Isuzu 4BD1 to LT-85 bellhousing info?

[ewmROVER]

Hello all,

Here's a good question for the 4BD1-Rover users... I realize that they are becoming harder to find, but does anyone know of any source for the factory bellhousing that mated the Isuzu 4BD1 diesel to the LT-85 and LT-95 used in some of the Australian military rovers (perentie, 6x6). I'm looking to mate this 4 cyl. diesel to the LT-85 so I can retain a fifth overdrive gear. While I'm at it, does anyone know if this bellhousing would be all that I'd need for the mate or would any other mods have to be done?

Thank you much,
Ethan
ewmakaro@hotmail.com

[Dougal]

There is another option.

It involves an isuzu box which are real strong but real heavy. With an adaptor block they can mate up to the LT230.

This is how my truck works.

I keep hearing about those engines chewing up rover boxes. They have a suspicious amount of torque, more than the numbers suggest.

[ewmROVER]

Thanks, Dougal

Can you tell me more about this Isuzu gearox and the adapter plate that mates it to the LT-230? I love the idea of running the 4BD1 but am having the hardest time finding a transmission to go with it.

Thanks,
Ethan

[Dougal]

Originally Posted by ewmROVER

Thanks, Dougal

Can you tell me more about this Isuzu gearox and the adapter plate that mates it to the LT-230? I love the idea of running the 4BD1 but am having the hardest time finding a transmission to go with it.

Thanks,
Ethan

I've got a top loading Isuzu MSA-5P box, but the ratios in it suck (big gap between 3-4). The cable change MSA-5R box looks like the best option, then use a cable gear lever from your pick of cars.

In my vehicle the back end of the isuzu box has been removed and replaced with a cast block machined to fit. It bolts up to the last part of the original LT85? which bolts onto the LT230.
I think a better bet would be a steel fabrication spanning the gap without the remains of the old rover gearbox. Just get it faced and the holes pitched out by anyone with a CNC mill.

I've described my conversion a bit further in here, try a search and see what you get. If you send me your email I can send some photos too.

[ISUZUROVER]

I agree with dougal, an ISUZU box mated to an LT230 would be the way to do, if you have the skills to do the conversion or can pay someone.

PM Bush65 - he has done something similar but used an ATLAS instead of the LT230 I think (but he has some good pics on how the gear lever is set up on the cable change box).

I have a 4BD1 with LT85, but I am not 100% sure what you need to go that way. Definitely the bellhousing, and also the clutch pressure plate (not sure about the flywheel). There was a place on the sunshine coast in Queensland Australia that used to sell 2nd hand kits with all the bits needed to mate an LT95 to a 4BD1 (I think they got them from wrecked perenties). Don't know if they still sell them or if they have LT85 kits though.

[ewmROVER]

Thanks, guys

Dougal, I'll list my email if you wouldn't mind sending me some pics of your set-up. I know they'd be very helpful in the long run.

I've learned a bit about the 4BD1 but am still clueless about the Isuzu boxes... Is the preferable Isuzu box (MSA-5R) that you mentioned a common option mated to the 4BD1T? If so, which years were they offered in the Isuzu NPR trucks so I can start looking for a donor?

I agree that mating an LT-230 to the Isuzu box would be the most convenient, as I'd imagine that the isuzu boxes are fairly common along with the LT-230. I would have no problem mounting the motor and tranny to the vehicle but would probably need a shop to do any machining for an adapter plate for the transfer case, unless it is a pretty simple straight-forward design.

Thanks again you guys for all the great info and input.

Regards,
Ethan

[red90rover]

I have a friend (in OZ) who converted his V8 110 to an 4BD1 (and later added a T). He has an LT95.

He spend a large amount of time hunting down the gearbox to engine bits through every Rover parts place in the country. They were all custom from Rover at the time and are no longer available as new. If I recall correctly, he said finding a bellhousing was quite easy. It was something else that was really hard to find and for the life of me I can not remember what (I know, really helpful).

I assume your in Oz somewhere? If you are really interested, I could drag up his e-mail addy and PM it to you.

[ewmROVER]

Thanks red90rover.
I'm actually located in the NW US. I'm contemplating the build-up of a series on a 100-109 inch chassis. I currently have in the fleet an 88" but desire a longer wheel base. I have a lot of options right now as its still in the thought process but am absolute about running diesel and am very attracted to the 4BD1T. The rest of the drivetrain is up in the air. The plot thickens as I also have a growing tired 3.9 with a very worn R380 in my 1994 Disco. I am thinking of also converting this to diesel. However, it just seems more of a PITA to do such work to a discovery compared to a series land rover - hence inquiring about "easier" 4BD1/tranny (specifically LR tranny) options as it was once a factory option in a place far far away.

I realize that NONE of this work is a bolt-in type project and am well prepared to do some hacking. I guess my first goal is deciding on the specifics of one of the projects so I know what to start hunting for.

Thanks again

[Mercedesrover]

If you’re dreaming the drive-line up from scratch, why run a Rover tranny? Especially an odd-ball LT-85. At least use an R380.

If it was me and I had the room and wheel-base, I’d be using an NV4500 and an Atlas.

[red90rover]

The only plus to the LT-85 and 4BD1 is they were factory items in Australia. So if you could source the factory items cheap there would be little fab.

My friend in Oz who did this spent around $3000AUD including a low mileage engine.

It probably doesn't make sense in the US, though.

[Dougal]

Originally Posted by ewmROVER

I've learned a bit about the 4BD1 but am still clueless about the Isuzu boxes... Is the preferable Isuzu box (MSA-5R) that you mentioned a common option mated to the 4BD1T? If so, which years were they offered in the Isuzu NPR trucks so I can start looking for a donor?

I don't know the total year range. But the family business owns a 1985 NPR57 which has the cable change MSA-5R mated to a 4BC2 engine (3.3 NA). These engines share many common parts, the box will bolt straight up to either.

I sent you an email with some pics, feel free to post them up. If you need any more specific ones, just ask.

[Bush65]

From others experience, the LT85 is not strong enough for a 4BD1, let alone a 4BD1-T. Usually they have to have a taper roller bearing mod, which maxidrive do here, and even then, some have had problems. The army ones are all LT95 with taper roller bearing mods in the t/case.

I bought a 4BD1-T, but because I could not find a bellhousing for an LT95 at the time, I used a 6 speed MXA-6R Isuzu box (from an NQR I think) and an Atlas t/case. I modified a different Isuzu bellhousing.

At the moment, I have removed the adaptor to the Atlas and will change it to make as short as practical. I used a cable shifter from a small Toyota sedan.

The other hard to source part, that was made for rovers with the 4BD1 is the adaptor for the oil filter elements. In Isuzu trucks, both elements face down on the right hand side. The adaptor faces the elements upward to clear the front driveshaft.

Rover also modified the 4BD1 sump by extending it out to the left.

My 4BD1-T has a gear reduction starter (24 volt electrics) and because of the gear reduction housing the starter's motor sticks out further on the left side and would foul the chassis rail if I used a stock rover gearbox and t/case in the stock location. I would guess it would be possible to adapt a different starter.

The late R380 box is apparently as strong as the LT85 and some use them with the 4BD1 in rovers here in Aus, but I would recommend that you use a stronger box.

The Isuzu 4BD1-T is a great diesel engine for a rover.

[pendy]

What automatics were used behind these engines?

JP

[JSBriggs]

Originally Posted by pendy

What automatics were used behind these engines?

JP

What? Is your left foot busted?


-Jeff

[landrvrnut21]

If you want the Isuzu, my advise is to call David at Thatched Roof Garage, and talk to him. He has done several conversions here in the US using the Isuzu diesel. I talked to him abotu it, and he is able to provdie a bellhousing to mate virtually any rover trans including autos to the Isuzu diesel. I know he did one conversion in a D110; I imagine to the LT77, or posibbly the R380.

Since you are not set on a motor, why not look at the Cummins 4bt to NV4500. From that you can go to the LT230 through a conversion kit available from BCB offroad.

Personally, I have always wondered about using the Mazada diesel and transmission used in the Euro Rangers, and oversea B-series pickups. I think you could almost use the whole drive train, as the transfercase is an assebmly onto the trasnmission, much like a rover. The outputs are even on the same side. Just an idea.

[pendy]

My understanding is they BCB do not offer the NV4500 to LT230 yet. They are trying to get input gears broached from the LT230 to suit the NV4500.

Tell me I am wrong and show me more then a one off example.

JP

Originally Posted by landrvrnut21

If you want the Isuzu, my advise is to call David at Thatched Roof Garage, and talk to him. He has done several conversions here in the US using the Isuzu diesel. I talked to him abotu it, and he is able to provdie a bellhousing to mate virtually any rover trans including autos to the Isuzu diesel. I know he did one conversion in a D110; I imagine to the LT77, or posibbly the R380.

Since you are not set on a motor, why not look at the Cummins 4bt to NV4500. From that you can go to the LT230 through a conversion kit available from BCB offroad.

Personally, I have always wondered about using the Mazada diesel and transmission used in the Euro Rangers, and oversea B-series pickups. I think you could almost use the whole drive train, as the transfercase is an assebmly onto the trasnmission, much like a rover. The outputs are even on the same side. Just an idea.

[Leafsprung]

I dont think David is doing the Isuzu 4bd1 I think he is using a much smaller isuzu motor.

[ISUZUROVER]

Originally Posted by pendy

What automatics were used behind these engines?

JP

I have heard of a couple with ZF conversions - reported to hold up OK.

The later model ISUZU powered buses and campervans had an ISUZU automatic. This should bolt to a 4BD1 but I don't know the number.

[blkdiscoII]

i live about 5 min from thatched roof garage and am there almost every weekend. the best time to contact david is after 10am on fridays, and saturdays. if you want, just pm me what you want to ask him and ill run it by there if you have trouble contacting him. i know for a fact david has done several conversions and recently rolled out a brilliant 110 with an izuzu turbo .

[ewmROVER]

I was once seriously considering the Cummins 4BT with the NV4500 but came to the conclusion that it wouldn't be the best choice due to several reasons ie how deep the motor is and how much vibration they produce. After a lot of research I determined the Isuzu 4BD1T to be a much better choice as they still produce very equivalent numbers compared to the 4BT but are significantly smoother and quieter and have less fitment issues.

Due to the rev range of the 4BD1T (like the majority of similar diesels) I would obviously need an overdrive gear, making the NV4500 a great pick. I've searched pirate for info on mating the NV4500 to the 4BD1 but ran into all kinds of rather contradicting info. Does anyone know cut-and-dry info on mating the two together. My understanding is that the 4BD1 maintains an SAE#3 bolt pattern. At this point I honestly don't know much about the differing bellhousing patterns or the different versions of the NV4500, so does anyone know what I would need to modify/fabricate/acquire in order to mate them together (and what version of the NV4500 - GM/Dodge?)?

Thanks for the info - it is definitely much appreciated.

Regards,
Ethan M

[Dougal]

Originally Posted by ISUZUROVER

I have heard of a couple with ZF conversions - reported to hold up OK.

The later model ISUZU powered buses and campervans had an ISUZU automatic. This should bolt to a 4BD1 but I don't know the number.

The local isuzu dealer has a new truck with an auto. It's a 4F or 4H series engine (OHC) and has a rearward facing starter motor.

[dieselcruiserhead]

Contact Coog or see the Cummins 4BT list, we have been talking about it lately. A guy stateside has the adapter for the Rover and is having copies made..

Here is the thread in the land cruiser section, probably the best thread about 4BD1ts here on PBB
http://www.pirate4x4.com/forum/showthread.php?t=79854

[Bush65]

From a thread on outerlimits bb:

Originally Posted by stage1slave

I know it's old and leaf sprung, but our series3 stage 1 with 4bd1 has a Ford auto ,C4/C???, and the original transfer case.
BRILLIANT Conversion! We were gonna do away with it, until we drove it . Haven't had the said vehicle in low range yet. Gotta love that!

[ewmROVER]

DieselCruiserHead, thanks for the links and info.

Do you have any more info on the guy that is producing the 4BD1/Rover adaptors? At this point, however, I am almost positive of taking the NV4500 route, but who knows- the more options the better.

So just to verify (from the previous 4BD1 post on PBB), the earlier non-turbo 4BD1 had an SAE#3 flywheel housing that can bolt directly onto the 4BD1T version, allowing an NV4500HD (that supposedly has an SAE#3 bellhousing pattern) from a Dodge Cummins diesel to bolt right up.

Or am I missing something? After reading and rereading that post, I'm still confused on whether I would need a "hard-to-find" adapter or flywheel housing to end up with SAE#3 if I found a turbo 4BD1T. Just like it was mentioned on that previous post, is it just as easy as finding a flywheel housing off an earlier non-turbo 4BD1 to bolt up?

Thanks!

[ISUZUROVER]

Originally Posted by ewmROVER

So just to verify (from the previous 4BD1 post on PBB), the earlier non-turbo 4BD1 had an SAE#3 flywheel housing that can bolt directly onto the 4BD1T version, allowing an NV4500HD (that supposedly has an SAE#3 bellhousing pattern) from a Dodge Cummins diesel to bolt right up.

Or am I missing something? After reading and rereading that post, I'm still confused on whether I would need a "hard-to-find" adapter or flywheel housing to end up with SAE#3 if I found a turbo 4BD1T. Just like it was mentioned on that previous post, is it just as easy as finding a flywheel housing off an earlier non-turbo 4BD1 to bolt up?

Thanks!

Have you been told that the 4BD1 and 4BD1T have different engine bellhousings? AFAIK they are both identical. There are very few differences between a 4BD1 and 4BD1T - just that the T has alfin pistons (late 4BD1 have these also), an oil spray to the underneath of the pistons, a nitrided crank, and different oil filter(s) - all the rest is the same.

There was also a 4BD2(T) in some countries - is that ne the different one?