|Oil Pump Function in Chevy 350 Engines|
When the engine rotates at approximately 3,000 rpm there is bound to be frantic and violent movement of the pistons inside the engine. At the same time the crankshaft is spinning swiftly. Even the rocker arms are rapidly moving in two-steps with each respective valve. No matter whether the Chevy 350 engine is just sitting idle in the drive or rapidly moving at full-throttle, what it requires is a good lubrication system.
Oil needs to be directed to all of the metal contacting surfaces. This is possible through a full-pressure lubrication system comprised of an oil pan, an oil pump, several quarts of oil, and a series of passages inside the engine. An oil reservoir is to be found directly below the crankshaft with internal passages within the cylinder block, crankshaft, and openings in the cylinder heads. A 1/2 inch and 5/8 inch diameter oil pump inlet on small-block and big-block engines respectively, with an adequate suction screen submerged in engine oil, provides free-flowing oil to the pump. The pump is driven by the camshaft. The oil supplied to the pump makes its way through a full-flow oil filter into a 1/2 inch main gallery on a small block. The main gallery is positioned above the camshaft. The lube travels from there through a hole to the groove situated nearby the rear side of the rear cam bearing. This is the position where the lifters and rear main are oiled. The four front cam bearings have grooves that pass to each individual main bearing. Oil passes down into the crankshafts main journals through tiny holes in the upper main bearings. From the main journals it travels to the rod journals.
At the time the above action is taking place, the crankshaft is continuously spinning. And each rod connected throws oil onto the respective cylinders. This is not only to lube the moving pistons and rings but also to help seal combustion. Oil travels from top of the engine down to the springs and valve stems. And there it helps in lubing the valve stems as they budge about in the valve guides. A relief valve is responsible for circulating the oil back to the inlet side of the pump. This helps to keep the pressure from getting too high at the oil pump. At even higher engine speeds, the moving oil might whip the crankshaft and cost power. This is called as windage. To minimize windage, install a windage tray to turn the oil away from the spinning crankshaft.
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