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View Full Version : Finding a location for a thru hull scoop



pmann
06-23-2006, 03:47 AM
Can anyone tell me if I install a thru hull scoop for a ballast, on the same side as my engine scoop pickup, will it limit the amount of water available for the engine scoop? I would be installing it directly across from my paddlewheel, or about 4 feet in front of the engine thru hull scoop. I know that water flow could be altered by the one scoop in front of the other. Or, due to their distance apart, will there be no water flow loss to the engine pick up. I do not want overheating problems. Or does anyone have any suggestions on where to install the ballast pickup?

zabooda
06-23-2006, 10:39 AM
Why couldn't one tee off from the engine scoop and eliminate another penetration?

Smrtz
06-23-2006, 11:59 AM
couldnt diverting the flow of that water affect the rate at which the water cools the engine and cause complications if you tee off??

Could be way out in left here?

Buttafewcoe
06-23-2006, 12:34 PM
Tee off and an inline valve? On when ye want?

zabooda
06-23-2006, 03:50 PM
I don't believe so. One would have to do the calulations which I didn't do. If your flow rate isn't sufficent then you would need to put a larger scoop to account for both systems. The flow to the engine is controlled by the raw water pump and actually works as a restrictor at higher speeds due to the higher hydrostatic pressure and the pump is only utilized at lower speeds where the speed of the boat is not enough to force the water into the engine. There are two critical issues to evaluate: 1) At low speeds is the water inlet and the hose prior to the "T" large enough to pump water to the engine and the ballast at the same time. Normally the intake and the hose to the pump is overdesigned (larger) than what is needed and that "may" be OK (calculate it), 2) At high speeds there is plenty of water flow but by adding more tubing and connections you introduce system failure(s) such as hose and connection failures that that could restrict water to the engine and that would have to be a complete seperation somewhere from the intake to the engine. One needs to considering these risks with the risks of adding another penetration below the water. My two pesos.