Jeep Wrangler driving off-road with a 4BT Cummins engine
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Cummins R2.8 L Turbo Diesel Review

There are crate engines and then there are crate engines that rock. Weighing in at a little over 500LBS, the Cummins R2.8 is the lightest and smallest out of the ISF family. This common-rail four-cylinder produces 161 hp at 3,600 rpm and 310 lb-ft of torque at 1,800 rpm. However, the best part of the R2.8 is its broad torque curve. From 1,500 – 3,000 rpm, at least 270 lb-ft of torque is on tap. Out on the open road, you’ll get a respectable 20 MPG or better, depending on vehicle application. The Cummins R2.8’s compactness is matched by its power, making it a great choice for light-duty and light commercial vehicle applications such as pickups, vans, Jeeps, and other utility vehicles.

Off-road is where the R2.8 really excels. Chosen as the official Ultimate Adventure vehicle engine in 2017 (and once again in 2018), it powered through the desert in ambient temperatures approaching 130 degrees F. It also offered a lengthy 300 miles of range before needing a re-fuel, and it used roughly a third less fuel that its gas-powered counterparts did. The R2.8 simply motored over some of the roughest terrains with relevant ease.

Retailing for just under $9,000 when it debuted, the Cummins R2.8 offered sound bang-for-the-buck. The engine came with everything needed for a diesel swap–and was even smog legal where most local and state emissions regulations were concerned. Keep reading for an in-depth look at what you get for your money.

The comprehensive Cummins® R2.8 turbo diesel crate engine package comes with: a cam-driven vacuum pump, 120-amp alternator (internally regulated), power steering pump, wastegated Holset turbo, diesel oxidation catalyst (DOC) exhaust down tube, remote oil filter, EGR and oil coolers, full wiring harness and engine control module, and an ECU and throttle pedal. It also comes with a space for an A/C compressor, though that isn't included in the purchase price. Purchasing an R2.8 also gets you continued improvement offers and full Cummins support.

When the R2.8 arrives in its wooden crate, plastic wrapped for safety, you’ll find that the wiring harness has already been installed. The Cummins R2.8® engine has a cast iron block with serviceable sleeves (i.e. they can be replaced). This gives the engine greater strength while using less material,. The R2.8 also features a cast-iron cylinder head that employs four valves per cylinder, and that houses a chain-driven single overhead camshaft (SOHC). The camshaft actuates the valves by way of rocker arms (the short rockers are for the intake valves and the longer ones are for the exhaust valves). The rocker arms are made with heat-resistant steel and chrome plated stem, and though they have the same design, they’re not interchangeable.

As you’d expect from a modern Cummins engine, the R2.8 is equipped with electronically controlled, high-pressure Common Rail fuel injection. The high-pressure fuel pump is mounted at the front of the engine and is driven by the camshaft gear via timing chain. The turbocharger is an HE200WG Holset. The engine doesn’t come with an intercooler, but adding one is highly advantageous for most applications. The R2.8 is also equipped with start-up relief devices at low temperatures, and an electric spiral is provided for heating the air in the intake manifold.

Installing the Engine

So just how easy is it to drop one of these in?

Cummins R2.8 L Turbo Diesel Inside a Wooden Box

Cummins® R.28 Diesel Engine Image Courtesy

Although we haven’t performed an R2.8 swap ourselves, Christian Wheeler of has this to say about its drop-in nature. “When it arrives, you’ll find that the wiring harness is already installed, including the ECM (electric control module), the OBD service port, a complete throttle pedal assembly, and a J1939 CAN display Murphy gauge. The diesel oxidation catalyst (DOC) is included, as are the accessories, remote oil filter, turbo, and everything minus an intercooler and ducting.”

Christian goes on to say that, “in reality, all you need to do is hook up a couple of electrical leads, dunk a fuel pickup tube into a diesel container, and fire it up.” However, and as many of you already know, most engine swap projects aren’t simple undertakings. No one vehicle is the same in terms of chassis layout and room. You will always have to consider the style and location of the motor mounts, rear or forward sump pump positioning, turbo and exhaust manifold mounting and/or modifications, axles, suspension, flywheel housing, and the transmission. This article explains in great detail how to drop in a crate engine.

R2.8 Vs. The Mechanical 4BT Crate Engine

So, are there any negatives associated with the R2.8? And how does it measure up with the old reliable 4BT?

For starters, there’s a fine line between price and quality. There have been some complaints that the R2.8’s cylinder liners wear quickly because of the low quality of the materials used. As a result, owners often see increased oil consumption. The connecting rod bearings are also prone to failure, which can cause damage to the crankshaft. Further, the R2.8 only carries a 90-day warranty, which is a concern for many potential buyers. By comparison, our 4BT Crate Engines come standard with a 6 to 12 month, unlimited mile warranty.

For guys who want to modify the R2.8 fuel system, any sort of performance upgrades instantly void Cummins’ engine warranty. The Bosch fuel pump is completely electronic, as are the emissions control systems, which means removal of the governors, adding higher rpm governor springs and adding some 550cc, 12mm injector nozzles isn't going to fly with the R2.8.

With all electronic engines, more complexity often equals more points of failure, as well as higher repair costs and more time in the shop. With a new Crate Mechanical 4BT Engine, you get the same horsepower, more torque (370 lb-ft vs. 310 lb-ft), no emissions equipment, no electronics, and 35-plus years of knowledge on the performance modification side. The price for a mechanical 4BT Cummins is also about half the cost of the R2.8, which can be off-putting for many enthusiasts. However, for all of the rabble rousing between cousins, the R2.8 looks like a neat little engine. Only time will tell how the R2.8 performs out there on the trail or on the road.

Cumming R2.8 Specs:

Displacement2.8L (171 ci)
Cylinders4 (inline-four)
BlockCast-iron with serviceable cylinder liners
HeadCast-iron with 4 valves per cylinder
ValvetrainChain-driven, Single Overhead Cam (SOHC)
AspirationTurbocharged, Aftercooled
310 lb-ft at 1,800 rpm
Torque267 lb-ft (from 1,500 – 3,000 rpm)
Horsepower161 hp at 3,600 rpm
Bore3.70-inch (94 mm)
Stroke3.94-inch (100 mm)
Compression Ratio16.9:1
Fuel SystemBosch Electronic High Pressure Common Rail
Oil Capacity5.74 quarts
Dry Weight503 lbs
Dimensions25.1-inches (L) x 25.0-inches (W) x 28.3-inches (H)

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