hydrofoils are coming along

[Jeff Walkowiak]

Re: hydrofoils are coming along

here is a few picks of where I finally set the foils etc.

the last one showes one of the rollers I use between the skids

 

[rickdb1boat]

Re: hydrofoils are coming along

Jeff, I wonder if performance would improve if you removed the hydrofoil that's mounted on the outboards lower unit. They tend to force a boats bow down rather than lifting it. Just a thought. And what you have now looks good and I'm betting you see some positive results. Look forward to more test info..

 

[SoulWinner]

Re: hydrofoils are coming along

I was wondering how the hydrofoil on the motors A/C plate would affect the general handling of the boat in conjunction with the foils you installed along the tubes. How did the hydrofoil on the motor effect the boat? Would it be profitable to test your foils with the one removed from the A/C plate? Do they work together or is it possible that the foil on the motor counteracts the ones you just built to some degree?

 

[Jeff Walkowiak]

Re: hydrofoils are coming along

I just made the engine foils and haven't even tried them out yet,, so I don't know if they are a help or a hindrance,, my plan was to do exactly what you said it would do,, push the bow down theoretically lifting up the rear,, because of the way I did the front foils, the bow stays quite stable and I love the way the boat rides and handles even when cutting diagonally across wakes. previously the boat would spray water pretty badly and get everyone in the boat wet if I hit a wake with the boat diagonally, and since I removed the backs from the front seats,, the water would soak you , the seat backs blocked some of it .
With the foils the boat is a blast to drive even if it isn't a speed boat lol.
I actually see the hull lean in a fast turn and it tracks perfectly. I probably went a bit on the conservative side when I re did the thing as I could have gone down a few more inches, but it was so time consuming I just didn't want to have to mess with it again.
If I were to do this again I would make the foils 12 inches wide rather than 8 inches and I would place them at 12 inches below the joists rather that 8 in the rear and 9 in the front.
What I did notice , was far less turbulence in the back of the boat, and I may weld an extension to the rear foils about 4 inches , as that would also add a bit more lift to the rear without a lot of labor involved.
My belief was that all the water being corralled in the back between the engine bucket and the pontoons was creating a lot of drag. So seeing less turbulence there means there is less drag . So a little more lift in the rear would make it even better.
My wake now has 3 distinct rooster tails , 1 from the engine and 2 from the foils.

 

[SoulWinner]

Re: hydrofoils are coming along

My wake now has 3 distinct rooster tails , 1 from the engine and 2 from the foils.

I noticed that my 'toon seems to squeeze a LOT of water between the 'toon logs and the engine tray; clearly the constriction of flow there has deleterious effect on the efficiency of the boat moving through the water. Now I realize that it's a pontoon boat, not a planing hull, but it seems to me that there should be a way to clean up the way water moves through that part of the boat.

 

[Jeff Walkowiak]

Re: hydrofoils are coming along

that was my reason for making the first set even with the bottom of the engine tray,, I just didn't have the power to get that amount of boat up out of the water.

 

[Rancherlee]

Re: hydrofoils are coming along

Hate to bring this one back from the dead but I have a question. What did the Hydrofoils do your your engine trim range? I have an old 20' pontoon with the maximum HP (70hp) heavy 4 stroke on the back. I can only run WOT with the engine trimmed in ALL the way which really pushes the nose down and limits my speed to ~20-21mph with 3 people on board, As soon as I start to trim out I pick up speed but any little wave causes cavitation. I've been looking at ways to fix this but really like your idea as it looks like it will force the water to stay down around the prop where it is suppose to be instead of up between the motor pod and the pontoons.