4jb1t or 4jg2t into jeep cherokee

[chriskasian]

Hi everyone,

I'm from Canada and looking to purchase either a 4jg2t or 4jb1t to put in a 1993 jeep cherokee. The cherokee weighs about 3000 lbs and the automatic transmission offered is the AW4 which I believe is the same automatic offered with the bighorn 3.1l (aw 30-40). At first I was considering this swap combo since the 4jg2 can be found with transmission and and transfercase for around $2500.

Now after reading more and more I am considering the 4jb1t. Reasons for this are: Direct injection so in cold weather where I live it should start nice, from what I have read better fuel economy, and some come with a gear driven setup as opposed to belts.

The negatives to this motor as far as I can tell are: its older, parts can be harder to find here. And for swapping into a vehicle here in Canada, the motor needs to be newer than the vehicle for it to be considered legal.

A primary motivator for this build is for a fun project and for fuel economy so I can drive back and forth between provinces.

So, from what I have read the 2.8l with a manual will give me the best mileage, with the 3.1l manual not far behind. ( on a side not... I probably will run about a 31" tire and regear the jeep if necessary).

I hear the autos seem to suck the power and economy from the motors, but in many ways I think I would prefer an auto.

So basically I'm looking for opinions on which combo to choose and why for some insight to things I have not thought of.

I really appreciate any responses Thank you.

[stardog]

I have seen it done but the jeep had a 3.9 isuzu none turbo engine a while back but the guy sold it. If i was going to do it which i have been thinking about for a while i would be dropping the intercooled 3.1 manual in the cherokee.
The cherokee what fun it would bee then they have the 4 litre petrol motors in them over here and are thirsty on fuel but are great out 4x4 in the bush when set up right.

[chriskasian]

Thank you for your reply. The fuel consumption of many gas motors out here is rediculous, can hardly afford to run them. I would like to be able to get about 8 or 9L/100 km. Is this a reasonable goal for a vehicle of this weight and a 3.1l manual?

[stardog]

Just came across this about the converting to a diesel most people are using cummings engines but this 1 is for a isuzu.
http://www.canev.com/Jeep.html
I think this might help you out a bit.

[chriskasian]

Yes I have seen this page before. Thank you for posting it. It sounds like he has gotten great results and I hope I can produce similar ones. The Cherokee his engine went in should be about 700lbs heavier than the model I am planning on installing the motor in. So maybe if I'm lucky I can get a bit better economy than him. I wonder how easy it is to bolt the 4jg2 to the AX 15 transmission. Looks like all he needed was a simple aluminium spacer (I'm assuming) with a bellhousing. One thing I am uncertain on is what flywheel/pressure plate/clutch setup I should be using any insight into that? (I have never worked on a vehicle with a manual transmission so a lot of this is fairly new to me)

Thanks again
Chris

[stardog]

I think the easy way would get the isuzu engine and gearbox together and drop them into it. But the front drive shaft from the transfer case sits on right hand side under the drivers side or over your way the passenger side if as if i remember right your cars are left hand drives.
You could talk to the guy on the site and ask him about the bell housing adapter and clutch set up that he done.

[geeves]

I would like to be able to get about 8 or 9L/100 km

of the 2 engines the 4jb1 might even do better than 8 in a cherokee the 4jg2 will be around 9 or slightly over. In my bighorn which is pushing 4000 pounds and a more shed like in shape will do 8.3 l/100km at an average speed of 100kph but that is on a manual trans. Both engines are available with the auto trans and looking at my book it should have a separate bellhousing. If this is the case then taking the isuzu bellhousing and bolting it to your auto will save a lot of headaches.
The 4jb1 was sold in the utes in some markets up to about 98 so a later motor should be available but how to verify the year of the engine I dont know. Licensed copies of this engine are still made in China and Brazil.
Another option is the 4ja1 engine This is only 2.5l but much the same horsepower and similar economy to the 4jb1 It was also sold in USA in some vehicles. It was a new engine in the late 90s so it must meet the rules

[chriskasian]

I think the easy way would get the isuzu engine and gearbox together and drop them into it. But the front drive shaft from the transfer case sits on right hand side under the drivers side or over your way the passenger side if as if i remember right your cars are left hand drives.
You could talk to the guy on the site and ask him about the bell housing adapter and clutch set up that he done.

Yes dropping in this combo would be very easy and if the output shaft (21 or 23 spline in north america) and bolt pattern on the back of the transmission are the same as the version sold here (that came in the cherokee) I should be able to swap the transfercase for the correct side differential.

I would like to be able to get about 8 or 9L/100 km

of the 2 engines the 4jb1 might even do better than 8 in a cherokee the 4jg2 will be around 9 or slightly over. In my bighorn which is pushing 4000 pounds and a more shed like in shape will do 8.3 l/100km at an average speed of 100kph but that is on a manual trans. Both engines are available with the auto trans and looking at my book it should have a separate bellhousing. If this is the case then taking the isuzu bellhousing and bolting it to your auto will save a lot of headaches.
The 4jb1 was sold in the utes in some markets up to about 98 so a later motor should be available but how to verify the year of the engine I dont know. Licensed copies of this engine are still made in China and Brazil.
Another option is the 4ja1 engine This is only 2.5l but much the same horsepower and similar economy to the 4jb1 It was also sold in USA in some vehicles. It was a new engine in the late 90s so it must meet the rules

One of the more important aspects of this swap to me is the fuel economy. I am not in much of a rush to complete this project. I must say that 8l/100km would be fantastic.

The manual transmissions offered with the 2.8l and 3.1l diesels are made by aisin (MUA5) which shares the same bolt pattern as the AX15 found in jeep cherokees. If I could find a 2.8l diesel with a manual attached I may be able to use the bellhousing and flywheel from that transmission to adapt the AX15 transmission.

Out of curiosity, do you know/heard of anyone using a licensed copy of one of these engines?

[slightlydodgy]

Just to throw a spanner in your works the bell housing on the MUA5 isn't removable or interchangable

[chriskasian]

Just to throw a spanner in your works the bell housing on the MUA5 isn't removable or interchangable

Haha that's going to slow this down abit.

[geeves]

the bellhousing on the auto apears to be though

[stardog]

Read this thread.
http://www.4btswaps.com/forum/showthrea ... lease-help
It seems quiet common in phillipines using 4jb1t and AX15 transmission together to repower cherokees over there.

[chriskasian]

the bellhousing on the auto apears to be though

Yes I believe that is correct. I wonder if something like that could be modified to work....

Read this thread.
http://www.4btswaps.com/forum/showthrea ... lease-help
It seems quiet common in phillipines using 4jb1t and AX15 transmission together to repower cherokees over there.

That's interesting... Maybe I'll resurect that thread see if there is more info to be found

[chriskasian]

With all that extra work gotta wonder if it's worth an extra 2l/100km possibly a difference of about $20 per tank for the same distance....

[geeves]

2l/100km ?
The petrol jeeps over here average 17mpg or about 16l/100km
Even with Americam gas prices thats lots more than 20 bucks a tank

[chriskasian]

2l/100km ?
The petrol jeeps over here average 17mpg or about 16l/100km
Even with Americam gas prices thats lots more than 20 bucks a tank

I did not clarify. I mean between the 4jb1t and 4jg2t manual/auto gains lol. I curently drive a dodge dakota and get 20l/100km. Hurts the wallet a lot.

[geeves]

I have a early bighorn/trooper with a 4jb1 and manual and a wizard/rodeo with 4jg2 and auto. The wizard is 7 years younger and far nicer to drive but the difference means getting 600km to 700km to a tank instead of 700 to 900km in the Bighorn. The auto and extra weight pretty much eats all the power difference although the 4jb1 is running extra boost. The bighorn is noisy due to no carpets and has all the wrinkles you would expect from being used offroad for 16 years. Its no longer a pretty car

[chriskasian]

I have a early bighorn/trooper with a 4jb1 and manual and a wizard/rodeo with 4jg2 and auto. The wizard is 7 years younger and far nicer to drive but the difference means getting 600km to 700km to a tank instead of 700 to 900km in the Bighorn. The auto and extra weight pretty much eats all the power difference although the 4jb1 is running extra boost. The bighorn is noisy due to no carpets and has all the wrinkles you would expect from being used offroad for 16 years. Its no longer a pretty car

Well that settles it. It's going to be a 4jb1t and 5 speed manual. Since its going to be a engine older than the vehicle maybe I'll spring for a bit of a newer Cherokee like a 98. Reasonably newer

[chriskasian]

Well I think the easiest way to proceed with bolting the AX15 to either the 4jb1t or 4jg2t would be to either dill out holes on the motor plate if it is large enough to accommodate the ax15 bellhousing or to fab a new plate up.

Other than ensuring everything is perfectly lined up, and to correct depths, I don't believe this will be to difficult of a task, just time consuming.

[chriskasian]

So out of curiosity, has anyone heard anything about these chinesse copies of the 4jb1t? I have been emailing a company and they want about 2700 YAUN per engine, so around $500 Canadian. Engine crate is only 0.52m^3 so shouldnt be to much for shipping lol. Has anyone ever heard of one of these things running? From the amount of money these companies make, these copies must be used in china and other places......

http://kaijiauto.en.alibaba.com/product/295687575-200221770/4JB1T_diesel_engine.html?edm_src=sys&edm_type=fdbk&edm_grp=0&edm_cta=read_msg&edm_time=realtime&edm_ver=e