The Pioneering Spirit's Expedition JKU Build

Comanche Scott

Expedition Leader
Looks good. :beer:
I see you have the 4BT with a P-Pump, so you can disregard my post on injection pump rebuild. Totally different style of injection pumps. Also gives you a lot more room for power. :)
 

jsek29

Observer
Scott,

Yes, we have a P-pump. Bruiser did that to simplify potential repairs in Africa. Truth be told, I'm leaning on their knowledge of the 4BT, i am surprised you can tell that from the posted photo. I'll learn how to service and diagnose problems, but they have been great with selecting the few "options" on this engine. They called earlier this week to discuss which turbo to put on it, they have one in mind that will come into power about 750 rpm earlier, giving low end power, but limiting top speeds. This will be great in Africa, but the. We have the original to reinstall up one return to the states for highway driving. Sorry, I don't remember the designations for the various turbos, but I will get that and post an update.
 

Comanche Scott

Expedition Leader
That would be great to know what turbo they recommend. This is a hotly debated item for the 4BT, with most 4BT fans in the Holeset HX30 camp.

VE is German initials for Vertiler Einspritz (sp?) which basically translates to "distributed injection". So the pump lines run off the back of the pump from a single head. A "P-Pump" is an inline pump with a separate piston for each injection line, and all the lines come off the top. That is why it was so easy to identify from the picture.
It also uses a totally different style of fuel pickup pump, so the point I made of changing fuel pumps is also moot. :)
In any case, from what I've read and seen, Bruiser has a good knowledge of the 4BT, and more importantly how it works in the JK. I think you are in good hands. :beer:

If you are interested in knowing more about the engine www.4btswaps.com forum has a lot of good info.
The Cummins repair manuals used to be online to download for free. Bruiser should be able to supply them for you. If they can't, I *think* I still have copies, but not sure it will include the P-Pump.
Drop me a PM if you need them, and I'll see what I can dig up.
 

jsek29

Observer
More photos of the build from Bruiser.

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Installing a sportcage for additional safety on our trip.

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Sitting tall on our MetalCloak lift.

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They make it look like it came off the assembly line with a Diesel engine.
 

jsek29

Observer
We finally got the call from Bruiser, it was time to book tickets to fly to Florida and pick up our Jeep! The guys at Bruiser offered to pick us up at the airport, which they did, in our Jeep. It was quite a thrill to see our Jeep, in it's new form, come around the corner at the Tampa airport. We could hardly believe it was the same Jeep we had loaded onto a truck the week of Christmas. It sits taller, with a wider, more stable stance. On the ride to the Bruiser shop, we both commented about how it now rides better than stock. Thanks to MetalCloak's Overland Elite lift kit. We also noted how it had more body roll than we wanted, more on that later. The other thing we noticed on that first ride was how the engine noise was relatively quiet. Sure, the stock engine was more quiet, but the Cummins was still tolerable, especially at a cruise.



Once at the shop, we got a quick tour of our Jeep before taking the keys. Dave showed us the work they had done, both inside and underneath. We got to see the custom fabbed air box, how the 4BT fit into the engine bay, where the air chucks are located, and how the drivetrain fit. As it was nearly 7 PM, and we had to get across the bay to our home for the next couple of days, we took our leave with the plan to return the next day to meet the team and go over the build with the head mechanic.

On our way to the shop the next day, we stopped and bought a fire extinguisher, thinking we would mount it on the front seat while at Bruiser. As we pulled into the store, we saw a spot next to another JKU, in stock trim. We parked next to it and took a couple of photos, for comparison's sake. Side by side, the difference seems both drastic and fairly small at the same time. It's only lifted a couple of inches, and the tires are only a few inches bigger, but it all adds up to a majorly different stance.



We got to Bruiser's shop just after lunch and met with Todd, the chief mechanic. We covered some of the outstanding work to finish on the Jeep with him. While the mechanics worked on these items, Todd went over part numbers and fluid recommendations with us, so we know how to maintain our new baby. We got to hang out at the shop and watch the guys finish some of the last items on our Jeep. They put back the stock rear bumper as our next rear bumper isn't ready yet. They installed the radiator fan shut off, so we can cross deep water without tam aging the fan, and ran power for a winch to the rear of the Jeep. We also called Metal Cloak about the body roll and learned that their lift kit is engineered to work with the stock anti sway bars. I let them know that we could not re-install the stock rear anti sway bar, since the GenRight rear fuel tank was in the way. They said to reinstall the stock front anti sway bar and see what happened with the Currie rear Antirock bar. They thought that we might even want to disconnect that as it is much stiffer than the stock unit. Bruiser reinstalled the stock front bar and the difference was incredible. The body roll was now gone, or at least back to stock levels. The Currie unit is nice, but too flexible for use with our lift kit.




Late in the afternoon, Jeff Garland, owner of Bruiser Conversions, and Jeff's Jeep Yard, rolled in the the JK Supercab Pick-Up and talked to us about our build, about his sweet CJ-6 sitting in the shop, and even helped us put on some decals! Everything was finished in a couple of days, so we loaded the spare tire on top, thanks again to MetalCloak for their Overland Fenders which I can stand on, and hit the road. Over the next 2 weeks, we drove nearly 5000 miles from Florida to New Orleans, Houston, San Antonio, Albuquerque, Phoenix, Lax Vegas, Bend, and finally home in the Portland area.



On the way home, we stopped at Pronghorn Overland Gear to get our radiator guard installed. We also discussed some of the things they a re working on for our trip, but more on that when we get those things mounted to the Jeep!



We finally got to take the Jeep offroad in Bend. We met Jen's cousin at China Hat and played in the OHV area. It is amazing what the Jeep can do. In 4 Low, 2nd gear, it idled up and over everything I pointed it at, and down the same hills and obstacles without running away. Compression breaking is amazing with the Diesel engine and the Rubicon transfer case. These will definitely come in handy in Africa!



After driving it across the country, and some around home, we love the conversion. On the open road, it drives like a dream. Anything over 40 MPH has you in 5th gear anyway, so you pick a speed and hold your foot in it. Small throttle modulation are all that is needed for climbing hills, passing, or descents. While cruising, the engine noise is only slightly higher than stock, with wind noise from the roof rack louder than the engine. I have come up with some observations on how it drives.
Never use first gear, it is just too low.
Even second is little more than an excuse to get to third.
Starting at an intersection in second, I am shifting to third halfway across the intersection.
Third is good for neighborhoods, or getting to 4th.
Anything over 25 MPH is done in 4th gear.
4th and 5th gears are the two most used gears.
It is most comfortable between 60 and 65, with 70 within reach but really used for passing.
The ride is smooth and just a bit better than stock. It soaks up potholes and frost heave without jostling the occupants at all.

Off road, it is a beast! While it won't win any races, it will get where ever you point it, letting nothing stand in it's way. Throttle control is super smooth and easy, allowing for minor modulation to get over any obstacle with ease. Up or down hill at an idle is easily achievable. My father in law put it best when he said "I don't think you will need a winch on this! Take one just in case, but you will probably only need it to pull other people out." I think he is right, it just crawls over rocks and out of holes with ease.

It also gets a lot attention! People constantly ask us about it in parking lots and give us thumbs up on the road. When they hear it, or realize it is a diesel, they get really curious! We have met countless people who want to know all about it and how we got a diesel Wrangler. I even saw one guy stick his phone out of his window at a stoplight to snap a photo of our Jeep waiting for the light to change.
 

Comanche Scott

Expedition Leader
Sounds like a great adventure! :beer:

So the big question of the day has to be, what kind of fuel mileage your managed coming back across the country?
 

jsek29

Observer
With 4.88 differentials, we got between 16 and 19 mpg. We also had a 35x12.50 spare tire strapped to the roof. We're getting about the same running around town.

We're looking into re-gearing to 4.10 diffs as soon as Dana Spicer and Eaton release the parts, any day now.
 

Comanche Scott

Expedition Leader
Whoa, yeah that is a lot of gear for the low rev'ing 4BT.
4.10 is probably a good compromise with the standard Wrangler transfer case.
The Scout with the 4BT has 3.73 gears, but also a 4:1 transfer case. That worked out great to take advantage of the wide ratio 4L60E transmission.
I think you'll see a substantial improvement in fuel mileage with the lower gearing. It will also be much more "driveable" with a wider speed range in each gear. :beer:

In any case, I think you've proven out the reliability factor! :)
Should be a fun year.
 

jsek29

Observer
Yes, 4.88 is S-U-P-E-R low, which is awesome off road, but less than awesome on the highway. It also means I cannot do burnout so, even in gravel.

Dana only offers The Ultimate Dana 60s (bolt on fit for JKs) in 4.88 or 5.56. They are supposed to be putting other ratios on the market soon, but Eaton, who makes the carrier/locker (E-Locker), has hat to retool to make the E-Locker for 4.10 and numerically lower R&P. Hopefully they get those out sooner than later, a wider range per gear and little higher top speed would be super handy.
 

kojackJKU

Autism Family Travellers!
Did you ever re gear your rig? When you were saying that you were not using 1st and skiping 2nd asap you were geared WAY to low. You should see a great increaese in milage after a regear.
 

jsek29

Observer
I have kept my finger on this pulse, and they are not yet offering the R&P and carrier/locker for re-gearing. They are selling whole axle assemblies in those ratios, but not the parts. Yes, we are geared WAY too low, but that was the best option at the time. If we can the the parts before we ship the Jeep to Africa, we will re-gear for sure. Even if we don't, it should have a minimal impact on our trip, as we won't be running at top speed frequently in Africa.

Right now, we are working with Pronghorn Overland Gear to get a prototype rear bumper system on the Jeep prior to shipping. The system will be a dual swing out, able to carry a spare tire up to 37" or a cargo tray with 4 Jerry cans and maybe a 5 gal air tank on each swing out. The spare tire carrier will drop the tire down to ground level with spring assist so you only lift approx. 20 lbs. when dropping or lifting the tire. Yes, that's right, you could carry two 37" spares on this bumper.
 

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