5,000 rpm, 39 degrees of timing, and a “I don’t think we can push this motor any harder” comment from the owner is probably the best way to sum up Brian Robbins’ OBS Ford. And no, it’s not powered by a P-pumped Cummins.
Rather, his ’97 F-350 represents just about every performance advancement that’s been made on the 7.3L Power Stroke platform over the past decade. In addition to the 20-year-old Blue Oval’s ability to be competitive in 2.6 pulling classes, it also helps promote Brian’s Beech Creek, Pennsylvania, company: Stroked Out Performance.
While building a 7.3L that holds its own in the 2.6 class was extremely rewarding, it didn’t come without sacrifice. There was a learning curve that entailed toasting three forged rod engines before a built 7.3L was pieced together. The current power plant, which effectively brought all breakage to a halt, features a filled block, girdle and ARP main studs, Carrillo connecting rods, fly-cut and coated cast-aluminum pistons, and a Stage 2 camshaft from Colt Cams. Top end improvements include a set of full race cylinder heads from Diesel Shop LLC, as well as Smith Brothers’ chromoly pushrods and ARP head studs.
HEUI ON STEROIDS
With a set of Full Force Diesel 450/400 hybrids onboard, the engine makes use of what are essentially the largest injectors available for a 7.3L Power Stroke. The big sticks flow 450cc of fuel, utilize 400% over nozzles, and are controlled via custom tuning les written by Dan Kropinak of SDK Performance. Oil demands are met thanks to a Gen 3 high-pressure oil pump (over a stock displacement HPOP) from Swamp’s Diesel Performance. The big hybrids receive a steady diet of diesel courtesy of an A1000 lift pump forcing fuel through ¾-inch line. An adjustable Fuelab regulator sets supply pressure at 80 psi.
Limited only by air, Robbins knew turbo selection would be key in order for his 7.3L to have a fighting chance in the 2.6 class. For that, an S475-based BorgWarner was sourced from Engineered Diesel. The charger makes use of a 66mm (2.6-inch) compressor wheel inducer, a 96mm turbine wheel, 1.10 A/R exhaust housing, and sits at the rear of the lifter valley thanks to a T4 turbo mounting kit from Irate Diesel Performance. A waterto- air intercooler, comprised of two Frozen Boost units, cools off the boosted air and mounts behind the grille.
Sticking with the E4OD automatic, Robbins enlisted the experts at BTS to help him get the power to the ground. The four-speed slushbox was treated to 300M shafts, a cryogenically treated transmission case, and a Precision Industries triple-disc torque converter with a 3,000-3,200rpm stall speed. A shift box, designed by industry friend and longtime 7.3L enthusiast Matt Maier, allows Robbins to control lockup via toggle switch.
Brian Robbins will be the first to admit that trying to make a 7.3L Power Stroke competitive in a world dominated by mechanical and common-rail trucks is a tall order. But with several second- and third-place finishes under his belt throughout the 2016 season— against Cummins and Duramax pullers making twice the horsepower, no less—Robbins’ combination of parts is proof that it can still be done. While he knows the odds will never be in his favor, he’s quick to point out that a 7.3L can be made to keep pace with the big boys. “It might not win every day, but it can be competitive,” he told us. And that’s exactly why he continues to show up and shred dirt.