Gerotor and spur-gear
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Le Mans Master
Joined: Apr 2006
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Gerotor and spur-gear
The gerotor pump has 4 lobes on the drive which takes roughly 180 degrees of crankshaft rotation to fill the chamber. The spur- gear pump for the Y has a 14 tooth configuration which has only 51 degrees to accomplish the same thing. Because the gerotor pump has roughly 3 1/2 times the work time to fill the chamber, the oil is allowed to ramp much more smoothly into the pump chamber and likewise shut off much more slowly as the cycle is completed. This smoother action is less likely to pull gas or air out of the entering fluid stream then the same volume rate spur- gear pump which is trying fill itself 3 1/2 times faster. At 6000 rpms, the spur- gear pump is trying to fill itself 42,000 times per minute while the gerotor is trying to fill itself at 12,000 times per minute. Because the gerotor pump is filling itself in fewer cycles or pumping actions, less heat is being generated into the oil hence a cooler oil temperature is being transmitted to the bearings. This results in potentially less oil degradation using the same oil change intervals.
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Thread Starter
Le Mans Master
Joined: Apr 2006
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The reason the new LS engine with its complete redesign has a gerotor pump and ford has always used them dating back to there Y- block. I copied this off a Y- block forum when I noticed it. 12 to 15 thousand dollar builds on engines no one seems to be willing to spend more then say $75.00 on an oil pump the titan gerotor pump is more then $400.00. It can be argued the old spur-gear pump works but then 6 volt starters cranked over cars that were low in compression ratio and still got you down the road to where you were going, lol.
Last edited by Little Mouse; Dec 12, 2019 at 11:45 AM.
Thread Starter
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
In motorcycles most are wet sump simpler and cheaper to manufacture and the bad part the engine and trans case are using the same oil. The gears meshing together cause gear shear that breaks down the oil anyone that has motorcycle like this should change there oil very early for longest engine life. oil pump spur-gears are not intermeshing to drive something hard but they still heat the oil more then a g- rotor pump.
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