Thread:

Fun speed boat w/v drive

Originally Posted by love2flymn

Awesome..We'll have to keep in contact then to compare findings.
I am thinking now that the best option would be for me to do a direct drive... I also thought about just buying a trashed jet ski and mount all the necessary parts in the bottom of the boat but IMO jet drives are way too energy inefficient (you spend way more $$$ on gas than is necessary)

I was thinking about finding a wrecked tubocharged wave runner and mounting all the hardware onto the boat. I don't think I could live with having a jet on my boat though

I believe it all comes down to which type of hull you obtain (And how much money you are going to spend)

Even though it is a little project, you will still be spending a ton of money for the rigging if you go with a v-drive or direct drive. Thats why it would be cheaper to find a jet ski and swap the hardware to a boat.

Pulling ??
,,

Originally Posted by love2flymn

I'll be designing and building the hull myself too. I really like the hydro/pickle fork look so that's what I want to go with.
I know with radio controlled boating a surface prop is much better than submerged drive. What about in the big boat world? Is it best to just stick with submerged?

Ellison hulls (picke forks) were designed from the little RC boats. They are now the fastest hull in drag boat racing. The sponsons are removable and depending on motor placement and angle of your vdrive, the sponsons can be shaved to fine tune how it rides or pushes thru the water. Now the outrigger style hull that I am speaking of that holds the current ET and MPH records has a w drive because it has two surface props.
I would like to see a 100 cubic inch motorcycle engine turn twins. Maybe a new avenue for s&s motors?

Crap never mind. I meant to ask what color are ya gonna paint it?

Oh...I plan on painting it red btw. I thought then I could call it "Red Rocket" but I'm not sure my wife would like that very much.. Also I don't think I would be doing a twin drive. How do I do the prop then? Keep the boat flat bottom in the back and ride the sponsons and tail of the boat or hang the prop down a bit and ride front sponsons and two rear sponsons.

My only other concern I came up with was that these hydros probably don't take on waves the best. Lots of big boats on the river so often times you'll come across 2-3 ft swells. I suppose if it's fast enough I could just drive around them. Or make the hull sturdy enough to jump them. But then if I'm going fast enough I could have a blow over. I guess I'll live and learn!

Originally Posted by love2flymn

Oh...I plan on painting it red btw. I thought then I could call it "Red Rocket" but I'm not sure my wife would like that very much..

If you want her thumbs up on the project let her name it.

Also I don't think I would be doing a twin drive.

Not many people can pull twins off so don't sweat it.

How do I do the prop then? Keep the boat flat bottom in the back and ride the sponsons and tail of the boat or hang the prop down a bit and ride front sponsons and two rear sponsons.

The only direct drive boat I have ever seen had some kinda odd angle on the prop shaft that made it extend a good 2 feet beyond the rudder. It was a shin biter.

My only other concern I came up with was that these hydros probably don't take on waves the best. Lots of big boats on the river so often times you'll come across 2-3 ft swells. I suppose if it's fast enough I could just drive around them. Or make the hull sturdy enough to jump them. But then if I'm going fast enough I could have a blow over. I guess I'll live and learn!

Most hydros sit pretty low in the water, especially the back end, but since your putting a much smaller motor in it, who knows how it will sit in the water. Good luck.

It's a torque deal. bike motors have a high hp to weight ratio at high rpm but very little torque on the bottom end. Try putting a little 110 hp in 3 gear from a stop and try to take off. Building something small with a prop would be more work than it's worth considering how simple/cheap it would be to wack up a jet ski drive system a graft it into any kind of hull you could find/build.
Think....prop/cooling system/exhaust.
Jet ski motor uses crank for centerline of drive, bike motor output is way offset if you use trans and you pretty much have to, there is no easy way to mount output shaft on the end of the end of the crank.
Closest thing that might work....Newer Honda gold wing motor.
Dead as simple 6 cylinder 100 hp @ 5k 100 lb. torque @ 4k out put shaft come straight out the back almost in the middle...Trans might be be usable with a prop.....just understand that boats with props only need 1 gear....