Mistaken as a 4BT by some, immediately recognized by others, the 4.5L Powertech makes the John Deere theme 100-percent authentic. Obtained off of ebay, the 1,000-pound, cast-iron block and head inline-four is set back roughly 4-inches for more favorable weight distribution, ultimately resting on Summit Racing motor mounts. Believe it or not, the serpentine belt system sold Jody on the engine more than anything else (many were V-belt). As it turns out, this specific Powertech previously served in a genset application, which meant a governor change was in store in order to make the engine street-friendly.
MECHANICAL FUELING
Fuel system reliability checks in in the form of a mechanical injection system that’s based around a Stanadyne DB4 rotary pump. After taking a trip to Area Diesel Service, the pump’s governor was reworked for street-use, and it was also modified to flow 45-percent more fuel. The DB4 routes fuel to four mechanical injectors, which were reworked internally at Area Diesel and set for a higher, 240 bar pop-off pressure to complement
No, it’s not a 4BT Cummins painted up in John Deere Green, it’s an actual John Deere engine. Plowboy Diesel’s Jody Mollet located the 4.5L Powertech ‘Deere, which served in a gen-set in its previous life, on ebay. Various versions of this little four-cylinder have been manufactured over the years, but the rotary pumped and fixed geometry turbo version means it’s emissions free and equipped with a simple, 2-valve cylinder head. The iron block and head Powertech mill features a 4.17-inch bore, a 5.00-inch stroke, forged-steel connecting rods, and wet sleeve cylinder liners. It tips the scales at 1,000 pounds (roughly the same as a 6BT Cummins), and in this case is set back 4-inches to help with weight distribution.
The atmosphere turbocharger was sourced through Area Diesel Service, as well as several adaptors, flanges and clamps that were required to make the compound system work. The Borgwarner S300SX3 sports a 60mm compressor wheel, a 68mm turbine wheel, and a .88 A/R exhaust housing with a T4 open volute turbine inlet. Vibrant boots and spring-loaded, T-bolt clamps help hold down the fort when the compounds are under boost.
Like a lot of Jody’s projects, the engine is fitted with a compound turbo system. The original Borgwarner S2A, which makes use of a 42mm compressor wheel and a 53mm turbine wheel, was left alone on the exhaust manifold to serve as the highpressure unit. Back behind the firewall on this side of the truck sits the vacuum brake booster and the brake master cylinder.