a thought... Al.

[Guest diesel_jim]

Hmmmmm........

"pop".... the sound of my idea-bubble bursting.....

Maybe i'll just polish my 90 instead, it'll be cheaper!

[bill van snorkle]

Personally, I just don't think these engines are on the right scale for a land rover. Too heavy.

Apart from that, I've just bought an NV4500 from the states (that'll make you project even heavier...) and they're not cheap - esp with shipping etc, could turn out to be a real high-dollar project.

Just a thought... Al.

They may be heavy in comparison to an alloy Rover V8, but they compare favourably with an Isuzu 4 BD1 which was the Australian Deisel option for LWB LandRovers from around 1980 to 1990.

There are a few 6.2 and 6.5 Gmc converted Rovers running around over here and they seem to be reliable enough, although 22 mpg seems to be about the best fuel economy one can realistically expect.

Rovers LT95 transmission will live behind one, but no other Rover built box will. The NV 4500's are ok , expensive, but far from bulletproof. A mate of mine has a 6.5 with a Hino 6 speed truck box in his 2A LWB.

I have a four speed Warner T98 truck gearbox $200 good used)plus 2 speed Ranger torque splitter box (Another $200 used)which is much stronger and more versatile than the NV4500, that I was going to put behind a 6.2 but ,I am planning on moving to Vietnam in a couple of years, so I have decided to bolt it to a 3 litre normally aspirated Toyota Deisel instead.

Bill.

[nas90]

I know a guy who had one in a Rangie. If he hit the throttle too hard he could break axles on the road. For me that makes it a non-starter - especially when coupled with the enormous weight.

Chris

Chris, I know the Rangie and I know the driver and whatever the vehicle (Darren) would always break or drown the damn thing on every trip!

In the right hands with some mechanical sympathy it will probably be a good engine!

[Bush65]

All but the last of the 6.2 are prone to cracking the centre 3 main bearing webs from the outer bolt holes for the main bearing caps. The castings were beefed up when manufacture of the 6.5 started. This block (casting no 10149599) was used by both 6.2 and 6.5 in 1992-93 (6.2 was not produced after 1993).

Piston oil spray cooling was introduced in 1996, and the 1996-99 were prone to cracking the webs due to machining for the spray nozzles. This was solved by better metallurgy in later engines produced by AM General for Hummers.

They crack heads, but can be fixed by reaming water passage and fitting a sleeve (doesn't repair crack, but stops the leak). Caused by pockets of steam forming in the rear of the heads. This was eventually cured by fitting a high volume water pump (which could flush out the steam). These pumps can not practically be retrofitted to earlier engines because the rotate in the opposite direction (serpentine belt).

The vee belts have a reputation for short like - only Gates belts are recommended.

They tend to break the starter housing, if the extra support bracket is missing.

Their firing order causes impulsive torque loads which cause problems with the harmonic dampener. If the crankshaft bolt is not torqued properly, they flog out the keyway in the crankshaft. When the rubber element (of the dampener) degrades (replace dampener if the rubber shows signs of bulging out), they are prone to breaking the crankshaft.

The torque impulses would show up weakness of lightweight gearboxes (like LT77).

The best of the injection pumps was the non-electrical controlled DB2-4911 fitted to the 6.5 in 1993. The later electic controlled pumps (DB4) have a reputation for poor life. this pump with Lucas/Delphi injectors for the 6.5 will give worthwhile performance improvements when fitted to a 6.2 engine.

There were so-called, heavy and light duty engines. This does not relate to robustness, but instead to power and torque. The light duty engine has smaller valves and EGR for emmissions in some US States. Avoid the light duty engines.

They don't have a vacuum pump, so you will need to find an alternator with a vacuum pump.

I was set to buy a 6.5 NA engine for my bushie (hence name Bush65) but saw the light just in time and bought a 3.9 litre Isuzu (4BD1-T) which is a lot more reliable, with better power and torque than the 6.5 NA chevy.

[Astro_Al]

They may be heavy in comparison to an alloy Rover V8, but they compare favourably with an Isuzu 4 BD1 which was the Australian Deisel option for LWB LandRovers from around 1980 to 1990....

...which is much stronger and more versatile than the NV4500

Bill.

Bill, just because heavier engines have been used, doesn't mean this one is light! I still think it's pointless weight. But I respect your opinion.

If you use the correct lubricant, the NV is plenty strong especially in such a light vehicle. How exactly is a T98 more versatile - as I understand it, you've got syncro on 'some' gears, no 5th gear or overdrive ratio and only one PTO provision - not exactly a killer list of features compared to the NV...?

Al.

[bill van snorkle]

Bill, just because heavier engines have been used, doesn't mean this one is light! I still think it's pointless weight. But I respect your opinion.

If you use the correct lubricant, the NV is plenty strong especially in such a light vehicle. How exactly is a T98 more versatile - as I understand it, you've got syncro on 'some' gears, no 5th gear or overdrive ratio and only one PTO provision - not exactly a killer list of features compared to the NV...?

Al.

What I meant Al was that the combination of 4 spd wide ratio T98 and 27% 2 speed Ranger torque splitter was more versatile in that it gives 8 effective speeds with a lower ratio 1st of 6.55:1 (Ford Thames version).

Versatile in that the mainshaft spline is almost identical to series landy. Cheap as chips here in OZ.

Can run them on any old oil. Don't blow their stack when synchros get a bit long in the tooth.

John , aka Bush65 I know a couple of blokes who are going to be extremely pee'd off when I show them your post listing all the faults with their expensive GM engines. Thanks for sharing. I am glad now that I didn't buy one and instead opted for tried and true, and cheap!

Bill.

[BogMonster]

John , aka Bush65 I know a couple of blokes who are going to be extremely pee'd off when I show them your post listing all the faults with their expensive GM engines. Thanks for sharing. I am glad now that I didn't buy one and instead opted for tried and true, and cheap!

Bill.

Blimey having read what Bush65 wrote I thought to myself "and people moan about LR being unreliable"!!!

[headdamage]

This tread is a little old but I thought I'd add that I've got a 6.2 diesel with 500 000+ Km's on it and it still runs though it could use a new timing chain and injectors but even so it still goes better than my fresh 2.5na diesel Also I've helped a friend install a 6.5na into a 110 using an NV4500 adapted to the LT230 and it worked out really well.

[Mo Murphy]

Doesn't everything go better than a 2.5 Na lump ? Well, apart from a 2 1\4 Na lump

Mo

[Lewis]

I know this thread is getting on a bit but if you are still thinking about it Jim then I know a guy who has an engine and adapter plate for a ZF 4speed auto for sale, plus he runs two hummers and a 6.2 powered RRC. With a straight through pipe the Hummer really flies

Gatuitous Hummer pics below

Lewis

[Andrew V8 RRC]

Hi, i have also been googeling for hours about these V8 diesels I find evry story/persons view is different to the next, as for the weight issue , Well think of the 300tdi discovery fitted with a bigger inter cooler ,twinbaterys , abs,air con, HD winch bumper ,winch + 30 m of cable, couple of spot lights ,skid plat/steering bar protection, roof rack + alloy box's and roof tent, not to mention the fat bloke driving it ( no slagging intended )

mmmm.... now how much more weight is that than one of these 6.2 diesels would that be???? probably less than the above, funny thing is land rovers will put up with all the above weight ,and still everybody says it doesn't fit it's to heavy !!

another thing the 5.7 over finch V8 also cast steel block and heads and is lighter ( so far found ) by 68 KG compared wit the diesel 6.2 and they don't have torn spring mounts broken boxes ,half shafts etc.

as for reliability the USA army used them still do , a 4.6 rover V8 can put out more power and a Little more torque than a 6.2 yet a mate of mine (he has a 4.6 in a two door classic on an lt77 ) has never broken anything yet and he is no careful driver otherwise he could of kept the 3.5insted ,but he wanted for wheel drifting to be possible

Of coarse the diesel has lot's more torque than a 3.5 and does have a different firing order but all diesels are harder on the gearbox, as the bang from the ignition stroke is a lot harder than the slow burning petrol bang

You will need tougher front springs and harder shocks and a radiator with a decent cooling capacity ,and if your really worried you could beef up the spring mounts just in case.

other than that if you start with a decent engine you should not have any troubles as long as you maintain it properly ,spares should be available for years to come all over the world, it was used by the military after all.

economy wise i read of figures between 20 an 35 mpg in range rovers and discovery's alike (5 speed box and standard 230 transfer box) i have bee looking into this for over two years now.

I have now decided it will be fitted to my two door classic in 2008 , as i intend to galvanize the chassis and body and Any thing else that can be galvanized without distortion this next year.

I am also fed up with the fits an niggles in the V8 constant Little troubles and rising fuel prises even gas is almost half of the price more than it was a year ago and my boot is full with the 120 liter gas tank, and 12 mpg on gas at best is useless.

I intend to do the swap over and make heaps of foto's of the whole project as there is to little information on the net about land rovers with this conversion an how its done all this i intend to put up on a dedicated website for people to view.

Hope this info helps

Cheers, Andrew

[Guest diesel_jim]

Cheers for all that info ^^^^^^^^

I'm going to go Td5 now though.

[steve b]

..my experiences with these reflect the comments Bush65 made....I've taken 2 out to refit 3.9roverV8 due to broken cranks.Water flow is another issue and I've lost count of how many broken starter bolts have had to be replaced. Having said that when they are good and well installed they do pull well and return 25+mpg . I'm sure there are much better engines to retro fit as others have said. Oh and they eat gearboxs/diffs/halfshafts.

Cheers

Steveb

[treebloke]

I know a guy who had one in a Rangie. If he hit the throttle too hard he could break axles on the road. For me that makes it a non-starter - especially when coupled with the enormous weight.

Chris

I have a 6.5 GMC V8 in a soft dash RRC. I have had it four years and the guy before me two and never had any of the problems mentiond in this thread. We did have a problem earlier this year but that was due to a coolant problem and not really down to the engine itself.

With regard to weight the vehicle sits level but it does have air suspension.

It has a sound of its own and you can tell there is something special under the bonnet. It certainly reacts when you put your foot down and of course there is no turbo, it doesnt need one.

It fits much the same as a V8 petrol with room to get around it. Needs a little heat on a cold morning but then fine for the rest of the day.

I have td5's in a 110 and 90 and even with a power upgrade they do not have the low down grunt of the GMC.