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Part 6: 2018 Ultimate Adventure Derange Rover

Posted in Ultimate Adventure: 2018 on September 18, 2018
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When is a crate engine not just a crate engine? When it comes with just about enough parts to run in said crate. Lots of folks dream about an engine swap, whether it be a junkyard LS swap or a fuel change to a turbodiesel for efficiency and torque. And while there are tons of options out there for vehicle repowers, for Ultimate Adventure 2017 we built a 1971 CJ-6 (The UACJ-6D) with what at the time was a preproduction Cummins R2.8 four-cylinder turbodiesel. It flat-out worked.

Fast-forward a year and it was time to build another UA rig. The Cummins R2.8 was now a production crate engine, and Cummins was back as the Official Turbodiesel of the UA.

Cummins builds engines for lots of companies, including big OEMs like Ram and Nissan, tractor companies, generator companies, big-rig companies, and RV coach builders, so you can bet that when Cummins decided to build a crate engine for auto enthusiasts to put in 4x4s (or, heck, any vehicle) the product would be affordable, reliable, easy to install, and figuratively polished. And as we alluded to, this “crate engine” is more than just a long-block ready for you to add thousands of dollars of accessories, fuel systems, tuning, sensors, and gauges. This thing is almost ready to go, and when it does it runs clean, makes torque.

Ours has the newest R2.8 tune that retains the 161 hp of the UACJ-6D’s preproduction R2.8 but ups the torque from 267 lb-ft to 310. It’s a big difference you can feel since the torque curve is about as flat as a billiard table. Plus, the R2.8 comes with tons of parts, an owner’s manual, an installation guide, and a two-year warrantee from Cummins. Power, mileage, and guaranteed longevity, all for a reasonable price? Sign us up!

Out with the old and in with the new. The original aluminum 3.9L V-8 that came out of the Rover would run on ether, but it sounded horrible and most of the EFI wiring harness looked rotten. At the same time the engine and heads look new, and there were several glue-on temperature sensors that engine rebuilders add so you can’t run it super-hot and then bring it back for another when it blows a gasket, indicating a recent engine replacement from a mass rebuilding company. Editor Hazel wants to steal this engine and install it in his Project Why-J 1989 Wrangler to see if it’s toast or not. We’ll let you know.
The Cummins R2.8 Turbo Diesel has to be one of the best crate engine deals out there, hands down. We don’t just say that to be nice and fluff Cummins. For under $9,000 this thing comes with just about everything you need to make the engine run. We even got ours to run in the crate long before we swung it through the air and into the Derange Rover (see the video).
Does your crate engine come with a fuel system, computer, wiring harness, serpentine belt, fuel filter, and even these little fuel fittings to make installation that much easier? Cummins has been very hands-on with this program to help enthusiasts get their engine in place and running. The engine even comes with a Murphy gauge, which not only tells you engine telemetry data but also has onboard diagnostics and “check engine” lights.
Here is the fuel filter with a priming pump. Above it is the mass airflow sensor (MAF) that comes with an air intake tube with a MAF mount.
This engine comes with not only an owner’s manual but also a phonebook-sized installation manual (albeit a phonebook for a small town). This book is loaded with details on how to install the R2.8.
Axis Industries specializes in R2.8 swap components and supplied us with its R2.8 Engine Side Mount Kit. This kit comes with black powdercoated steel engine side mounts that bolt to the R2.8 block, and a pair of rubber isolators to help absorb engine vibration. Axis also has ports for coolant temp and oil pressure sensors, brackets to move the R2.8 intake, and brackets to mount the oil filter and fuel filter. Axis is on the cutting edge of engineering adapters and parts to make conversions like this easy.
For the frame-side motor mounts we fabbed up these 2x3x0.188-inch bits of rectangular tubing and plate. Since we are swapping the front axle from a driver-drop to a passenger-drop style, our mounts cheat the engine over to the passenger side as much as the relatively narrow framerails allow. The flat plate will be welded to the angled side, and the step will meet the top and sides of the Range Rover’s cleaned framerails. More gusseting will be added to the motor mounts once the shock towers and steering box are in place.
As the Rover got further along we stabbed the Cummins R2.8 in front of a 2001 Jeep NV3550 using Axis Industries and Centerforce Clutch parts. The R2.8 in the Rover is testing a 310 lb-ft torque and 161 hp. You can also expect great fuel economy (like 20 mpg or more depending on weight, gearing, and tire size), Cummins reliability, and clean exhaust emissions.
In order to have the Derange Rover run, we took the original tank and had it boiled out locally. We also fitted this bit of 3/8-inch metal fuel line in place of the electronic fuel pump that the gas engine required. With the system primed the engine-driven fuel pump pulls what fuel the engine needs to itself through the previously mentioned priming filter.
The Rover’s fuel tank placement is well designed, with the bottom of the tank sitting flush with the bottom of the rear framerails. The tank came from the factory with a skidplate, albeit a skidplate made out of rather thin steel. Knowing that the long rear overhang of the Rover would mean the tank would hit rocks on the Ultimate Adventure, we drew up some CAD files that our buddy Rob Bonney at Rob Bonney Fabrication could then cut out of 3/16-inch plate steel. These were then welded to the bottom of the factory skidplate.
As the “Holy poop, we’ve got to get this thing done!” date for UA2018 rapidly approached, lots of things happened. To cool the R2.8, we fitted a factory-replacement Range Rover brass radiator from Then we pushed the radiator back as far as possible, leaving clearance for a 17-inch reverse-rotation steel Silver Race Fan from Flex-a-Lite and using an adapter to mount it to the R2.8’s water pump from our friend Marc Terrien. To move the radiator, we drilled new holes for the radiator about 3 inches back from the factory position and built extensions for the upper radiator mounts. These radiators are held in place with two stems (like fingers) that point down to fit in rubber grommets that sink into the front crossmember. Up top are some fingers (pointing up) that are grabbed by brackets isolating the radiator with some rubber grommets. Pretty ingenious, Brits!
We also added in a bunch of 2 1/2-inch intercooler couplers and clamps from our friends at Offroad Power Products, the Official Retailer of UA2018. Add in a few lengths of 2 1/2-inch aluminum tube and the turbo is all set to force intercooled air into the Cummins R2.8. With a conical air filter on the intake tube supplied with the engine from Cummins, things are starting to seem really real.
In an attempt to ensure that the Rover stays cool at all speeds, we started to build a custom fan shroud using pink construction foam, an old UA T-shirt, epoxy, and fiberglass. So far we haven’t finished the fan shroud and the Derange Rover doesn’t seem to get hot, only on long steep climbs during Phoenix summer.


Prescott, 86301
Fife, WA 98424
Phoenix, AZ 85043
Painless Performance Products
MasterCraft Safety
Santee, CA 92071
Madison, WI
Rusty's Off Road
B&M Racing & Performance Products
Chatsworth, CA 91311
JE Reel Driveline Specialists
Rob Bonney Fabrication
Axis Industries
Legacy Products

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