Raw Water Pump
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At speed does the raw water pump do anything?I am going to install relief valves and am trying to figure out if I should install them before or after the pump.It would be great to install them at the sea strainer which seems like they would work because the water is at pressure as soon as it enters the boat but does the pressure increase because of the pump at speed.Thanks
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At idle or threw the harbor its roughly 5 psi but when on plain 35 to 40 psi or more!I plan on installing relief at the strainer.Does this sound good?
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I think if installed before the pump you would have issues with the pump sucking air at lower speeds.I thought all reliefs were after the pump for that reason.
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merc. marine likes 30-35 lbs. max. your on the high side put your pressure relief in the strainer. The pump can't suck air the blow off valve it is set in the closed position and only opens when the set relief pressure is exceeded. good luck, J ps the idea here is to prevent excessive water press. which could blow intake manifold or head gaskets etc.
Last edited by 1CE; 02-08-2008 at 01:53 AM.
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Can the Merc raw water pump (at 5K plus rpm of the motor) exceed the 25-30 psi to the motor? If so, does the merc racing relief valve be better installed between the pump and the motor? That way the motor is completely protected from any spike in water pressure?