isuzu bighorn engine info wanted Good and Bad

[Ewoke]

I'm looking at repowering my rangie
What sort of things are the isuzu bighorns dieselturbo motors prone too?
ie are they under radiatored.
can you change from auto to manual with a crank change?
computers?
oh and any idea on out put of motors torque?

[Jezza]

The 2.8 (4jb1) or the 3.1 (4jg2) engine?
both are very good and very reliable engines. The 2.8 engines are pretty much bulletproof, the 3.1 engine is similar but they can crack heads if they are allowed to overheat.
Don't need to change anything when doing a manual swap and unless you have the later 3.1 engines with a electronic pump you won't need to worry about ecu's.
As for torque output I don't have a clue but I have never had an issue of not having enough

[Ewoke]

i think it's the 2.8 motor and its going to be hooked up to a 5 speed rangie box etc. do you know diff ratio of the big horns?
i'm thinking the wiegh the same but really have no idea what they are like on fuel.
i do about 1500k a week and want to drive my rangie as my daily driver so want to get it as cheap to run as possible

[mudgripz]

Both the isuzu motors are good and can do huge ks.

The Isuzu 2.8T (4JB1T) found in the 1987-92 bighorns/mus is one of best diesels to come from japan and has no real weaknesses. Runs very cool - usually only 1/4" on guage. Used in Isuzu trucks across the world and if regularly serviced it will last forever - one here in chch has over 1,000,000 ks on it. Can occasionally require a catchcan to ease engine breathing - about $50-100.

2.8 was most economical diesel in major American fuel surveys for many years and will average 30-34mpg depending on use. My first 2.8 did about 34, last one 31.

Motor has reasonable torque standard for a lighter truck - about 225nm and 110-115hp, but is very easy to tune to good power. Advance the fuel pump timing, increase diesel flow, and put a 2.5" bigbore and snorkel on it and it will jump to around 150hp and 335nm - depending on turbo it has. One of mine dynoed at 155hp and would blow away 3.0 surfs etc. Powerful truck and after bigbore fitted it would boost hard from 1500rpm. Did 100,000ks in higher state of tune and still great when I sold it.

Diff ratios for most 1987-92 bighorns are 4.3, though some of the wide body models which came out 31s standard are 4.56.

4JB1T comes with variations in turbo - VI58, VI73, VI74 (mostly on the intercooled models) and VI87. The 58 is a smaller turbo housing and impeller and its best to get motor with a 74. 87 also ok. Housing size and impeller depth affect torque. Turbo size stamped on front of turbo near air intake.

Plenty of parts available - though this may change. 4JB1T one of Isuzu Truck Cos 'unbreakable' series of motors and highly regarded across world. As a result groups out of Dubai are buying bighorn wrecks from round the world, shipping them to Dubai, refurbishing them and selling them into Africa. They are buying all the older bighorns they can get in NZ also - so next few years might change parts situation some.

[gomulletgo]

I'm hoping mudgripz, and anyone else who knows what they are talking about can help me with a few questions regarding the 4JB1T (2.8T)

Are the intercooled versions of the early bighorns the better ones to go for over non-intercooled? which turbos do the intercooled versions come with? just the VI74?

I didn't quite follow which turbos you are saying are the ones to get.

Is it:

VI58 is a smaller turbo housing and impeller and its the "BEST"?

VI74 (mostly on the intercooled models) and VI87 are "OK" to get?

VI73 doesn't get a mention so is that the worst one to get?

can anyone list the common problems that the 2.8T has? I have heard alot of bad things about the 3.1T but apparantly the 2.8T is alot better even though they use the same block

Thanks