Cavitation plate height on a 1957 35 Seahorse.

[rolmops]

Hello.<br />I am fooling around with the transom height on my boat.Normally I would try to have the cavitation plate flush with the bottom of my boat.<br />In this case, it is a flat bottom boat and these engines have this elongated water inlet just above the cavitation plate.<br />I am afraid that,if I set the plate flush with the flat bottom, this water inlet will become an air inlet.<br />Did anybody out there have to deal with this problem? What was the proper safe height to set the engine at?<br />Thanks for all your advice and help.<br />Cornelis.

 

[OBJ]

Re: Cavitation plate height on a 1957 35 Seahorse.

Hey rolmops, check the hangy down thing on the bottom of the anti-vent plate. Should be a water intake screen there. If so, no problemo. Put her flush.

 

[rolmops]

Re: Cavitation plate height on a 1957 35 Seahorse.

Thanks outboard Jim.<br />The problem is that the lower water intake is connected to the one above the cavitation plate and the water passes by the one above the plate on its way to the impeller.

 

[OBJ]

Re: Cavitation plate height on a 1957 35 Seahorse.

Don't think that should cause a problem. Should go right into the pump. Worked for me anyways. Some will be lost through the holes but the bulk of the water will end up in the pump.

 

[Boatist]

Re: Cavitation plate height on a 1957 35 Seahorse.

Rolmops<br />The holes above the cavitation plate are water output holes not input. The Input is below the cavitation plate where the screen is.

 

[dick]

Re: Cavitation plate height on a 1957 35 Seahorse.

Anti-ventilation plate, there is no such thing as a cavitation plate

 

[Paul Moir]

Re: Cavitation plate height on a 1957 35 Seahorse.

I too would like to hear the answer to this question - I was about to ask it myself. I belive what rolmops is refering to is the plate that covers the passage from the water inlet on the back of the lu to the water pump on the front. The plate extends about 1" above the anti-ventilation plate and has a few holes drilled in it. The pump base is about 4-1/2" above the AV-plate. I *think* the holes must be to releave pressure on the inlet side of the pump when water is being rammed into the intake from the prop. In neutral, the holes would definitly let air into the water pump if it wasn't submerged. Any insights out there? Thanks!

 

[rolmops]

Re: Cavitation plate height on a 1957 35 Seahorse.

Thanks Paul, for making my question clearer.<br />That is what I was aiming at.

 

[alcan]

Re: Cavitation plate height on a 1957 35 Seahorse.

This cover is called the water by-pass cover. When the boat is not on plane this portion is submerged. When the boat is planing there is more than enough water to cool. The holes in the plate are to drain off water when not in use.<br /> Rollmops set up your motor even with the bottom of the boat.

 

[Chinewalker]

Re: Cavitation plate height on a 1957 35 Seahorse.

Hi Rolmops,<br /> I've got a '56 Johnson 30hp (same cooling system) that we've got hot-rodded up a bit. We run it on an old Utility Racer and have it jacked up to 19" (38 mph on a good day!). The cavitation plate is two inches ABOVE the bottom of the boat and it pumps water like a great dane marking territory. The prop throws plenty of water into the intake screen - if you're running flat on the bottom you'll have no problems...<br />- Scott

 

[Paul Moir]

Re: Cavitation plate height on a 1957 35 Seahorse.

Thanks a million! I needed to know if i could build my boat transom a couple inches higher than 15, now I know.

 

[rolmops]

Re: Cavitation plate height on a 1957 35 Seahorse.

Hello guys.<br />Thank you all very much for your input.<br />It shall go flush with the bottom.<br />Maybe I'll run her from Rochester to the Thousand Islands to race you Chinewalker!

 

[CWiggle1]

Re: Cavitation plate height on a 1957 35 Seahorse.

I've been messing with a '62 40hp (RD-24L) and can't get the water pump to pick up. Any idea where I can get a new impeller and/or housing?<br />I always thought those little holes were for water intake...