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chris_seven chris_seven is offline
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Join Date: Feb 2004
Location: UK
Posts: 2,231
Originally Posted by boosted79 View Post
You are assuming the stock pump gets a 100% "fill" of the volume between the gear teeth. If it does not, and porting the intake of the pump increases the "fill" then it will pump more oil. Same as porting a head increases the VE and the air the engine will pump.
Does this mean that at high rpm that a 911 pump will cavitate as this is the inevitable consequence of a restricted inlet port when considering gear pumps.

If you don't fill the pump due to a restriction then the pressure in the cavity will fall and ultimately the oil will start to evaporate and this will damage bearings very quickly.

The restriction to flow will also be engine speed dependent so high revving engines will be more significantly affected.

If you consider a typical gear pump with a delivery of around 100 l/min the inlet port size would typically be around SAE-12

if the inlet size were -16 then the pump size would be closer to 180 l/min delivery.

Last edited by chris_seven; 09-30-2017 at 07:20 AM..
Old 09-30-2017, 07:17 AM
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