Thread: Discovery I to Isuzu 4BD1T

Originally Posted by discodiesel

Thanks you all for the quick reply. First the starter, my starter is a 12V that is held in place by 3ea. bolts. Obiously I dont have the LR flywheel cover which brings me to the next question.
Would it fit using the Isuzu flywheel cover and replacing the start unit with one more compact?

My Disco has the steeringwheel on the L/H side. Does any one knows if the engine will fit with the steeringwheel on the left side?

Another issue is the auto transmission most people agree that it wont last long. Whats your take on this? Have someone try to use the auto transmission of the Isuzu truck?

What about the L/R flywheel cover they are easy to come by in Australia? If so what is the market price?

Onece again thank you for the replies. The engine has been sitting for a year now and I am ready to get it install.
Any comment, pictures & ideas wheel be greatly appreciated.

YR

The 4BD1's used in Isuzu/Chev trucks the USA had the same 12V, 3 bolt, reduction gear, starter motor as Land Rover used here. But the Land Rover flywheel housing moved the starter higher.

4BD1's used in Isuzu trucks in Australia had 24V, 2 bolt, reduction gear, starter motors.

The reduction gearbox on these starters cause the width to increase substantially. That is why Dougal has used a direct drive starter (which is what I will do this time).

AFAIK, all Isuzu's in Australia, which had the 4BD1's only had manual gearboxes.

I'm not aware of anyone transplanting an auto from an Isuzu truck into a Land Rover.

The autos were used in Isuzu trucks in the USA. AFAIK they were Allison units, but the model used did not have overdrive or lock-up. By fitting another US auto, you can have o/d and lock-up. (the ZF used in Disco's is not up to the duty).

Originally Posted by Dougal

Nope. No body lift here and I don't plan to fit one.
Just packed the front bumpstops by 20mm.

Just like this last one I bought, someone had done the conversion without a BL, motor sits to low and I think its crude, but only my opinion

Originally Posted by rovercare

Just like this last one I bought, someone had done the conversion without a BL, motor sits to low and I think its crude, but only my opinion

Crude? How so?

Raising the COG of my truck by 2 inches without increasing ground clearance or suspension travel has never struck me as a good thing to do.

Originally Posted by Dougal

Crude? How so?

Raising the COG of my truck by 2 inches without increasing ground clearance or suspension travel has never struck me as a good thing to do.

Packing out your bumpstops, keep in mind, mine is used for the bush

How haven't you reduced suspension travel? drop the shock towers to match?

Originally Posted by rovercare

Packing out your bumpstops, keep in mind, mine is used for the bush

How haven't you reduced suspension travel? drop the shock towers to match?

I have reduced suspension travel by that 20mm or so extra in the longer bumpstops. It's been airborne a few times and seems to cope.

I have planned to put longer shocks in (80 series landcruiser or similar) but still haven't got around to it.
I considered chopping the shock towers, but that would mean those longer shocks above may no longer fit.
It's all on the list somewhere behind "fit intercooler" and somewhere before "cut and polish".

Still outflexes all the japanese stuff.

Originally Posted by Bush65

The 4BD1's used in Isuzu/Chev trucks the USA had the same 12V, 3 bolt, reduction gear, starter motor as Land Rover used here. But the Land Rover flywheel housing moved the starter higher.

4BD1's used in Isuzu trucks in Australia had 24V, 2 bolt, reduction gear, starter motors.

The reduction gearbox on these starters cause the width to increase substantially. That is why Dougal has used a direct drive starter (which is what I will do this time).

AFAIK, all Isuzu's in Australia, which had the 4BD1's only had manual gearboxes.

I'm not aware of anyone transplanting an auto from an Isuzu truck into a Land Rover.

The autos were used in Isuzu trucks in the USA. AFAIK they were Allison units, but the model used did not have overdrive or lock-up. By fitting another US auto, you can have o/d and lock-up. (the ZF used in Disco's is not up to the duty).

Apparently most people installed this engine on a LR and increase the HP and torque and the ZF is not up to the task. Now I am trying to found out is the transmission will hold fine running the engine without increasing the HP/Torque.

Originally Posted by discodiesel

Apparently most people installed this engine on a LR and increase the HP and torque and the ZF is not up to the task. Now I am trying to found out is the transmission will hold fine running the engine without increasing the HP/Torque.

The problem is not because the owner increased the hp or torque.

The problem is that it is a long stroke 4 cylinder diesel that makes a lot of torque in stock condition at low engine rpm's.

At low speeds the power pulses are spaced further apart than a 6 or 8cyl engine. The diesel fuel burns slower so when the long stroke crank is at nearly 80 degrees after top dead centre a lot of pressure applied to produce the high torque.

The torque is not applied smoothly at low speeds, which sets up strong torsional vibrations that destroy the transmission (manual and auto).

There is a vibration damper on the front of the crankshaft, but it does not do a good enough job to protect transmissions that are not of rugged construction. The very similar Cummins engine has a huge vibration damper and a much heavier flywheel by comparison.

The ZF transmission has a high enough power rating, but that is for smooth operation at higher speeds, not for the characteristics of a 4BD1.

Don't waste your time and money trying to get the rover ZF transmission to live happily behind a 4BD1. If you want an auto, get a rugged US transmission.

Originally Posted by Bush65

The problem is not because the owner increased the hp or torque.

The problem is that it is a long stroke 4 cylinder diesel that makes a lot of torque in stock condition at low engine rpm's.

At low speeds the power pulses are spaced further apart than a 6 or 8cyl engine. The diesel fuel burns slower so when the long stroke crank is at nearly 80 degrees after top dead centre a lot of pressure applied to produce the high torque.

The torque is not applied smoothly at low speeds, which sets up strong torsional vibrations that destroy the transmission (manual and auto).

There is a vibration damper on the front of the crankshaft, but it does not do a good enough job to protect transmissions that are not of rugged construction. The very similar Cummins engine has a huge vibration damper and a much heavier flywheel by comparison.

The ZF transmission has a high enough power rating, but that is for smooth operation at higher speeds, not for the characteristics of a 4BD1.

Don't waste your time and money trying to get the rover ZF transmission to live happily behind a 4BD1. If you want an auto, get a rugged US transmission.

Ditto here.
Just to add to what John says, I was fitting ZF's to mine at 10,000km intervals, the second one even had a low stall converter and beefier clutches etc, but still filled the sump pan with metallic bits and clutch material
One of the failed units had stripped the lock up clutch material clean off and was ruuning metal to metal

Go Allison and choose some high gearing/ bigger tyres.

JC