Peterson Fluid Systems is proud to make one of the best performing and most versatile oil pumps available in motorsports. The R4 Oil Pump is the result of more than 50 years of fluid engineering and racing experience. Peterson pioneered the twisted lobe rotor design to deliver solid oil pressure, even in high-temperature low-viscosity oil applications, and it can pull serious vacuum too. R4 provides heavy-weight performance without the heft: shallow depth screw-in fittings, profile machining, and aluminum rotors make the R4 one of the lightest pumps available. The pump's steel drive shaft is 5/8" with a 3/8" machined male hex for cam or accessory drives. All R4 pumps have a rear drive provision that allows for the direct mounting of many popular drive accessories like fuel pumps, vacuum pumps, or power steering pumps with the appropriate adapter. The most discerning engine builders trust the R4 Oil Pump to protect and extend the working life of their engines by having the proper pressure and volume when crucial. Maximizing horsepower with the pump’s ability to create crankcase vacuum as it scavenges and reduces windage in the oil pan is a hallmark of the R4. Equally at home on a 5-second drag car, endurance racing at Le Mans, punishing deserts of Baja, or even at the local dirt track, Peterson has an R4 oil pump to ensure a first-place finish in any race.Proudly made in the USA, all pumps are engineered, machined, assembled, and tested in-house, in Longmont, Colorado. Custom configurations are available. Contact the Peterson Fluid Systems sales and customer service team for additional options.