Know Your Oiling System

Oil pans with kick-outs are designed to trap flying oil before it can drown the rotating assembly. This Moroso race piece features special plugs that must be removed before the pan can be removed.

Oil pans with kick-outs are designed to trap flying oil before it can drown the rotating a

Oil Control
While too little oil can cause catastrophic engine failure, too much can hurt the engine's performance. Windage occurs as the crankshaft rotates through the oil in the pan. This creates a chaotic amount of splash that can coat the rotating assembly with excessive oil, costing horsepower. To combat this problem, oil-pan manufacturers, such as Milodon, Moroso, Canton, and Hamburger's, have come out with crankshaft scrapers and windage trays.

A crankshaft scraper is usually built into the oil pan or attached to the oil-pan rail. Often mistaken for a baffle, a crankshaft scraper is a ridged piece of metal located near the crankshaft counterweights. The scraper does not actually touch the counterweights but hovers next to them, directing flying oil to a kick-out in the pan. Below the crank scraper, a windage tray is often bolted in place below the main caps. This is a piece of prebent, rigid metal with holes that's meant to separate flying crank-case oil from the calm oil in the pan. Some racers employ both a scraper and a windage tray, while others use only one or none at all. However, before you ditch the idea of using a windage device, we can assure you there is test-proven data showing considerable gains through proper oil control.

PickUps
We've all heard the stories about oil-pump pickup tubes falling off the oil-pump body, which causes engine failure. While this is not a common problem, it does occur. All the high-performance oil-pan companies have accounted for this situation and have taken precautions to make sure their pickups stay in place. Milodon uses a 4130 chromoly press-fit sleeve in its small-block pickup bodies. The pickup tube is pressed 0.015 inch down into the sleeve and then bolted down by an independent strap to make sure the tube is held in place.

This Milodon oil pump and pickup are outfitted with a bracket hold-down and screen spacebar. These features make sure the pickup tube stays in place while the screen sits a perfect distance off the bottom of the oil pan.

This Milodon oil pump and pickup are outfitted with a bracket hold-down and screen spaceba

Before the oil-pump pickup manufacturers began addressing this potential problem, many racers often placed a small spot-weld between the pickup tube and the pump body. While this does work, most of today's manufacturers are against this practice, as welding temperatures may stress the pump body, affect the internal gear clearance, or weaken the pickup tube and/or bypass spring. Before doing any welding, contact the oil-pump manufacturer.

DeburRing and Clearancing
Oil-pump modification can be beneficial or detrimental, depending on the method by which it is done. Many of the oil-pump manufacturers recommended leaving their pumps alone, as they are manufactured with quality built into them. However, if a stock pump is in the works, there are a few things that can be done.

First off, cleanliness is key. Make sure every piece of the pump is reassembled clean. As for the actual improvement process, the biggest gains can be had by deburring the pump body's flow path from the internal gears to the pickup. Some engine builders like to deburr sharp edges on the oil-pump gears to reduce wear, but this is questionable, as setting the gears back up requires precise measurement. If at all possible, do not alter the pump gears, as they are set up a predetermined distance apart to ensure an adequate amount of oil is pumped with relation to engine speed.

Virtually all oil pumps operate by squeezing oil through a small passage. To regulate the amount of pressure, most pumps use a pressure regulator that consists of a valve regulated by spring pressure. When the pump exceeds the rated spring pressure, the spring compresses, allowing the valve to relieve the pressure. Engine oil pressure can be increased with a stiffer spring or by shimming to increase the seat pressure. The standard rule of thumb of 10 psi per 1,000 rpm of engine speed is a good place to start. However, with a properly designed high-performance lubrication system and quality synthetic oil, lower oil pressure levels of 45-50 psi for an engine speed of 6,000 rpm is acceptable.

By Scott Crouse

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