SAR JK r2.8 Cummins conversion

[NitroExpress]

Looking great! Any idea of the weight difference between the two setups?

a lot (lol). Shipping weight on the Cummins is 900#, I'd guess that at least 150# is the really cool box. (which jives with what I heard of 768 for the motor). The transmission has to be at least another 40-60 lbs.

The R2.8 engine with associated hardware that comes in the crate, weighs in at little over 500 pounds (without crate and packaging). This and NVH are the reasons I chose the R2.8 over the 4BT (almost 800 pounds).

I hope you and your wife really like this setup, I've sure enjoyed mine. I put one in my '82 Jeep CJ-8 and with a custom 38 gallon fuel tank and I get massive range. I mostly fill it from a transfer tank, so I've not had a chance to calculate fuel milage much, but I think I'm getting in the 27MPG range when I took it on a trip and re-filled at a station.

One item to note on cooling - I wound up going with a large aluminum radiator after hearing of overheating issues when folks used an OEM TJ radiator. I've had zero issue in the Texas summer with cooling. I'm not sure how the JK radiator performs with this engine.

Looking forward to the project completion!

 

[superbuickguy]

first step, install the radiator tubes

downside is I need to weld another bung on the upper tube for the bypass

intercooler plumbing

and waiting again because I don't have a length of 2 1/2" pipe (tomorrow, I hope)

still have the left side tube to do but hopefully tomorrow that will be solved
it's really time to start figuring out where the computer will go

the plan is use the old computer for sensor, speedo, and HVAC control duties. If I can figure out the cruise control that too.

I still have no idea what the airbox is going to look like.. the hole to fill

2" inlet, 3" MAF sensor tube - thankfully someone makes a 2" to 3" 90 degree elbow.... just take a week to get
the box sent by Quickdraw

fun fact, the cap costs $80 to replace
or
just steal it off the old Jeep motor - it fits just fine

 

[superbuickguy]

This is one of the things I'm curious about. The JK isn't new but it isn't old either. So I imagine getting the computer synced will be a challenge... at least for me. lol

I'm not that smart, I'm running it in parallel - more details to come as I do it - but I'm putting the oil sensor, water temp sensor from the stocker on the new motor. The new motor has its own computer and funky display - but the dash will think the V6 is still in there.
Also the speedo goes to the same plug and a big of adapting for the reverse lights.
HVAC runs the a/c pump and that's controlled by the stock computer.
Ignition switch - runs through the stock computer.

IF I get lights - I have HPTuners to turn off sensing whatever it thinks it's missing (as I did with an H3 Hummer Alpha I had)....

the only real question is cruise control because it's drive-by-wire and the new system has its own DBW harness and such. That said, the differences between manufacturers (who are using the same suppliers) is getting less and less....

 

[superbuickguy]

The R2.8 engine with associated hardware that comes in the crate, weighs in at little over 500 pounds (without crate and packaging). This and NVH are the reasons I chose the R2.8 over the 4BT (almost 800 pounds).

I hope you and your wife really like this setup, I've sure enjoyed mine. I put one in my '82 Jeep CJ-8 and with a custom 38 gallon fuel tank and I get massive range. I mostly fill it from a transfer tank, so I've not had a chance to calculate fuel milage much, but I think I'm getting in the 27MPG range when I took it on a trip and re-filled at a station.

One item to note on cooling - I wound up going with a large aluminum radiator after hearing of overheating issues when folks used an OEM TJ radiator. I've had zero issue in the Texas summer with cooling. I'm not sure how the JK radiator performs with this engine.

Looking forward to the project completion!

I don't know either, it's a "I had it so I'll try it" attitude. Arguably V6 makes more heat (as it delivers more hp then a diesel) - but until I get it running, I'm running with "it should work" - for those who don't know, Cummins details what the system needs to meet manufacturer specs.... but that's instructions and reading them would make me break out in hives
my wife is a mechanical engineer - so pretty good at keeping an eye on things when driving her rig.

 

[superbuickguy]

Instead of useless air intakes, Quickdraw should have made a bracket to adapt the throttle pedal....

also substantially bigger - and the hole ain't great

for added thrills the angle isn't the same either....

ah well.

 

[superbuickguy]

one more small advance

I'll weld it then put lips on the pipe tomorrow

 

[superbuickguy]

onto the supply side

now welded and clamped...

and clamped as well

I'm really going to make a solid effort at getting this started tomorrow... wish me luck

 

[superbuickguy]

built a bracket

painted it

then test fitted it, twice, now it's basically in place

need to do a bit of fine tuning but it took heating and bending to put the pedal where the old pedal was

 

[superbuickguy]

my most favoritest thing EVER! ... or not

about the only spot to send the harness through the wall is here...

as I said, not optimal

but drilled through, then spent some quality time trying to thread the connector together.... haven't won yet.... not happy.

this also shows where the computer is going to live....

I might start getting up early, work until 10 then do my office job until late during this little warming thing.

 

[superbuickguy]

thinned wiring harness ready to go in

need a few days of less than 110 degrees in the shop but this is getting close

 

[superbuickguy]

starter is wired. now for all the rest

also wired the speedo and t-case indicator
...next up, computer holder

 

[superbuickguy]

a friend helped with inside and got the gauge pod in place

remember I asked why the other r2.8 conversion Jeep moved the box 90 degrees? I know now

time for a computer mount

and all that is left is paint

 

[superbuickguy]

and a bit of white paint

 

[superbuickguy]

lights are on

 

[superbuickguy]

pay attention to the arrows on the housing, not the instructions in the book...

and with that fixed, first fire
[VIDEO]