Since the trend in many race-car components is to be lighter and have less rotational mass and less unsprung weight, Tex Racing of Ether, North Carolina, has debuted its newest innovation with a lightweight internal rear gear pump. Designed by Director of Special Projects Brad Francis, the pump weighs in at 1.3 pounds and is created for efficiency and improved oil-cooling characteristics.
Each pump case is machined from 6061-T6 aluminum and anodized for extra surface hardness. The precision internal gears are crafted from 8620 steel, and they are case-hardened to a Rockwell 58c reading.
Gear design promotes efficiency and provides a 4.5-gallon oil flow per minute at 9,000 rpm. Each pump is durability-tested and has shown the opportunity for fractional gains in horsepower. Gears ride on Torrington caged needle bearings that are 30,000-rpm rated.
Since the pump is internal, it eliminates the need for pulleys, bolts, lines, or brackets. The unit is driven directly off the pinion gear via a hex driveshaft fitted into the pinion. The pinion gear is EDM-machined to receive the shaft. This takes place in an oil bath so no heat is generated to the pinion during the process.
Due to its lightness and unique design, the unit provides substantially less unsprung weight mass to a race car. The difference between this pump and an external design is approximately 7 pounds, and it can fit into any Ford 9-inch case. Space for the pumps inside the housing is provided by a CNC machining process. In this configuration, efficiency is gained, because the pump effectively reduces inertia and rotational mass.
Swift gear changes are promoted with this unit, because the pump has only one fitting. That fact presents minimal obstacles when gears are exchanged.
The pump is provided to racers as a factory-installed unit or may be purchased as a separate item. Based on the cost of an external pump system, the Tex racing-pump unit installed costs around 50 percent less.
At 1.3 pounds, the newly designed Tex Racing rearend pump provides a weight reduction of approximately 7 pounds when compared to external pump units.
Light and small, the pump is designed to fit inside the rearend. When in operation, the pump is immersed in oil. Here, the pump is mounted in a gearset that is ready to run at Daytona. Installation of the pump requires some machining to the rear housing.
Gears are designed to move oil to the cooler at a rate of 4.5 gallons per minute at a 9,000-rpm speed. This rate permits improved oil-cooling characteristics.
The pump is driven directly from the pinion. The hex shaft seen here is mated to a machined hex port in the pinion.
This view shows the caged needle bearings the gears ride on. For strength and durability, the bearings are rated for 30,000 rpm.