P365 W40 Cooling Hull Ftg

[John Childs]

I have searched for this topic without an answer. The vents for the strainer hull fitting on my boat is facing aft. Most boats I have seen have them facing forward. The boat has been on the hard since before I bought her (Hull #80) and the previous owner didn't have a clue. I am assuming the engine ran fine in that configuration but cannot obtain previous owners advice. Was there a reason for the vent to be facing aft or should I correct it to face forward? In actuality, i have two strainer hull fittings facing aft. I am just trying to sort out the thru-hulls on the boat.     

[Dale Tanski]

John,
You are correct in questioning the orientation of the thru hull strainer.  They are designed to be placed so that the vent grate slots face forward.  They are typically shaped in a ramp shape so that debris (or a dead head) rides up and over the ramp.  The ramp shape also acts as a "ram" and as hull speed increases, the ramp with the closed back cup shape forces water into the inlet.  In the reverse orientation it might actually act as a venturi syphon and create negative water pressure as hull speed increases reducing water flow to the inlet.



Dale