Thread: Isuzu Newbie questions

Originally Posted by jakeslouw

We never had the Isuzu engine option on the LR in our country, so I'm a little vague about this subject.....

I've read the Parts Number Reference sticky, and I've had a look on Wiki to see what the 4BD1T and 4BG1T engines are all about.

My questions:

- what about the bell-housing conversion, or did the Isuzu just bolt straight on?
- I assume the One Ten and Defender would be better suited, considering a centre diff and permanent 4x4?
(seems that way from some of the thread discussions, but I just need clarity)
- what about the later gearbox? I assume the R380 would be better suited to the torque profile?

Any other insights would be wicked.

The 4BD1's that Land Rover installed in 110's have several differences compared to the 4BD1 from an Isuzu truck:

1. flywheel housing (the housing that bolts to the rear of the block and surrounds the flywheel)
2. bell housing - different bolt pattern to V8, to suit the flywheel housing (LT95 & LT85 gearboxes only)
3. clutch
4. engine sump - not a big deal as the truck sump is suitable
5. engine oil filters and housing - to clear front drive shaft. Truck filters can be spaced out to clear or be remote mounted
6. starter motor

Not sure what you mean with 2nd question and centre diff/permanent 4x4. Land Rover fitted the 4BD1 to series 3, stage 1's (but these were constant 4x4) and 110's.

Don't know what you mean about torque profile. The 4BD1 is hard on gearboxes, but it is not really a torque profile issue, simply weak rover gearboxes for the torsional vibrations. Increasing idle speed helps.

The R380 gearbox will not bolt up to a 4BD1 flywheel housing. Some have done it here but they modify an LT85 bellhousing to suit the R380. But the LT85 bellhousing has to be for an Isuzu (not V8).

You can fit a 4BD1 (4BD1T better) from an Isuzu truck into a 110 or Defender with the Isuzu gearbox. Then you don't have to source the special Land Rover parts and will have a better gearbox and clutch. The downside is conversion to LT230 transfer case.

The stock 4BD1 is tuned to a very conservative level. With a suitable turbo and intercooler plus adjustments to the fuel pump they can give amazing performance for a 3.9 litre diesel. But most people here are satisfied with the performance achieved with a conservative turbo and minor fuel pump adjustment.

Hi jakeslouw,

The 4bd1 is physically much larger than the LR V8 or 19J turbo diesel available at the time and requires a different bellhousing. AFAIK these bell housings were available only in Australia.

People on the forum have Isuzu 4bd1's in Discos and Range rovers as well as Defenders and 110s. Have a search around and read back through the posts in this section and you will see a lot.

The running gear is more or less shared across the LR range for the appropriate year.

The torque impulse will kill most gearboxes (search around for this there are some really good posts by blknight.aus about it) eventually.

Pretty much everything you need to know is on the forum in one way or another, so have a read of the posts - esp in this section - and you will be well ahead.

Edit: Thanks Bush65, you timelined me with a much better post