ABOUT THE OIL PUMP: The oil pump's job is to deliver lubrication throughout the engine, and it's operation is critical to the engine's operation and longevity. Due to it's internal design, it is also one of the most misunderstood components inside most engines. Critical clearances are required for minimum leak-by of the pump gears and smooth surfaces are required for minimal heat production while under load. Due to manufacturing processes, the very critical tolerances and optimum surface smoothness can not be attained on a mass production basis. Additionally, wear on a used pump and worsen these critical points aforementioned, however, since you would have to do the same general work to Blueprint a new pump, starting with a used pump and decent condition may even bee better since it is already "broken in.
HOW TO MAKE IT BETTER: By tightening up the critical clearances of the pump gears you can achieve a more stable oil pressure level as when the oil heats up, increase the flow and pressures without having to go to a larger, harder to turn pump. By polishing the contact surfaces you can relieve strain on the oil pump drive shaft, distributor gear and timing chain as well as significantly reducing heat production by the means of less friction inside the pump. All this can be achieved in just an hour or two with basic tools and equipment found in most home workshops.
THE PROBLEM: The typical hi performance automotive oil pump does not run on bearings or bushings, but rather it is relatively rough metal on metal surfaces. Faster it the engine spins, the faster the oil pump spins and creates more heat within the pump which is directly transferred to the already hot engine oil thus potentially significantly accelerating the oil temperatures.
DIAGNOSING THE PROBLEM: Higher volume pumps do not necessarily place more load on the distributor gear , because the oil pump creates the same pressures before the bypass valve opens, and pressure is the measurement of how much load the pump sees. Moving more oil at a lower pressure is easier to do than moving less oil at a higher pressure. However, the increased surface area and the friction resulting from the extra surface area in the high volume pump can produce more load. These situations can be easily visualized by reading the oil temp as soon as it leaves the block through an external oil filter in comparison to the temp in the oil pan just before it leaves into the pump. As the oil is drawn up through the pump, the difference in oil temperature created by the pump can be significantly higher depending on the RPM, which creates the friction and heat.
SELECTING YOU PUMP: If you wish to modify your oil pump as outlined in this procedure, for these purposes a used oil pump are many times more desirable to use for this build up than a new one since the rotor to rotor clearances are now perfectly worn in, however, the rotor height is usually excessive due to generous manufacturing tolerances and needs to be "set", or "clearanced" for maximum efficiency. Smoothing and polishing the contact surfaces will reduce friction, reduce oil temperatures and increase flow and pressures without the need for a higher volume pump..