Everything Isuzu but the chassis and body? (4JB1-T thread)

[Senorbarbo]

Hi all,


I’m Javier López. a Spaniard quite obsessed with Landies since I was a child… and that was a long time ago.


For years now, I have been working on the possibility of using the 4JB1-T on a Series. I wanted to offer a complete solution for old Landies. This engine is light, efficient, reliable, and the spare parts are ubiquitous… and it has just enough power to bring a Series close to modern performance on open roads.


However, when it comes to swapping the engine, I found that the original LR gearbox would not withstand the torque, so I researched gearboxes. Then I concluded that the best solution were the gearboxes which already were matching the engine. Then, I discovered that it was neither easy nor cheap to match the MSA gearboxes with the LT76 transfer. I realized that the best option would be to use an Isuzu gearbox + transfer. But then I found out that the Isuzu gearbox output of the transfer would not match the rear differential (they are not aligned). So, I thought that if you are going to purchase the engine, the gearbox, and the transfer, wouldn’t it be best to replace the axles as well? The Isuzu front one has disc brakes, which is something you should do anyway if you swap the engine, and they are more robust than the originals (the original half shafts will not be happy with 30-40 more HP).


Maintenance would be easier too. If you need body parts, go to LR; for everything related to the drivetrain, engine, and gearbox, go to Isuzu.

Of course, I would need to make two custom drive shafts and adapt the axles and steering bar of the front and rear axles to install it with leaf springs... but it is still the most cost-effective solution with the best performance results.
What’s your input?


Note: Despite being Spanish, and hence my love for Landies, I live in Hong Kong, which is where I have the company. This is why I have easy access to Isuzu 4x4 pickups, which have proven ultra reliable.

[grey_ghost]

Hi,

I am definitely no expert but have you researched the Perentie? (Or Australian Stage one diesel).

Perentie came with either 4BD1 or 4BD1T - coupled with a LT95 gearbox (4 speed) and I believe LT85 (5 speed but apparently less robust)

I love the 4BD1 but it is a very rough vehicle - it would probably shake a Series Land Rover to bits.

Lookup Gromit on here - he has a Series 3 with an Isuzu engine in it, I am not sure which one (it’s not a 4BD1).

Good luck - it sounds like an interesting idea.

Cheers,
GG

[cjc_td5]

The J series Isuzu engines are a nice match for a landy, being a lot lighter than the B series engines in the Perentie etc.

A guy in NSW runs a 4JB1 in his series 3 LWB. He runs the entire engine, gearbox and transfer box unit from a Holden TF Rodeo.

I have a 4JH1 in my series 2, with a MYY5T Isuzu box behind it and a remote mounted LT230 transfer case. Mine is a forward control though, and pretty heavily modified. The 4JH1 has been retrofitted with the mechanical 4JB1 pump and timing gears, which is a popular modification here when the electronic pump in the 4JH1 fails.

To my knowledge, everything sold in OZ with a 4JB1 engine would have an independent front end, so there would not be any readily available front axle to swap in? Toyota front axles work pretty well if considering going that way.

Chris

[Senorbarbo]

Hi,

I am definitely no expert but have you researched the Perentie? (Or Australian Stage one diesel).

Perentie came with either 4BD1 or 4BD1T - coupled with a LT95 gearbox (4 speed) and I believe LT85 (5 speed but apparently less robust)

I love the 4BD1 but it is a very rough vehicle - it would probably shake a Series Land Rover to bits.

Lookup Gromit on here - he has a Series 3 with an Isuzu engine in it, I am not sure which one (it’s not a 4BD1).

Good luck - it sounds like an interesting idea.

Cheers,
GG

Thanks for your input. Yes, of course the Perentie is one of my all time favorites. The 4BD1 (T) is a great engine, but I think for a Series is just too much weight and too shaky being each cylinder almost 1 liter. Thanks for pointing to Gromit.

[Senorbarbo]

The J series Isuzu engines are a nice match for a landy, being a lot lighter than the B series engines in the Perentie etc.

A guy in NSW runs a 4JB1 in his series 3 LWB. He runs the entire engine, gearbox and transfer box unit from a Holden TF Rodeo.

I have a 4JH1 in my series 2, with a MYY5T Isuzu box behind it and a remote mounted LT230 transfer case. Mine is a forward control though, and pretty heavily modified. The 4JH1 has been retrofitted with the mechanical 4JB1 pump and timing gears, which is a popular modification here when the electronic pump in the 4JH1 fails.

To my knowledge, everything sold in OZ with a 4JB1 engine would have an independent front end, so there would not be any readily available front axle to swap in? Toyota front axles work pretty well if considering going that way.

Chris

Veeeeery interesting. Believe it or not I do have a FC too, an ex British military 101" ambulance I bought in Hong Kong with less than 12K km on it. Is a project that will take a lot of time, but I love the thing. You can find it in my IG profile.

The point about getting every bit from the Isuzu is that for me is very easy to buy a complete pick up here. Many of them have low mileage and are being retired with less than 100K. It is a brother of the Holden Rodeo and was made in China by many manufacturers (
Foton SUP, Jinbei Jindian SY10, JiangLing Baodian, Winnerway, ZH6500/ZH1021LU2, Xinkai Century, Autorrad Century.... ). It would be interesting to know how the guy you mention in OZ solved the problem of the output and differential not aligned.

Thanks.

[cjc_td5]

Veeeeery interesting. Believe it or not I do have a FC too, an ex British military 101" ambulance I bought in Hong Kong with less than 12K km on it. Is a project that will take a lot of time, but I love the thing. You can find it in my IG profile.

The point about getting every bit from the Isuzu is that for me is very easy to buy a complete pick up here. Many of them have low mileage and are being retired with less than 100K. It is a brother of the Holden Rodeo and was made in China by many manufacturers (
Foton SUP, Jinbei Jindian SY10, JiangLing Baodian, Winnerway, ZH6500/ZH1021LU2, Xinkai Century, Autorrad Century.... ). It would be interesting to know how the guy you mention in OZ solved the problem of the output and differential not aligned.

Thanks.

Nice. Mine is a civilian FC, so 109".
There is a 101" in Perth with a 300tdi in it, and one local with a Cummins and auto box in it.

To my simple engineering mind, does it matter if the flanges are not aligned horizontally? They are already not aligned vertically, and the shaft cannot tell x from y planes, it just spins.... It just introduces more angle in to the joints, being a vector of both x & y planes?
C

[cjc_td5]

Mark's build.

https://youtu.be/hN-DgplvbII'si=lQ1Gm4qerqtNU_Lw

[Senorbarbo]

Nice. Mine is a civilian FC, so 109".
There is a 101" in Perth with a 300tdi in it, and one local with a Cummins and auto box in it.

To my simple engineering mind, does it matter if the flanges are not aligned horizontally? They are already not aligned vertically, and the shaft cannot tell x from y planes, it just spins.... It just introduces more angle in to the joints, being a vector of both x & y planes?
C

There is a lot of literature about it. Dana recommends to keep the angles below 3º per U joint (very conservative), while others say 7º or even higher. But the greater the angle, the risk of vibrations and wear increases, so it is better to keep it as low as possible. Is not the same highway speeds than off road (makes things more critical). Crawling speeds will allow you 25º or more. But at the end, the more straight, the better.

[Senorbarbo]

Mark's build.

https://youtu.be/hN-DgplvbII'si=lQ1Gm4qerqtNU_Lw

WOW! This is a gold mine of information... what a job that family did. I never found it in my searches on YouTube because it never occurred to me to do it with the parameter "holden". THANKS

[cjc_td5]

There is a lot of literature about it. Dana recommends to keep the angles below 3º per U joint (very conservative), while others say 7º or even higher. But the greater the angle, the risk of vibrations and wear increases, so it is better to keep it as low as possible. Is not the same highway speeds than off road (makes things more critical). Crawling speeds will allow you 25º or more. But at the end, the more straight, the better.

I can't imagine you'd be too worried about drive line angles if you run a 101". The drive shaft angles are pretty spunky straight from the factory! LOL