Outer Limits 4x4 Board

Hey guys
posting this on behalf of my friend.
He drives a 3.5 auto ZF RR.
He would like to convert it to a diesel engine of some sort.
By mating a diesel to the ZF box is there any necessary modification required with the box or it should be okay?
Was wondering if anyone dropped in a Toyota 1KZ engine b4?
Would it be okay to just get an adaptor and mate it to the gearbox?

After searching the forum i notice everyone seems to have praises withe the 4BD1T.
Is it a straightforward conversion?
Does anyone make adaptors for it?
Can the auto zf box cope with it?
Any other issues? Would be lovely if someone could brief what are the pitfalls in doing the conversion and whats involved in it.

My friend also ask what's his opinion of the 4JG2 engine?
Well thanks in advance and hope i'm not repeating questions again. But spare us as conversions over here is not common.
Cheers.

The ZF is used behind the 300TDi and the TD5 diesels in discos.

I would expect there would be some differences to the ZF used behind a petrol/gas engine. Because most diesels produce better torque at low revs (compared to petrol/gas engines) the stall speed of the torque convertor is probably lower. The valving is likely to be different, to suit the characteristics of the diesel.

The bellhousing and input shaft is different for the v8 compared to 300TDi and TD5.

The 4BD1 is a strong reliable engine. It was an option in Land Rover 110 when they were built in Australia and widely used by our military. These all had manual gearboxes, but the flywheel housing and bell housing are hard to get now.

The 4BD1 used had some differences to the normal 4BD1 (from an Isuzu truck) - sump (for steeper grades), starter (to clear left chassis rail), flywheel housing, filter housing (to clear front drive shaft), 24V alternator and starter.

A 4BD1 out of a 110 would be easier to fit to a range rover, than one from an Isuzu truck - have one from an Isuzu truck in one of my rangies.

There is someone, who posts on this board, and is intending to use a ZF behind a 4BD1. If you search in the rover forum, this was discussed in the last month or 2. Hopefully he will be able to give you better info.

At the moment, I am changing the v8 in my other rangie to a 300TDi. The 300TDi is in now, but I still have a number of small things to finish. I used an R380 gearbox from a diesel disco (bellhousing and input shaft are shorter on defenders). If I was to do this again, I would use a 2.8 litre powerstroke (similar to 300TDi, but much improved).

Yeah i did briefly looked through the search option and found that topic b4 posting it.

So if we want to retain the ZF gearbox and drop in the diesel engine do u know what work is required on the gearbox? Or can the V8 ZF box still work with a diesel engine without much hassle?

Have anyone tried dropping in a Toyota 1KZ into the Rover b4? Coz these engines are more common in Malaysia.

G'day,

I am sure the 4BD1 would be a great engine drivability wise in front of an auto.

However, I am not so sure a ZF could cope with the torque on a longer term, but would also not be suprised if it could - you would have to suck it and see. I think it is JustinC who is doing this very conversion and hopefully will be able to tell us all about it when it is complete.

As for the 4JG2 engine, a better option is the 4JB1. The 4JG2 is an indirect injection and the 4JB1 is a direct injection, combined with other things the 4JB1 is a superior engine.

Conversion & Precision (in the UK) do a conversion kit to place either the 4JG2 or 4JB1 in front of the ZF auto for a range rover.

There are differences internally from what I understand between a diesel ZF box (as behind of a 300Tdi) to that of a petrol ZF box (as behind the V8), also the Torque Converters are different. I believe the Torque Converters have different stall speeds whilst internally in the ZF boxs the valving is different to make gear changes to suit the torque characteristics of the different engines (diesel and V8 petrol),

Saying that I have a ZF auto box from a V8 petrol with the V8 petrol torque converter behind a 4JB1 diesel engine in a landrover 90 and I absolutely love it. To be really picky it shakes abit at idle which I am told is cured by the change to a diesel Torque Converter. And to be picky to the extend of absolute perfection you can notice that the gear changes are not quite spot on, but also believe this can be tweaked (by a specialist of course) to suit. For the price I paid I would of paid triple for what I have and am perfectly happy with the setup.

As for the conversion itself was easy peasy.

To answer your question;

So if we want to retain the ZF gearbox and drop in the diesel engine do u know what work is required on the gearbox?

Yes, Valve tweaking by a specialist to make gear changes suit the different torque characteristics of the diesel compared to the petrol, and a swap to a diesel torque converter.

Or can the V8 ZF box still work with a diesel engine without much hassle?

Yes it can and is very drivable.

By mating a diesel to the ZF box is there any necessary modification required with the box or it should be okay?

No necessary modifications, but the box can be 'tuned' to suit the engine, and the torque converter can be swapped for reduced shake at idle.

Would it be okay to just get an adaptor and mate it to the gearbox?

Yes.

Is it a straightforward conversion?
Does anyone make adaptors for it?
Can the auto zf box cope with it?

In terms of the 4BD1;

I imagine not.
No.
Not 100% sure.


In terms of the 4JB1/4JG2;

Yes,
Yes,
Yes.


Hope this helps a little

Grubb, can you please provide some stats for the 4jb1 and some info on the conversion - ie cost and source of adaptor, where you are located and so on and what sort of economy you are getting.

thanks,
Nick.

Thanks a big bunch. Well just have to let my friend know about it and will let u know if anything progress.

Grubb, can you please provide some stats for the 4jb1 and some info on the conversion - ie cost and source of adaptor, where you are located and so on and what sort of economy you are getting.

thanks,
Nick.

Sure....

4JBI-T (as used in 88-9? model Jackeroo's and various other)
Cylinders 4
Capacity 2771
DIESEL TURBO
Power 74@3800
Torque 225@2300

For comparison...

110 4BD1
Cylinders 4
Capacity 3856
DIESEL
Power 66@3200
Torque 245@1900

(Taken from Marks Adaptors webpages)

Have both engines (4BD1 in the 110 & 4JB1-T in the 90), the 4JB1 does have noticably slight more power however the 4BD1 does have better low down torque (the stats say this already though), all due to one having a turbo and the other having greater capacity. However, the torque converter with the auto takes care of the low down torque with the 4JB1. Also the 4JB1 is more responsive than the 4BD1 although this is somewhat negated due to the torque converter (if only we could have it all!)

Source of adaptor is Conversion & Precision as posted above in the UK. Cost 380 pounds stirling (~AU$950). (I pulled mine from a wrecked range rover with the conversion)

The conversion is straight forward and all bolt together. The kit comes with bolt on (to engine) mounts which line up to original chassis mounts, however as mine was originally a manaul and the auto is 120mm longer I had to cut the mounts and reweld them forward this amount. This was the most difficult part (so not real hard) for me. If the kit is going into a vehicle that is originally an auto it is all bolt up (although I believe that Range Rovers and Discos have a longer bell houseing on the manaul boxes so bolt straight up also and it is only in the 90/110's that engine mounts have to be moved for auto conversions - I am not sure).

Fuel economy ranges from 10l/100Km to 14l/100Km at an average of 11.5l/100Km with 22,000Km under the wheels - driven pretty hard (for a box) up to 125km/hr on the european motorways with 205/75R16 rubber. Although this is about to change with 255/85R16's now on it.

Currently located in North West England but if all goes to plan will be shipping my 90 to melbourne and be back in Aust. in the next 7 to 12 months.