Offroad-Express

Hey guys need some info for a mate.

Hes got a bighorn that the engine is well, rooted to put it politely.

Hes looking at a v6 and ive heard that the holden v6 will be the way to go.

preferably looking at something that will be close to bolting in, with new mounts and cross members. hopefully using the auto from the bighorn, or adapting onto the transfercase.

no he doesnt want to put another isuzu engine in there.

Use an engine out of a Holden Monterey. Direct swap so makes it easy.

depending on the year of the bighorn the transfer case will slide onto the back of a holden v6 auto trans. You will have to make an adaptor plate to cover shaft as the transfer case wont slide all the way on (shafts too long).
I havent seen where the mounts are on an isuzu but i had to change motor and gearbox mounts to fit mine.

Its a 1993 bighorn.

Not worried about changing mounts, thats easy.

What year engine am i looking for? preferably carbed unless an injected one will be easy to sus out.

Things that i know will need doing is cross members, driveshaft loop, fuel pump (thinking in line one) hopefully staying away from ecu's unless they are plug an play.

Will the diesel radiator be allright for the v6?

also what about selector placing etc?

could be a trickey wiring job, we only using as bush trucks so get a hole commy and take loom and computer out. The early commy motors dont have the security features the newer ones do. i had a mate try the carby thing but got stuck and gave up and went to a computer, but i think some stockcars runs that setup, tried to reasearch at the time but not much info around.
brought whole car 4 $200 had been rear-ended so took motor/box/wiring/computer out, then sold the shell for 100 buks. cheap as!

pretty sure early 90's to 94 bighorns transfer cases fit - has to be from an auto as the transfer case is seperate.

yep its an auto aswell

So earlier commodore with the injected v6, whole car would be better as then i can grab everything i need including fuel pump.

dont mind doing ecu as long as i dont have to do any splicing etc aka

so the adapter for the xfer case to the back of the trans is just a tube with plates welded on the end to connect it up?

This will all be certified aswell so anything else i should keep in mind?

Hey man, just throwing this into the mix. The original quad cam 3.2 V6 has 190hp which is about as much as the Buick V6 and they seem to go pretty well.

I'm assuming that you mate has the V6 model!

Dirtydog wrote:This will all be certified aswell so anything else i should keep in mind?

unsure on certing
Thats all the transfer bracket is, i used round tubing and my mate uses a piece of square.
Seen them expensive on tm but mine cost nothing (maybe rods and cutn discs), also painted mine cat yellow to try and hide how horie it is. I actually cut a inch off the gearbox shaft to shorten it up a little, but that contributed to my ugly angle on the front drivshaft.

no this is the 3.1 model, reason for holden v6 is because they are bloody cheap to buy and good solid engines.

Ill have a chat to the certifier soon and discuss what is acceptable and what is not.

So far i think this will be an easy swap if i can find a complete car, everything will swap over easy, just have to find places for everything.

only problem i can see so far is pulling the dirty ol diesel out and making everything nice and square (well where it should be).

also looking at possibly putting a hilux front axle in there at the same time so will look into the cost of getting that done.

Go something diffrent put a el falcon motor in it and a ford territory 4x4 trans or gearbox in for some fun?

Or this from Darby's thread about his rodeo

Crash bandicoot wrote:
(snip)
one thing i have learn't today is that the jeep wrangler engine has the same bolt pattern as the isuzu gearbox...GM for ya.
(snip)

Plenty of jeep motors floating around and they are reliable with a good amount of power.
Worth considering anyway.

Price difference is an issue though, can pick up a 3.8 in a car for tless than 500.

So far these are the parts hes looking for:

vn commodore (or complete running engine with ecu and gearbox etc)

toyota leaf sprung front axle, 4.3 ratio (will have to make certain of that but im sure that diesel auto bighorns are 4.3)

So if anyone has any leads cheers for any info

the bighorns have 4.3 diff ratios. but can easily get a 4.55 diff from other model bighorns, then you could put a prado front diff in which from memory is a 4.5 diff ratio

Might have to have a look at that but want to stay away from coils hed rather have leaves i think.

Ill have to see what i can find for him.

Why not use a lexus v8. The lexus v8 auto bell housing will fit onto the isuzu auto then you just make engine mounts.

He doesnt want to run a v8, Just the v6 will do.

But i may keep that in mind for later.

hows the motor swap going?

still looking for a commodore, though we had one but sold the day before we were supposed to pick it up.

ive managed to find a engine crane and etc to use so going well it should be a straight forward job.

Going to take the front diff out for now, and sort out the sump etc when he wants to chuck the hilux gear underneath it.

If I read this thread right, you want to go from diesel auto to Commodore V6? Bear in mind the petrol auto and diesel auto used different transmissions. The petrol used a GM4L30e which is the same guts as a V6 Commodore tranny (not sure if the case is the same). The diesels use an aisin warner AW30-40le (found in Volvo, Lexus, Jeep, Toyota)

Marco Polo wrote:If I read this thread right, you want to go from diesel auto to Commodore V6? Bear in mind the petrol auto and diesel auto used different transmissions. The petrol used a GM4L30e which is the same guts as a V6 Commodore tranny (not sure if the case is the same). The diesels use an aisin warner AW30-40le (found in Volvo, Lexus, Jeep, Toyota)

Whats the diff between a petrol and a diesel auto? Because I have used an petrol auto on a diesel and a diesel auto on a petrol engine and they run alright.

Darby wrote:Whats the diff between a petrol and a diesel auto? Because I have used an petrol auto on a diesel and a diesel auto on a petrol engine and they run alright.

On an Isuzu? Never thought they would be compatible, as petrol one is made by GM, diesel by Aisin Warner. They use different ecu's as well. Completely different trannies.

going to be using commy trans with bighorn transfercase unless the trans mates up easy.

Still on the hunt for a vr commy.

Have you made any progress with your conversion yet? I'm about to start doing the same conversion but into a 98 bighorn that was running a 3.0 DOHC diesel. I have been reading the comments about transmissions/gearboxes with great interest because it would seem the transfer case from my Torque On Demand system is not going to be suitable for mating to the back of the commodore trans...

I do have a good 3.1 manual box and 2.8 manual box, if I could somehow get 1 of them to fit onto the back of the 3.8 I've got, I'd be a very happy man. Although running an auto wouldn't be the end of the world!

BlairH wrote:Have you made any progress with your conversion yet? I'm about to start doing the same conversion but into a 98 bighorn that was running a 3.0 DOHC diesel. I have been reading the comments about transmissions/gearboxes with great interest because it would seem the transfer case from my Torque On Demand system is not going to be suitable for mating to the back of the commodore trans...

I do have a good 3.1 manual box and 2.8 manual box, if I could somehow get 1 of them to fit onto the back of the 3.8 I've got, I'd be a very happy man. Although running an auto wouldn't be the end of the world!

i know the 2.8 manual box can be adapted on to a vn 3.8...cause we got one... we just made a 5/or 6mm adapter plate. skimmed the back of the flywheel so adapter plate fits. spun the diameter down a bit so fits in bellhousing.used vn flywheel and pressure plate with izuzu clutch plate.goes pretty good, have blown up rear diff twice(spat spiders out and then welded it up....) and snapped the rear output shaft of gearbox in two when diff locked up... ours was done on the cheap( read under 500) as only a paddock hack!

also vn v6's are stupid easy to hook up electrically