Classic Australian Wooden Power Boat Association

Hi all.
I have just joined the association and am building a GlenL Ski King which is up to fitting an engine. I will be installing a 302 windsor and need someones experience with water inlets. I have a bronze skeg which has a water inlet hole cast into the leading edge around 40x5mm flowing to a 3\8 npt thread on the base of the skeg. Will this be a large enough inlet for this engine?
Thanks
Peter.

Hi Peter, welcome! I'm no expert, but I run a 283 Chev in my boat, and use two water inlets through the hull. The surface area of each opening on them would be approximately 125 square mm. That times 2 equals 250 square mm (how's that for mathematical genius). Your opening provides 200 square mm, so it is a bit less than mine. Somebody else in the club may be running the skeg opening like yours and can offer better advice. I guess you would be close to having enough water flow, but you would have to try it and see. If it works for you, all well and good - you won't have the added drag (although minimal) caused by the extra water pick-ups. Cheers, Jon.

When I was fitting out race and ski boats I always used half inch id pipes and hoses to ensure plenty of water flow. If that proved to be too much then I would be able to restrict flow which is quite simple where increasing flow is a bit more complex

In addition to the above I always used 2 water pick ups and fed the water into a manifold in the boat to ensure there was still water flowing in the event a pick up had been compromised by a twig or whatever which often happened where we used to ski and race

Now Hookster, I'm sure I noticed a lot more than two water inlets into the inside of that hull.

Just remember the water flow rate will be whatever the smallest hole size is, a 5/8" will usually be as good as two 1/2", but like the man said, crap when it blocks.

Alan.

Aggressor has one half inch water pickup on the end of the rudder. The flow is that great that it has two water restrictors. More water is not always best as most ski boat engines run stone cold which is not good.
Two water pickups on a ski boat is common practise for the previuos mentioned reasons. Just make sure you have one way valves in the lines as sometimes the water goes in one pickup and drains out the other.

Thanks for the info I will attach this inlet to a second 1/2 inch through hull join the two at at the inlet side of a water strainer and then a run a 5/8 hose to the water pump. By the sound of it if nothing gets blocked, raw water cooled engines tend to run a bit cool in our chilly Victorian waters.

Very observant of you Alan and thanks again for bringing the woes of clinkerville back to everyone's attention. In addition to water flowing through the engine, I also like to cool the sump (and half way up the block) from the outside as an additional precaution against over-heating.