Hey YJers,
After failing for months to get the 4.2l in my best friend's, Jacob, 1990 YJ Wrangler Islander running, we decided to pull the original motor and start the process of swapping in the Kubota V2403 2.4l turbo diesel engine that I originally has in my TJ Wrangler into his YJ Wrangler.
A quick overview of the engine and the build. The Kubota V2403 is a mechanically injected turbo diesel engine that originally had 60hp and 110ft/lbs of torque with the stock turbo that only produced 3 psi of boost. I've updated the fueling, the governor springs and the turbo to a Borg Warner K03 that makes over 20psi of boost which puts the Kubota around 125hp and just over 300ft/lbs of torque at peak boost. This is similar to the original 4.2l hp figures, but a jump in torque figures as well.
As for the driveline it's going to be similar to the build I had in my TJ Wrangler with a few changes. We're going to be using a later model AW4 automatic transmission out of a XJ Cherokee so that we have the better overdrive gear of .75 instead of the .705 that was in the AW4 I originally used. Also instead of going with a low stall torque converter, we're going to be using a heavy duty stock stall torque converter in the AW4.
We are not going to be installing the doubler I had, instead we are just going to be rebuilding the NP231 in the YJ Wrangler with a used SYE kit that I have in my shop to complete the driveline for the YJ Wrangler.
For the intercooler setup this time around we are going to be using an air-to-air intercooler setup compared to the water to air setup I had originally used in my TJ Wrangler build as well.
The thought is between the better overdrive ratio in the automatic transmission, the higher stall on the torque converter and the air-to-air intercooler, all the EGT issues I was struggling with on my TJ Wrangler build won't be a problem with the YJ Wrangler. Also the YJ has a 3.55 axle ratio compared to my TJ's 3.73 which also helps with the gearing as well.
Because I already made the majority of the mounts, we already have the Kubota V2403 installed into the YJ Wrangler, we are just waiting for a 1.25" body mount kit to come before we install the AW4 automatic transmission to the YJ Wrangler. This should be a fast build that we are hoping will only take a few weeks since it was a running setup in my TJ Wrangler previously . . . I hope.
Here is the video if you want to watch it:
Let me know what you think!
Thanks
Grant
After failing for months to get the 4.2l in my best friend's, Jacob, 1990 YJ Wrangler Islander running, we decided to pull the original motor and start the process of swapping in the Kubota V2403 2.4l turbo diesel engine that I originally has in my TJ Wrangler into his YJ Wrangler.
A quick overview of the engine and the build. The Kubota V2403 is a mechanically injected turbo diesel engine that originally had 60hp and 110ft/lbs of torque with the stock turbo that only produced 3 psi of boost. I've updated the fueling, the governor springs and the turbo to a Borg Warner K03 that makes over 20psi of boost which puts the Kubota around 125hp and just over 300ft/lbs of torque at peak boost. This is similar to the original 4.2l hp figures, but a jump in torque figures as well.
As for the driveline it's going to be similar to the build I had in my TJ Wrangler with a few changes. We're going to be using a later model AW4 automatic transmission out of a XJ Cherokee so that we have the better overdrive gear of .75 instead of the .705 that was in the AW4 I originally used. Also instead of going with a low stall torque converter, we're going to be using a heavy duty stock stall torque converter in the AW4.
We are not going to be installing the doubler I had, instead we are just going to be rebuilding the NP231 in the YJ Wrangler with a used SYE kit that I have in my shop to complete the driveline for the YJ Wrangler.
For the intercooler setup this time around we are going to be using an air-to-air intercooler setup compared to the water to air setup I had originally used in my TJ Wrangler build as well.
The thought is between the better overdrive ratio in the automatic transmission, the higher stall on the torque converter and the air-to-air intercooler, all the EGT issues I was struggling with on my TJ Wrangler build won't be a problem with the YJ Wrangler. Also the YJ has a 3.55 axle ratio compared to my TJ's 3.73 which also helps with the gearing as well.
Because I already made the majority of the mounts, we already have the Kubota V2403 installed into the YJ Wrangler, we are just waiting for a 1.25" body mount kit to come before we install the AW4 automatic transmission to the YJ Wrangler. This should be a fast build that we are hoping will only take a few weeks since it was a running setup in my TJ Wrangler previously . . . I hope.
Here is the video if you want to watch it:
Let me know what you think!
Thanks
Grant
