Automotive

This Chrysler Engineer Is Shoving A 485 Horsepower Hemi V8 Into A Jeep Scrambler

By TechKee Admin

Posted on May 10, 2018

Fiat Chrysler engineer and passionate car-nut Ben Reedy spends his days engineering new cars, and his nights wrenching on old ones. His latest project involves shoehorning a 485 horsepower, 6.4-liter Hemi V8 out of a wrecked Challenger into his 1983 Jeep CJ-8. The whole thing is truly epic.

Before we jump into the build, a bit about Ben’s background, because it’s an interesting one. He grew up in Wyoming, and joined the army after high school before using the G.I. Bill to study mechanical engineering at Kansas State University. From there, he was accepted into Fiat Chrysler’s selective “Chrysler Institute of Engineering” rotational program. Having finished the program and earned a master’s degree, Ben currently works as a JL Wrangler transmission shift quality calibration engineer (that’s his development vehicle we blurred out in the photo above).

But it’s what he does after work that interests us today, because Ben is building one of the most badass Jeeps I’ve ever seen—even more so than the turbodiesel Jeep Grand Wagoneer that he sold to make way for this new project. “I wanted my own project to build, and with grad school being done I thought this would be a good way to keep me busy,” he told me over Facebook messenger. He went on to say that the whole point of this endeavor is to “build a vehicle I truly wanted, and not have to sacrifice because I can build it to my specifications.”

The Jeep started as a beautifully-running, 63,000 mile 1983 Jeep CJ-8 Scrambler with a 4.2-liter inline six mated to a T176 four-speed manual, sending power to a Dana 300 transfer case, an AMC 20 rear axle and a Dana 30 up front. The paint looks great, and the body—having been replaced by a fiberglass tub and fiberglass panels—is immaculate.

But well before the CJ ever came into the picture, the project began with a motor (like all great engine swap projects do). That motor, shown below, is a 485 horsepower 6.4-liter Hemi V8 out of a 2015 Dodge Challenger. When Ben learned how little an Auburn Hills-based engine shop called Arrow Racing Engines was asking for the motor, he snatched it, and began thinking about which vehicle he wanted to shove it into. Ben wanted a CJ, but wasn’t sure which one.

“I decided I wanted to put [the motor] in an old CJ because as a kid I always wanted a CJ, and that’s the only vehicle I would have sold the Wagoneer for,” he told me, going on to describe his thought process for going with the CJ-8 versus other CJs. “When it came to packaging, the older Jeeps were out of the picture,” he said, “because to get [the engine] to fit with the length of the drive train would have left my drive shafts too short.” That left Ben with the CJ-7 or CJ-8 as the only options; he went with the latter, because—come on—how often do you spot a CJ-8 on the road?

When I first stopped by Ben’s place in January, the project looked—how shall we say—“ambitious.” The fenders and grille were off the Jeep, and the engine bay had just been gutted, with the old engine and trans sitting on the ground. The only new part that I could spot on the Jeep was the brake booster. Ben told me he hoped to have this Jeep ready for the Woodward Dream Cruise in August—the quintessential wrenching deadline for Motor City gearheads—and I must admit, I was skeptical.

Here’s the 258 cubic-inch inline-six and four-speed out of the CJ-8.

But even if the Jeep looked like it was in shambles, Ben had actually done quite a bit of work on the powertrain. Sitting on a pallet, squeezed into the small garage near the Jeep, was the new Hemi engine, already bolted to an NV4500 five-speed transmission out of a 1998 Dodge Ram 2500. Fastened to that trans was the CJ-8’s original Dana 300 transfer case—a transfer case known for its durability.

Ben had cracked open the NV4500 transmission, replaced a worn input shaft, as well as the bearings and seals. He had also put new seals and bearings into the Dana 300 T-case, as well as a shallower front bearing retainer so that it would mate up properly with the transmission.

Ben didn’t do much to the motor. He says Arrow Racing Engines had pulled it from a running vehicle, and—after removing the oil pan to look at the bottom end (and also to replace it with a 5.7-liter V8 pan, which has a rear sump that can clear the CJ’s solid front axle) and peeking at the cylinders through the spark plug holes—Ben concluded that everything appeared to be in decent shape. “We will find out,” he said when I asked what shape the motor was in.

I guess you could say he’s going to “send it.”

After throwing in a new flywheel and clutch, Ben bolted the transmission, transfer case and motor together, and gave them a nice coat of black paint. When I visited back in January, Ben was working on having the Novak motor mounts welded into position.

Yesterday, I visited Ben to see how progress was going, and I was blown away. Not only was the powertrain bolted into the Jeep, it was done extremely well. The engine bay literally looks better organized than it did with the original motor.

It’s quite fascinating the way Ben got everything to line up. The V8 engine is shorter than the inline six that came out of the CJ, but the rear of the transmission is about five inches longer, meaning the transfer case sits five inches further rearward. So Ben simply moved the transmission crossmember back (using already-existing holes in the frame behind the standard holes) and drilled two new holes into the crossmember to line up the transmission mount.

“I had to move the [transmission] cross member to the rear most holes [in the frame] and then drill new holes just aft of the stock ones [in the crossmember] to get it to line up,” he told me. “You can tell the transfer case is what moved the most back because that’s where I had to cut the tub a little more to be able to shift into 4hi.”

The transmission shifter lines up perfectly with the hole in his body tub, though you can see below that he had to do a bit of trimming for the transfer case shifter:

With the shifter cover and boots in place, that’s going to look great, which means it will match the rest of Ben’s packaging, because it all looks phenomenal. Just look at this engine bay:

From every angle I looked at this thing, the packaging not only looked good, but appeared to still offer enough space to make servicing this rig relatively painless:

Sure, the oil filter will probably drip some fluid onto the front axle during an oil change, and Ben might have to jack the motor up just a hair to get one of the alternator bolts out, but for the most part, wrenching shouldn’t be a problem.

As far as electronics goes, Ben says Arrow helped him figure out how to use the ECU to merge the 6.4-liter’s harness with the Jeep’s factory harness. This will allow him to use the Jeep’s stock gauges, fuse box and switches.

Because the 6.4-liter is a drive-by-wire setup versus the bowden-cable configuration that the CJ had originally, Ben picked up a gas pedal, and bolted it up under his dash.

Of course, it looks great.

As for accessories, Ben’s using the water pump that came with the motor; that pump will feed a three-core aluminum radiator with two electric cooling fans, for which Ben still needs to install a thermal switch into his cooling system. Ben will also use the stock Challenger power steering pump and alternator, all of which package fairly well in the engine bay.

With help from Arrow, Ben got his exhaust Y-pipes, though he still needs to finish the full routing; he hopes to install electric exhaust cutouts to let the motor roar when the time is right. Which is most of the time.

You may have noticed in these images that the front of the Jeep sits a bit taller than the rear. That’s because Ben just finished installing an Old Man Emu 3.5-inch lift kit on the front stock Dana 30 axle. That lift, with its wide leaf springs, was actually designed for the Jeep Wrangler YJ (the one with the square headlights), but Ben converted the CJ over for a bit more stability.

The rear lift, which will bolt underneath a beefy Ford 8.8-inch rear axle (which Ben says will be a bit wider than the stock axle), still needs to be set up. Both axles will have differentials with 3.73 gear ratios.

There’s still plenty of work to do, including routing brake lines, installing a custom exhaust, bolting up a Ford 8.8 axle, finishing the lift kit, and getting all the wiring done. But as it sits, the project looks promising.

Many engineers cannot wrench on cars; I’ve said before that engineers are not necessarily mechanics. But, as this project proves, an engineer who can wrench is an unstoppable force. Because this thing, once complete, is going to be total madness on the straights of Woodward.

Check out this picture gallery for a closer look at the Jeep: