Newbie ESC Water Cooling Question

[JIM MARCUM]

Hi Jim,

When I increased the size of the rudder intake holes on my Genesis I started shearing the nylon safety screws with ease, and even with the brass screws that I am using now, they are getting quite deformed after about four x 15min runs. I am putting this down to the extra drag on the rudder due to the larger inlet holes - they are quite a lot larger. I can now see a very decent show of water squirting out the outlet on the side of the hull, even at moderate speeds (guessing about 20% of it's 60mph top speed). Now thinking I may have gone a bit far in increasing the size of the inlet holes.

I am going to be offsetting the rudder, and thinking about doing things a bit different. I certainly like the extra water flow that the increased size inlet holes give me, but when I offset the rudder this extra drag is going to make the boat veer more to one side. So I am thinking about filling in the rudder inlet holes and putting a hull mounted water inlet pick up on the other side to componsate for the normal rudder drag. Does this make sense?

One concern I have about a hull mounted water pick up on the Genesis, either under the bottom of the boat, or mounted on the transom, is will it pick up a consistent and reliable flow of water especially at high speed if the boat is barely skimming (flying) across the top of the water ? At least with a rudder pick up you can guarantee it is always under water.

Just thinking, on the Genesis the transom is mounted higher and fully out of the water. Maybe the pick up needs to be attached to the back of the sponson. Didn't you do a conversion from rudder inlet to separate twin water pick up on a Genesis? I seem to remember a posting from you a few months ago on this.

Jon

Jon, I'd use the H2O inlet(s) that come with your new offset rudder. If you need more cooling, just epoxy a 1/2" aluminum "L" on the sponsons, drill a hole in them to insert the brass tubing pickups, pass the brass thru the sponsons, and hookup silicone tubing to your ESC/motor. The brass pickups ends should be about 1/4" below the sponsons to assure adequate H2O flow at speed. JIM

[VedderHunter]

Thank you guys for all the great ideas. I have pretty much isolated the issue to the ESC. I tried the mouthful of water idea and found that water flowed freely from the rudder to the ESC input nipple and also from the ESC exit tube to the hole on the side of the boat. As mentioned above, there is a good possibility there is some excess sealant inside of the inlet or outlet of the ESC. I will try to remove the nipples tonight and see if any visable sealant can be found and removed.

On a side note, I did have the boat out last weekend for one run with a new balanced and sharpened X442 Octura Prop. Wow did that make a difference in speed over the stock prop. Only ran 2 min run as I did not want to over heat the motor or batteries.