Isuzu 4BD1T in a Landie????

[turbo4t]

Sorry guys, I know nothing about Landie's. I had this motor in a Landcruiser once and loved it. Is it a difficult conversion in a defender? I heard they used them in some Counties at one stage? Cheers.

[6.5 rangie]

probably better asking that question on here http://www.aulro.com/" onclick="window.open(this.href);return false;
And answer is yes, gotta fab engine mounts, rest is bolt in.

[Bush65]

Do as 6.5 rangie said if you are interested in this conversion.

When Land Rovers were assembled in Aus, they were fitted with 4BD1 and 4BD1T engines from 1981 to about 89 (not sure of last year), and all Army Land Rovers from the contract coming from project Perentie. The models with the Isuzu began with the Series 3 Stage 1, then the 110 wagon (these were only offered with county trim level), 110 tray top (in 4x4 and 6x6) and 110 HCPU (high capacity pick up). The turbocharged engine (4BD1T) was only fitted to the civilian 6x6 (very hard to find now) and army 6x6, and possibly some later army 4x4.

As fitted to Land Rover the 4BD1 and 4BD1T have several differences to the same engines from Isuzu trucks - it appears Land Rover used some parts from the Isuzu industrial versions as used by the likes of Komatsu in fork lifts, excavators, etc. The flywheel, flywheel housing (puts the starter higher and different bolt pattern for gearbox bell housing), 12 V electrics (truck is 24 V), different oil filter which clears front drive shaft. Also engine mounts are different and the early Isuzu thermostat housing was used in all Land Rovers.

The easiest way to fit a 4BD1 to a Defender would be to buy a 110 wagon and use the engine and gearbox from it. The alternative is to use a 4BD1T from a truck, and tackle the following issues:
- oil filter clearance to drive shaft - can be spaced out or make remote mount
- use Isuzu 5 speed gearbox - strong but need adaptor to LT230 transfer case (Defender t/case will need high range gearing change) - see forum on the link 6.5 rangie gave for possible adaptor kit
- starter interference with left chassis rail - some truck starters have a gear reduction that pushes the motor far out to left - get a different starter or notch chassis (engineering ??)
- use flywheel housing, gearbox and starter from a Land Rover 4BD1 - note a special gearbox bell housing was used in Land Rovers for the 4BD1 - Land Rover used the 4 speed LT95 gearbox until 1985, then the 5 speed LT85 gearbox with LT230 transfer case - the high torque at low speed (impulsive nature from 4 cyl) from the 4BD1 is hard on gearboxes, LT95 is stronger but for good reliability it is best with taper roller bearing conversion in the transfer case (as developed for army), LT85 suffer bearing failure, but can be modified.
- 24 V starter can be used with dual batteries and a series/parallel solenoid
- 24 V alternator can be swapped to 12 V, but needs to have the vacuum pump an rear
- the 4BD1T truck engines have the thermostat housing further left, which can interfere with bonnet bracing
- Defender radiator is different (much smaller) than 110 Isuzu (the 110 Isuzu rad is same as 110 V8 rad except for outlet to lower hose)
- power steering pump on truck 4BD1T is different to clear Land Rover steering box

The N/A (naturally asthmatic) 4BD1 has good torque, but is low on power which can show at higher speed. Turbo charged and with adjustment to screw on the injection pump makes them a very powerful and reliable engine for a Land Rover (still with good economy). They are noisy (diesel rattle) and rough when idling. The idle speed should be increased from stock to smooth them out. When driving noise is quite acceptable to good when reasonable sound proofing is used. The loud diesel rattle is a result of the tuning that is partly responsible for the high torque at low engine rpm these engines are renowned for.

The 4BD1T is a great engine for a Land Rover - great to drive on and off road, great torque and power available, utterly reliable, long lived, and economical. They will handle very high boost pressure and produce high torque and power with no drama and stock components - up to 40 psi and 4000+ rpm with only change to stronger valve springs (and turbo/intercooler of course).