A 700HP, Cummins-Powered OBS Ford
It’s true that you don’t have to spend big money to build the truck of your dreams. Even though Tyler Turay lightheartedly refers to the project shown here as a financial mistake, his ’95 Ford F-250 is actually living proof of that statement. A self-taught fabricator and no stranger to using a wrench, his changing tastes have influenced the look of his OBS Ford tremendously over the last 10 years—and doing nearly all the work himself has saved him a boatload of money. First, a Dana 60 replaced the factory Dana 50 TTB, six inches of lift was added, and the truck rode on 38-inch Mud Grapplers. Then came the ’05 axle swap, a leveled front-end, and 35s. Most recently, the old-school ¾-ton was lowered and graced with Toyo Proxes. Of course, the biggest change took place when Tyler ditched the 7.3L Power Stroke in favor of a P-pumped Cummins back in 2013.
7.3L Out, 5.9L Cummins In
After encountering multiple electrical gremlins with his modified-yet-aged 7.3L Power Stroke, Tyler came across a ’92 first-gen take-out engine listed on Craigslist. Because he had a strong desire to simplify the truck and make more horsepower—and the Cummins could be had for just $1,500—his mind was made up. However, knowing the first-gen Cummins’ VE injection pump would never provide the kind of fueling he was after, he sourced a P7100, front cover, injection lines, and everything else he’d need from a Ford F800 and went to work. The 265,000-mile, P-pump-equipped 5.9L was swapped in and life was good, for a few years anyway…
Mandatory Engine Build
When disaster struck just three years into the swap (the camshaft had split in two and summarily led to the valves meeting the pistons), Tyler was forced to rebuild the Cummins. On top of the standard machining performed on the block and head, he opted for ARP main studs, ARP rod bolts, and Mahle standard bore marine pistons. He also O-ringed the head and added head studs as reinforcement measures. A drop-in, 188/220 Hamilton camshaft, stiffer valve springs, 24-valve tappets, and heavier-duty pushrods were also part of the engine’s makeover.
No Shortage of Fuel
Tyler’s path toward 700 rwhp began by making all the usual tweaks to the 12mm P7100. Grinding down the factory fuel plate to a #0, modifying the AFC, adding 4,000-rpm governor springs, a Mack rack plug, 7mm delivery valves, and a TorkTeknology adjustable overflow valve help wake the 175hp pump up tremendously, while a FASS system and a dual feed line kit keep it supplied with plenty of fuel. Contagious Diesel 5×18 injectors with SAC-style nozzles make use of the popular 155-degree spray angle to match the marine piston bowls located beneath them.
60+ PSI of Boost
Packing the cylinders full of air begins with an S400, equipped with a race cover and 6-inch to 5.5-inch air intake that Tyler fabricated. The sizable single employed a billet 67.7mm compressor wheel, an 83mm turbine, and a fairly loose 1.10 A/R exhaust housing. It mounted to a T4 Steed Speed exhaust manifold with a 1-inch T4 spacer between the two in order to clear the race cover. Per Tyler’s Auto Meter analog gauge along the A-pillar, the engine sees more than 60 psi of boost at full steam ahead. Boost is routed through an aluminum 7.3L Super Duty intercooler before making its way into the engine.
47RE & Manual Valve Body
With the kind of hard-earned miles Tyler planned to put on the engine, erring on the side of an overbuilt transmission was more than justifiable. Making the four-speed 47RE darn near indestructible, it was treated to all billet shafts and a billet direct drum, Raybestos clutches, and a billet stator, 3D race converter—all from SunCoast. The converter’s 2,500-rpm stall speed lights the S467.7 perfectly and the use of SunCoast’s manual valve body places every shift in Tyler’s hands. A remote mount, external filter, 6.0L Power Stroke transmission cooler, and deep PPE pan keep fluid clean and cool. As a matter of fact, Tyler tells us ATF never crests 150 degrees.
So what’s it like to drive a 5,900-pound, Cummins-powered old body style Ford with 700 rwhp on tap? Let’s just say Tyler finds himself in his fair share of impromptu drag races, and we hear roll-racing is one of his specialties—which isn’t something you see a lot of big, single-turbo diesels excel at. Beyond the breakneck power of this 11-second daily driver is an owner who built it himself. “I did 90 percent of the work in my driveway until I started working at LinCo Diesel Performance,” he told us. “I even did the body prep work myself—outside—before it went in for the Sterling Silver Metallic paint.” Whether he’s hunting down Corvettes, commuting to work, or just enjoying the coil-sprung ride, Tyler’s Cummins-powered OBS creation has the perfect blend of modern diesel muscle and old-school looks.
1995 Ford F-250
Owner: Tyler Turay
Hometown: St. Charles, Missouri
Odometer: 223,000 miles
Engine: 5.9L Cummins
Short Block: Fresh overhaul with polished crankshaft, ARP main studs, factory forged-steel rods with ARP rod bolts, cast-aluminum Mahle marine pistons, Fluidampr
Head/Valvetrain: O-ringed head, Hamilton Cams 188/220 camshaft, 24-valve tappets, Hamilton extreme duty pushrods and dual valvesprings, ARP head studs
Fuel: Bosch P7100 with #0 fuel plate, modified AFC, 4,000-rpm governor springs, 7mm delivery valves, Mack rack plug, dual feed line kit, TorkTeknology adjustable overflow valve, Contagious Diesel 5×18 injectors, FASS Titanium system, 38-gallon tank with sump
Air: BorgWarner S467.7 with race cover and 1.10 A/R exhaust housing, custom 6-inch to 5.5-inch air intake, fabricated intake elbow, 7.3L Power Stroke intercooler
Exhaust: Steed Speed T4 manifold, 4-inch downpipe and exhaust, 7-inch tip
Electronics: Edge Insight CTS2
Transmission: 47RE with billet input, intermediate, and output shafts, Raybestos clutches, Sun Coast billet direct drum, manual valve body, billet stator 2,500-rpm stall 3D race converter, and billet flexplate, 6.0L/5R110 transmission cooler, external filter, PPE deep pan
Horsepower: 700-rwhp (est.)
Torque: 1,300 lb-ft (est.)
Tires: 305x50R20 Toyo Proxes STII
Wheels: 20×10-inch Lonestar Outlaw
Axles: ‘05 Super Duty Dana 60 with 3.73 ring and pinion (front), ‘05 Ford 10.50 with 3.73 gears and ‘08 diff cover (rear)
Suspension/Steering: ‘05 Super Duty Harley Davidson edition front coil springs and radius arms, Ballistic Fabrication universal track bar mount, Rancho shocks, homemade traction bars