JUMPING JACK FLASH
THE P-PUMPED 7.3L SHAKING THINGS UP IN THE PULLING WORLD
In truck pulling, there is no mistaking the sound of a mechanical V-8 diesel building rpm at the starting line—and there is nothing quite like a P-pumped 7.3L. It’s an engine combination that invokes nostalgia, captivates crowds, and gets Ford fans fired up in a sport that has long been dominated by Cummins and Duramax mills. Since 2003, lifelong Blue Oval loyalist and former DHRA member Ferenc X Vegh Jr. had been dreaming of one day campaigning a P-pumped version of the 7.3L instead of his HEUI-fired ’99 F-350. By 2016, Ferenc’s 16-year-old son Nathan was itching to go truck pulling, and Ferenc began to rekindle the P-pump idea. To make the dream a reality, a new truck had to be built. For that, Ferenc enlisted the same talented mechanic and fabricator responsible for keeping his old 2.8 Ford competitive a decade earlier: Will Hardesty. Working as a team, the trio has pieced together one of the most eyecatching trucks on the current Pro Stock circuit: a ’16 Ford F-350 coined Jumping Jack Flash.
With more than a decade worth of testing behind its P-pump 7.3L program, Hypermax Engineering has established itself as the unofficial headquarters for transforming the 444 ci HEUI V-8 into a mechanically injected monster. The company’s rigorously-tested engine package performs just as well in the dirt as it does on the engine dyno—and one drag racing customer has even used one of these mills to carry his Mustang into the 7s. Needless to say, Ferenc, Nathan, and Will knew exactly who to contact for a Power Stroke capable of keeping pace with the fire-breathing Cummins mills they’d be competing against.
From oil pan to turbo, the entire engine is Hypermax. This includes a factory-cast block, the company’s bedplate, forgedsteel rods with fly-cut pistons, and custom grind camshaft. A set of factory-based, cast-iron heads no longer make use of the HEUI injectors, but instead accept mechanical units that operate according to pop-off pressure. The heads also make use of Hypermax’s triple wire rings to seal combustion, bigger valves, extensive port work, billet rockers, solid lifters, Hi-Rev valve springs, and anchor to the block via ARP head studs.
13 mm P-pump
The Bosch P-pump, the heart and soul of the engine, can be spotted in the lifter valley. Courtesy of Hypermax, it’s been fitted with 13 mm plungers and barrels, a quick-rate cam, and an Ag governor. According to Ferenc, the pump is set extremely conservative for Pro Stock, yet at the same time supports more than 1,800 hp. Accommodating the P-pump is a billet-aluminum front cover, intermediate plate, and adapter plate, along with the corresponding pump hub and gear. A belt-driven transfer pump supplies adequate fuel pressure to the P-pump while eight oversize injection lines carry diesel to the injectors.
60 PSI of Boost and Ice-cold Intake Temps
In order to meet Pro Stock rules, the 7.3L is forced to breathe through a single, 3.6-inch smooth bore turbocharger (i.e. no map groove to take advantage of). And while this airflow limitation definitely seems to hold the big displacement V-8 back a bit more than it does the Cummins competition, the Jumping Jack Flash guys have made the most of it. With data logs that show 60 psi of boost, EGT that rarely exceeds 1,700 degrees, and intake temps that stay below 80 degrees thanks to an efficient water-to-air intercooler, durability isn’t being sacrificed in order to run a little closer to the front. During Super Stock or exhibition hooks, the 3.6-inch charger gets ditched in favor of a 4.1-inch unit, and the 7.3L responds very well. “When we throw the 4.1 on there, this engine really likes it,” Ferenc tells us.
Driveline & Suspension
Getting as much of the engine’s 1,800 flywheel horsepower to the Nichols cut tires begins with a four-disc Crower clutch inside a Custom Floaters bellhousing. From there, a Quick Change transfer case and Reverser combination from Pro Fab Machine transmits power to both axles. As for axles, the familiar 20-145 Rockwell can be found out back, while a Rockwell F106 resides up front. There is no suspension to speak of in the rear of the truck, but the front suspension incorporates a four-link system with a pair of adjustable coilover shocks on either side of the axle.
Only the Beginning
After a full season with zero issues or breakage in 2018 and plans to do the same in 2019, the Jumping Jack Flash crew are definitely happy with how the truck turned out. But don’t confuse happy with content. Ferenc, Nate, and Will plan to continue accumulating data, seat time, and tweaking the truck’s setup until their Ford runs at the front of the pack. With plans to hook with PPL all summer—along with select NTPA, Xcaliber, and Full Pull Productions events (and even a return trip to the National Farm Machinery Show this winter)— they’re keeping a busy schedule on purpose. Sooner or later, they could be knocking on the doors of the best trucks in the business.