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Discussion Starter · #1 ·
I have a 98 Land Rover discovery NAS that I would like to convert. I 'am looking at the 4BT or Isuzu. 4bts came mated to GM400 transmissions in some bread trucks and there is an adapter from marks 4wd that will mate up a GM trans to the land rover transfer chase. I have found the adapter from Isuzu swapper that will bolt the Isuzu to a GM trans then I could use the marks 4wd to mate it up to the land rover drive line. Is there a way to bolt the Isuzu to the ZF trans that came in the Rover? I would like to keep it simple as possible. I saw the Defender with the 4BT but have not seen any other Rover pictures with the 4BT in them. I would like to go with the 4BT if possible but I would like to here if anyone has stuff ether engine in a Range Rover or Discovery chassis.
 

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The ZF box in rovers is only rated at 280ft/lbs so would be struggling behind either engine IMO, I prefer to have a decent safety margin. There is a company in the UK http://www.engineconversions.co.uk/landrover.html that sells/makes conversion plates for rovers to 2.8 and 3.1 isuzu engines, I don't know much about these engines so not sure if these are the same bolt patterns as the 3.9l that you are interested in. With a 100" wheelbase you could go for a 4l80e and as you say Marks adapters makes an adapter for the LT230. I have used a TH400 adapter from marks and chopped the end off that bolts to the TH400 and had a flange made up and ali welded to the main body, the spud shaft was the perfect length and allowed me to bolt a Chevy NV4500 to a LT230 which I used behind a 6.5 diesel for a few years. It is now bolted behind a 6bt cummins. A NV4500 behind even a bombed 4bt would take it all in its stride. :)

Gaza
 

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I really like the 4bt but it won't fit under the hood of my astro so I am going to do the Isuzu thing then look for a 4bt to put in something bounce
 

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I have a 98 Land Rover discovery NAS that I would like to convert. I 'am looking at the 4BT or Isuzu. 4bts came mated to GM400 transmissions in some bread trucks and there is an adapter from marks 4wd that will mate up a GM trans to the land rover transfer chase. I have found the adapter from Isuzu swapper that will bolt the Isuzu to a GM trans then I could use the marks 4wd to mate it up to the land rover drive line. Is there a way to bolt the Isuzu to the ZF trans that came in the Rover? I would like to keep it simple as possible. I saw the Defender with the 4BT but have not seen any other Rover pictures with the 4BT in them. I would like to go with the 4BT if possible but I would like to here if anyone has stuff ether engine in a Range Rover or Discovery chassis.
I'm currently going through the evaluation process to convert my '94 Range Rover to TDI (preferably Cummins 4BT). I'm not much for JAP stuff, although the Isuzu 2.8L is very popular abroad. Thanks to info obtained here, I now have enough dimensional info to start measuring. (The local Cummins dealer was of NO help whatsoever!) Based on the little I've had to go on thus far, it looks workable but as mentioned in another post, keeping the horsepower and torque below what the ZF can handle is critical. The Cummins should need very little tweaking to duplicate the output of the Rover V8, keeping everything within a safe margin. I use the Rover for some light duty towing (an open trailer and 1100 lb. race car). I've already made the upgrades to the Rover suspension, so handling the added weight of the Cummins shouldn't pose any additional headaches. I upgraded the air suspension with new bags, Bilsteins and and new control system from Air Ride Technologies to now control each air bag independently. Picking the right ride height is now a piece of cake, regardless of the load. One of my concerns is oil pan clearance when the suspension is dropped to the bump stops. Other small stuff like air filter and battery locations will need to be addressed too, before I can safely say it's going to work as thought. I've yet to see a Range Rover with a Cummins, so it would be nice to be first to do it.
 

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I have the Isuzu 4BD1T in a 1985 Rangerover, same chassis and suspension as the disco.

You need to pack up the front bumpstops at least an inch to prevent sump/axle contact. Once you've done that your engine will still be within about 20mm of the underside of the bonnet. It's a tall engine, probably within millimetres of the cummins as they use the same bore/stroke.

The 4BD1 with added turbo in front of a HP22 has been done. With bad results. Go to www.outerlimits4x4.com and search the rover board, you'll pull it up.

Don't forget to post pics.

The Isuzu 4BD1T has a rev limit of 3600rpm. While you won't want to run it there often, the extra revs really help offroad to grab another gear.
 

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Discussion Starter · #7 ·
Hey newswede it is great to here about your range rover. I was begining to think I was the only rover nut on this side of the pound that wants to shoehorn a non rover diesel in their rig. The Isuzu is a great engine. I drove an NPR truck along time ago in a old job, the truck always ran smooth and had plenty of power. I also drove some dodge trucks and like the cummins engine also. What I go with will come down to price and availability of donor truck. Hey dougal thanks for all the answers to my posts. Do you have any pictures of your rangie?
 

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Hey newswede it is great to here about your range rover. I was begining to think I was the only rover nut on this side of the pound that wants to shoehorn a non rover diesel in their rig. The Isuzu is a great engine. I drove an NPR truck along time ago in a old job, the truck always ran smooth and had plenty of power. I also drove some dodge trucks and like the cummins engine also. What I go with will come down to price and availability of donor truck. Hey dougal thanks for all the answers to my posts. Do you have any pictures of your rangie?
Yes, I've made several inquiries with most of the usual Land Rover specialists; some have done 200 and 300 TDi conversions as well as the Ford transport 2.8, but I've yet to find anyone stateside currently offering anything that has moderate power for my needs. Most have gotten away from diesel conversions for whatever reason)s). I was considering getting rid of the Range Rover in favor of a Dodge w/ a 6/BT but it's way more than I need; and once you have a truck, your friends (without trucks) start planning your weekends from now until retirement. The Range Rover gets me around in quite reasonable comfort in any weather we have here, and does an adequate job towing, which is why I really want to keep it.

I'm fortunate to have an excellent machinist and a very talented fabricator as two close friends who help me with my various race car projects, so if I can figure a way to slide a 4BT in, we can make the rest of it all work. From Dougal's earlier post, it sounds encouraging, but I'll need to find the right 4BT tasked to the job. If I can keep the torque under 280 ft/lbs and keep the ZF trans, it should be very workable. If it comes down to swapping the trans and transfer case, I think I'll likely not proceed. For now though, it does look promising based on some preliminary investigation. Money-wise, the Rover V8 is still worth a few bucks, so that should help defray some of the expense of the conversion.
 

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My rangie has the Isuzu gearbox to go with the engine. I can supply cad models (solidworks) for the adaptors that were made to mate the back of these gearboxes to the rover LT230 transfer case.

It's simply a few adaptor blocks and a splined adaptor shaft. If you have a tame machinist then you'll be set.

Of course the Isuzu truck gearboxes are slow shifters, not a problem unless you're doing 1/4 mile sprints.
 

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Discussion Starter · #10 ·
the adaptor from marks 4x4 mates up the chevy 400 auto to the rover case so you do not have to change out the LT230. all you have to do is fab up the motor mounts. I 'am worried about the fit under the hood. I looked at the drawings for the 4bt on the yahoo forum and it was hard to read the measurments for how tall and long the motor is.
 

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the adaptor from marks 4x4 mates up the chevy 400 auto to the rover case so you do not have to change out the LT230. all you have to do is fab up the motor mounts. I 'am worried about the fit under the hood. I looked at the drawings for the 4bt on the yahoo forum and it was hard to read the measurments for how tall and long the motor is.

Perhaps a picture will help.

Are there any length issues fitting the T400 box between say a 4BD1T and an LT230?
 

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Discussion Starter · #12 ·
I do not know about the engine and trans lenght. I was going to make new drive shafts any way to handle the diesel's torque. So I will ajust for moving the setup back or forth. Thanks for the picture it did help with seeing the end product.
 

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You can't shift the transfer box back far before you need to do sheetmetal work. The tunnel finishes to a flat floor in the back seat footwell.
 

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Discussion Starter · #14 ·
I crawled under the truck the other day and it looks like there is about 2 to 3 inches of tunnel left before the flat back. There looks like alot of trail and error with this project, but the rover is not my daily driver anymore so I will not have to rush the job.
 

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Perhaps a picture will help.

Are there any length issues fitting the T400 box between say a 4BD1T and an LT230?
The picture was very helpful. With the brake master cylinder on the right side, it looks like it fits well. Would it fit with a LHD vehicle and the boost on the left side? I also am going to need to deal with the the Wabco pump and all the other fiddly bits, so I'll need to take all this into consideration before making the final decision [gulp.... grasp checkbook firmly and take a deep breath].
 
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