4BD1 or 4BD1-t

[Rangie Thing]

Hi all, just woundering what is the better engine the 4bd1 with aftermarket turbo or the 4bd1-t by price and output. Thanks

[ISUZUROVER]

The 4BD1 and 4BD1T are basically the same motor except for the following items that the T has:

Alfin pistons (late model 4BD1 have these also)
Oil spray to cool piston crowns
Tufftrided/Nitrided crank
Some models have an Aneroid on the Injector pump (Boost compensator)

So of course it is better to have a 4BD1T than a plain 4BD1, but plenty of people have turbocharged a 4BD1 without problems (they are a very strong motor in either form, and both only have 16:1 compression, perfect for turbocharging).

There were lots of different configurations of both engines, with different power outputs.

Most truck 4BD1 engines (and military 110s) were 85bhp, civillian 110s were 99bhp (the difference between the models were just pump mods). By tweaking the fuelling you can get a bit more from either engine.

The 4BD1T usually had about 120-130bhp, but that was running only 5psi boost (without intercooler). Most people I know run about 10psi and an intercooler, which makes a big difference.

Of course if you do an aftermarket conversion you can fit a more modern turbo and get better performance.

So it really comes down to what it costs for either motor - a real 4BD1T is obviously better, but if the oil spray and other bits will make a significant difference to the life of the engine is anyone's guess. I think that in a truck or something else that is heavy and working hard all the time it would make a difference, but in a (comparatively light) land rover with sensible boost and egt values, a turboed 4BD1 should be fine.

[def90]

hey ben,
in the new year i'll be putting a lung on my 4bd1. it is a 1990 stamped motor, these are the models with the extras that you are talking about?

i have a mate that does up imports and brings them into the country, he has a few low klms turbos lying about. he suggested one with a T3 flange (flange same as T25 - fits the isuzu factory manifold - $220ish) and came off a 6 cylinder 2L skyline.

i'll be running approx 10Psi (adjustable) with intercooler - either largish one behind grill in front of radiator, or simple WRX one or similar, smallish, on top of the motor. got running temps off chuck so if stay within that should be ok? should be able to full install for round a grand.

i thought this very cost effective and should deliver good results?

what are your thoughts? i know hard Q but any idea what kind of increase i may be looking at?

[ISUZUROVER]

All sounds good from here Sam. Chuck and others have more experience than me of what works though. But a turbo from a 2L is about the size that seems to work well. Want to pick one up for me too while you are getting yours???

I seem to recall figures of about 135-145Bhp for 10psi and a decent intercooler, but these values are very dependant on a lot of factors. I'm sure you will be happy with it anyway.

What are the EGT values you got from Chuck? Does Kevin have an EGT?

Your motor will definitely have Alfin pistons - don't know about the oil-spray and the crank. In a 90 it won't be working very hard anyway.

If you have a truck engine with stock pump settings, then you will only have 85Bhp at the moment, so 120+ will be a big improvement!!!

[def90]

i'll let my mate know to keep one aside for u, but u'll be a while before your return though wont u?

probably better waiting till nearer your home date and get one then, he usually has spares lying about, or you can come talk to him on your return.

get back to you re egt temps, think he said no higher then 600ish? can't remember, got details at work.

yep from memory kevin did or was going to install.

think i'll have to get my injectors and pump done while doing turbo, presume best way.

[ISUZUROVER]

If your mate often has turbos then you are right, it is probably easier for me to get one when I get back. To make life simpler, you want a turbo that is just oil cooled, not water and oil - not necessary for a diesel.

I think Justin C on here said about 600C max as well.

It depends on what your pump and injectors are like. Not really necessary if they are good, but you do need to increase the pump fuelling.

[Maggot4x4]

If your mate often has turbos then you are right, it is probably easier for me to get one when I get back. To make life simpler, you want a turbo that is just oil cooled, not water and oil - not necessary for a diesel.

I think Justin C on here said about 600C max as well.

It depends on what your pump and injectors are like. Not really necessary if they are good, but you do need to increase the pump fuelling.

What about the turbo of a 4.2L GU pootrol? Or too big?