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Scouting Kaufman: An Inside Look at the Aaron Kaufman Scout Build

Posted in Features on June 28, 2018
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Photographers: Brooks MartinArcLight Fab

If you’re a gearhead, you know the name Aaron Kaufman. The Bearded Wonder! For five years and over 100 episodes, Aaron was the mechanical muscle of the Fast N’ Loud TV show, turning Richard Rawlings’ vehicular ideas into reality. He was Richard’s top gearhead for many years before that. At the end of the 2017 season, Aaron left the show to start his own shop, ArcLight Fab, so he could focus on his own ideas. This change led to a new Discovery Channel show for 2018: Shifting Gears With Aaron Kaufman ( Four Wheeler got an inside look at the show’s first project.

For the very few of you who haven’t seen Fast N’ Loud, there was some 4x4 content, but Aaron had an itch to explore that side of the buildup world a bit more. The specific itch he wanted to scratch was a high-performance all-rounder; a rig you could comfortably wheel to the trailhead, do a hard-core trail, and drive home. When it came time to pick a rig, he wanted something uncommon with just the right “look.” He settled on an International Scout.

How can you describe Aaron Kaufman? At 36, he’s still at the leading edge of his prime, but he has put more exciting gearhead times behind him than most guys twice his age. He readily acknowledges “living the dream.” In our dealings with him, we found Aaron to be unfailingly courteous with everyone he encounters, funny, knowledgeable, and well spoken.

“I’ve always been curious about International Scouts,” Aaron said, “and the more I learned about them, the more interested I got.” After deciding to go Scout, the next step was to find one with the parts he needed, and so he put out feelers. His good buddy Chris Russman came up with a semi-derelict ’71 Scout 800B Comanche. If you are knowledgeable about Scout history, you will know the Comanche was a limited production promotional special made very briefly in the ’71 model year before the new Scout II debuted. Aaron didn’t know how rare this rig was until much later, but the purist collectors who began sharpening pitchforks and knotting up nooses were somewhat mollified to know that it was the least desirable version (six-cylinder, three-speed manual), was missing all the “unobtainium” parts, and had been severely rolled—not to mention it had sat for a couple of decades. In the end, all Aaron used was the body. The chassis and unused parts went to keep other vintage Scouts rolling.

Then, some strange wild hairs started growing and a new itch needed to be scratched. During a visit with Casey Currie at Currie Enterprises, Aaron discovered Ultra4 racing. Ultra4 is a new flavor of off-road racing, whereby a vehicle can be at 100 mph over desert terrain like a Baja racer one minute, then creeping and crawling at 1 mph over insanely huge rocks the next. With a lot of the build executed, it was way too late to switch over to a scratchbuilt Ultra4 project, but could the Scout project shift gears enough (pun intended) to go racing at Hammertown?

The best side of the ’71 International Scout Comanche only hints at the abuse and neglect this rare Scout suffered over the years. Less than 1,500 of these were built from November 1970 to March of 1971. They were mostly a paint and decal special, with just a few special parts. They came with either a 232ci AMC six, which International called the “Power Thrift” and was the same engine Jeep began using in 1972 and later CJs, or International’s 304ci V-8, which was essentially a medium-duty truck engine. This one was a six with a three-speed manual, the least desirable combination.

First, it had to be decided into which class the Scout fit. That was determined to be Class 4400, which is an unlimited class. “Unlimited” means that class regulations and build directives were few, so the Scout could play, but it also ensured the Scout was going to be fighting way out of its class and would be up against some of the best drivers and most awesomely built buggies. Well, that guaranteed no trophy, but certainly offered the experience of a lifetime and a challenge for the ArcLight crew. Aaron later described it as, “Bringing a paper clip to fight a gun battle.”

Anyone who competes in motorsports knows the driver makes for 75 percent of a race rig’s success. Aaron has a broad level of experience in different types of competition and has the basic skills to do just about anything, but he had little specific experience four-wheeling. To that end, he consulted a variety of experts in the field for advice and got some specific training when he could get time away from the build.

It took about 100 days to build the Scout. A hundred days of late nights, weekends, and enough caffeine to bring the dead back to life. The crew left the shop in Dallas just a few days before the start of the race with a rig that had little more than a few runs up and down the block…and on some of those runs it had to be towed back! Much of it was typical shakedown things that any new rig experiences. Others were more serious problems that they worked on right to the minute the Scout was loaded onto the trailer.

Kaufman’s band of brothers encompasses a wide variety of skills and an almost unstoppable level of energy. From the left: Jonathan Mansour, Jon Rodriguez, Jeremy Webster, Josh Freeman, and Jason Bowman is on the far right.

Upon arriving at Hammertown, the dialing-in continued on both the Scout and its driver. The ArcLight crew continued tweaking the vehicle and the driver absorbed as much of the unfamiliar driving environment as he could. Experienced Ultra4 driver Brian Tilton allowed him to co-drive in his 4800 class rig, leaving the crew 36 hours to dial in the Scout. If you watched the show, you will know that it was all to no avail.

Aaron, with Jason Bowman as co-driver, started out on Friday over a 202-mile course, and they were given 14 hours to complete it. They made it all of 26 miles before a cascade of failures stopped the Scout. Transmission programming had been the deranged gorilla in the room from the very start. The trans just would not shift properly and was always in the incorrect gear. It was a case of an overly complex transmission coupled to a low-tech diesel and no track record anywhere to fall back on for help. Out on the course, it soon began overheating and reached a terminal temperature. The trans problems were complicated by issues with the diesel, which lost power, was rolling smoke like a coal- powered locomotive, and sucking fuel like a 1,200ci marine diesel. It was later calculated to be delivering one mile per gallon due to issues with the compound turbo. At 26 miles, the 26-gallon tank ran out of fuel, and with outside help forbidden by the rules, that marked the end for the ArcLight crew. If the Scout had not run out of fuel, the trans probably would have smoked itself to death before the end of the race. Aaron took the blame on camera, acknowledging a bad choice in the engine and transmission combo.

What’s next for the ArcLight Scout? Aaron cogitates as they move on with other builds. Mostly likely, it will get a 4L80 with a manual valvebody. This is a proven combo with the 4BT. It might also get a manual trans. A fix for the diesel should be a bit easier. It could still get the all-rounder treatment, so stay tuned to Shifting Gears With Aaron Kaufman for the latest.

It only took the ArcLight crew a couple of hours to strip the Scout down and get the parts they wanted…namely the body. Here, International Scout Encyclopedia author, Jim Allen, discusses the finer points of Scout history with Aaron. Though Aaron doesn’t do many restorations, he is keenly appreciative of that process and automotive history.
Modifying the Scout body to accept 40-inch tires while still retaining the essential body lines was one of Jeremy Webster and Josh Freeman’s main jobs. After cutting out the eyebrows, Freeman fabricated new sections and after a few trial fits; Aaron approved the look. Little did they know all that fine work would be undone after the suspension was tested.
The chassis was a blank slate, so Aaron designed one to fit the body and, with his expert team, built it. Baileigh Industrial’s MB-4x2 mandrel bender is one of the few out there that can bend 2x4 rectangular tubing. The ArcLight team used 0.120-inch DOM tubing from Race City Steel, and there was no shortage of expert welders in house to put the pieces together.
After several test-fits to the body, the chassis was complete. The body was tweaked, but the stout chassis pulled it straight.
Industrial Injection built up a mid-’90s 3.9L 4BT core, and Aaron and some of the Industrial Injection crew check it out here. From left to right are Aaron, Dustin Hembury, Tyler Kipp, and Bob Millican. The connecting rods were polished and ARP bolts were added. The block was bored 0.020 inch and Mahle 17.5:1 CR pistons were added. These have the Performance Diesel Machine (PDM, a part of Industrial Injection) ceramic-coated skirts and thermal barrier coating on the crowns. The rotating assembly was balanced and Industrial Injection’s 4BT main girdle kit added for the ultimate lower end beef. The cylinder head was ported to deliver maximum flow and fire-ringed to contain high levels of combustion pressure. It’s held down by beefy ARP studs. The valves use 150-pound springs and are popped by a PDM Stage 2 cam. Industrial Injection’s Dragon Fly Bosch P-pump with 12mm plungers (can supply up to 470ccs) supplies fuel to 5x0.018 injectors (five 0.018-inch orifices). Airflow comes from a compound turbo setup that uses a 57mm T3 manifold turbo and 66mm T4 turbo for the atmospheric unit. In this configuration, the 3.9L 4BT makes 385 hp @ 3,000 rpm and 625 lb-ft of torque at 2,700 rpm.
A shotgun wedding! To ArcLight’s knowledge, a 4BT has not been married to a GM 6L80E until this project. It’s not just any 6L80E but a Monster Transmission 6L80E SS Super Duty automatic transmission, which includes all-new high-performance clutches and steels, bearing, thrust washers, and valvebody upgrades. It’s the strongest version of that automatic Monster builds, able to handle up to 750 hp. The converter is a custom-sized Thor with an 1,800-2,000 rpm stall against the 4BT’s torque. The Thor has a billet lid, multiple clutches, and is furnace brazed. The OE electronic valvebody was swapped out with a TEHCM unit, which improves functionality. It’s essentially a stand-alone transmission computer.
An Atlas G2 Pro Series (A.K.A. “Race Case”) transfer case from Advance Adapters spits the power front to rear. It uses the 3.8:1 low range and has 300mm input and rear output shafts, as well as the 1.5-inch cluster pin. Adapting it to the 6L80E took a little custom work. This transfer case is ever-present on Ultra4 racers because of its extreme beef.
Jon Rodriguez installs Pro-Touring full-float unit bearings on the Currie Enterprises F9 3.5 rear axlehousing. The housing is fabricated with 3/8-inch Hi-Form 50 plate and 3.5-inch, 0.250-inch-wall 4130 steel tubes. The Pro-Touring unit bearings are used front and rear with a 6-on-5.5 wheel bolt pattern and 5/8-inch race studs.
The front housing has 1-ton steering knuckles. The carriers in both axles are the legendary Currie nodular housings carrying ARB Air Lockers and Motive Gear 4.56:1 ring-and-pinions. Axles are 4340, 35-spline all around. There is a bit of history here too. Currie Enterprises started in 1959, and when the business grew into the 1960s, Scouts were one of the first 4x4s for which they supplied 9-inch axle conversions.
The suspension uses a three-link coilover setup up front and four-link coilovers in back. The system uses 2.5x14-inch remote-reservoir bypass King Shocks with 350/400 lb-in spring rates up front and King 2.5x16-inch shocks in back with 450/500 lb-in springs. The front has 12 inches of travel and the rear 16. Two-inch King bumpstops were used at both ends. You can also see the Currie AntiRock sway bar above Aaron’s head.
The rear trailing arms were fabbed at ArcLight. The place is full of “hot-glue-gun” masters.
The Scout has plenty of “whoa-power.” ArcLight used Wilwood brakes front and rear, the rear shown here including the MC4 cable-operated parking brake kit. The slotted, ventilated rotors are 14 inches in diameter and 0.810 inches thick. The six-piston calipers have nickel-plated bores and are fitted with PolyMatrix E pads, which are middle temperature range pads Wilwood has determined work well in Ultra4 racing. Interestingly, the brakes are identical front to rear and have no bias at all. Wilwood has determined that in this form of off-roading, equal braking leads to less drivetrain breakage. Wilwood also supplied a tandem aluminum 1 1/8-inch-diameter master cylinder (which is attached to a vacuum power booster).
The ArcLight crew needed to hit the ground running when it came to the wiring, and Racepak came to the rescue on so many levels. For a start, the company’s Smart Wire system eliminates traditional fuse boxes and wiring, using a Power Distribution Module (PDM) that electronically controls and monitors every circuit to which it is connected. It can be connected to a digital display that can show engine parameters and a variety of other functions. For the Scout, they opted for two displays: one for the driver and another for the co-driver. Each can be programmed to display what each needs to see.
The dash was custom-built to carry two Racepak displays in two very vintage-looking surrounds. And, yes, those are A/C ducts. These are a legacy from the original project idea for an all-around 4x4. The A/C works, by the way!
File this under “best-laid plans of mice and men.” The lovely work done by Josh and Jeremy on the front fenders had to be hastily redone after the suspension was cycled. Whoops! The tires hit.
When it was all said and done, Josh and Jeremy’s quick work turned out great. Note the Bulldog Alpha competition winch, which is a fast 55-fpm electric with a short drum that carries 75 feet of premium synthetic rope. KC supplied enough lights to turn night into day, including a Gravity lightbar up high and a pair of 7-inch Gravity LED DOT-legal headlights.
If you’ve watched Aaron’s show, you will know that it always ends in a mad rush to get the project complete and ready for the task at hand. As you can see, that precluded a lot of pretty-up stuff. It’s wearing the original patina and has a sort of a “rat-rod-racer” look. Most of the fabricated metal parts on the chassis are unpainted.
The Scout arrived at Hammertown completely untested. The first practice runs uncovered a lot of problems. One among the many that could be fixed in the field was shock tuning. With the help of King Shocks, they got that aspect resolved.

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