Thread: Early 4BD1-T

overhaul kits?

if you stocked em you would go broke, nobody buys em

in Victoria, the best/cheapest place to buy parts (incl. many/most Landrover specific accessories) is often the local Isuzu trucks spare parts dealer - e.g. oil pressure sensor - $15 from isuzu, $86 from 3rd party LR specialist, $130+ from LR themselves... 12 volt ancilaries maybe a different story though!

I have always dealt with SMS diesel in Melb for spare parts, they quite often have both genuine and aftermarket rebuild kits for these engines. Last one was about $1200 from memory, pretty sure it covered everything except the rear main seal. Never had any problems, well not any caused by the rebuild kits anyway.

I have an '87 IHI turbo'd 4BD1T and its a LOT quieter than the '81 N/A in my stage 1, although the 110 has a little more sound deadening the motor itself is definitely quieter and smoother.

Does the engine you're looking at have the extra cover over the rocker cover? or is it earlier than that?

The other changes (if its a truck engine) are starter motor issues, oil filter mods and maybe the thermostat housing, but the gurus here will know if there is any internal differences to the engine itself.

Will be interested to know about this too.

Lyle.

Don't know too much ATM, I've asked the fella a few questions (he and it are in Sydney, I'm 350km away) and apparently it came out of an Australian registered vehicle so isn't an import, at least this time around, but I'm awaiting pics via email.
If it looks promising I'll try and get a mate to have a look at it and see exactly what is what, if it has the Australian ADR 30 label on the engine, etc.

I wouldn't mind getting one to rebuild (although I said I'm sick of working on cars in another thread) as I'd know exactly what was what internally then, I'd balance rods and pistons, get the crank and f/wheel balanced, etc.

There have been some changes over the years, but it is difficult to find definitive info of what exactly and when.

For example my manual clearly depicts the IHI turbo. I have noticed the numbers on the fuel injection pump are different between what is given in the manual and what is on my 1989 4BD1T.

I believe the valve timing changed after 1988 models, along with injection timing.

I believe injectors also changed, but don't know the change over year.

The turbo changed from IHI to Garrett free float and very late models might have Garrett wastegate turbos. The free float turbo has a large A/R and does not produce high boost pressure - you need to give the engine more fuel to get the turbo to spin faster. The manifold changed for the Garrett turbo and it is better suited for mounting an upgrade turbo (may need a T3 to T2 adaptor).

My clutch is larger than earlier models 305mm vs 275mm. Because I used a different gearbox I had to find a different clutch plate with larger spline in the hub and from memory I found 3 different clutches over the years. I can't recall the year when they changed to the 305mm clutch, but the clutch for the larger gearbox input shaft was 1991 on.

Earlier models had a shorter hump on the acoustic cover (over rocker cover).

To me the 89 and later appear quieter, smoother and perform a little better. From the pics below you can see:
1989 year, 121 HP at 3000 rpm, using 70.0 mm^3/stroke for rated power
1985 year, 116 HP at 3000 rpm, using 70.4 mm^3/stroke for rated power

I have an early one. But mine is JDM and I think higher rated than the US or AUS versions whcih most of the figures are from. AFAIK mine was a 105kw engine. It has 10mm pump elements, slightly larger than the later engines and has the boost compensator.

The IHI turbo is a good one, but parts for them are impossible to find. I have one here with an eroded compressor wheel which I can't replace.
Fitting the later model manifold requires tweaking the dipstick to a new location. Not a show stopper, just annoying.

The clutch and clutch plate are smaller (John's sizes are accurate) and appear identical to the ones swapped over as landrover parts. I'm currently running a 4BE1 clutch plate. It hasn't slipped yet.

The longer hump on the rocker cover appears to be to make room for the longer US EPA sticker. The earlier ones when sold in the US had a plate spot welded to the cover to provide sticker room. Under the top cover the breather setups appear identical.

I have some injector tips here from my engine. Just ask if you want any info from them.

For rebuild kits, I've found the critical parts are the crank seals, gaskets and rings. Aftermarket liners appear identical but don't have the option to grade by diameter, this can make a big difference in idle noise.
I bought an aftermarket gasket set once, about half the gaskets fit and the composite head gasket was absolute crap. Never again.
I run aftermarket pistons, I had a liner kit and couldn't buy the pistons seperately last rebuild (5 years ago), no problems yet. Visibly identical to the Isuzu pistons apart from the logo. Possibly the same factory makes them.

The white smoke is usually Injector pump timing out. The engine is probably fine

Regarding overhaul, it will be hard to get better parts and gasket kits than genuine Isuzu.

The engine has dry liners with chromed bores. Turbo pistons are alfin - don't get non alfin.

The turbo crankshaft is tufftrided for increased fatigue strength. It is very hard and wears well, but can't be re-ground because thickness of tufftriding is not uniform.

The rear crank seal leaks. There are a couple of upgrades for this seal, both include a sleeve that fits over the crank. One is Isuzu part, other is SKF/CR seal, which is the one used for Army 4BD1's now.

They are very robust, designed for a long service life and made to be rebuilt. In many ways they are more robust than the very similar Cummins 4BT, e.g. larger head bolts and larger bolts in main bearing caps.

The stock MLS head gasket and bolts are good enough for 40+ psi boost pressure. People have run them at 5000 rpm with over 40 psi boost reliably with stock bottom end, head bolts, etc. - need pump adjustment, turbo upgrade and Crow/Crower Chev/Holden V8 valve springs.

If the turbo is shot good luck finding spares for it,you may need to fit the later manifold and turbo.
A genuine rebuild kit will cost around the $1200.00 mark which includes the rear main seal,pistons,liners,bearings(mains and big ends),most gaskets and seals,rings,piston pins.
You don't get cam bearings or welsh plugs.
The lower oil filter spacer is still available from rover parts suppliers but you'll need to get the upper one made.
The right hand steel engine mount is still available from isuzu or you could try the wreckers,the left mount is easily modified to suit.
A bit of notching to the chassis for the starter motor isn't too hard to do.

Cheers Eric