motor questions for newbie

[dirtbag]

just a bit of info on my mini most project you can find the plans for free on the internet www.muskokaseaflea.ca,mine has a wider cockpit than the plans it can fit 2 people I am 200lb and I take friends my size regularly (400lb) I bought a old 18hp for $250 which pushes 2 people about 30mph,the boat took me about 20 hours to build

[X-1hydro]

as much as that sounds cheap and good. its not fast enough for me id just get bored with it then not use it and it would have been a waste of time. plus i want somethin big

[Mark75H]

better plans on eBay

Your X-1 is on there as #11

The guy is a pirate that has downloaded free plans off the internet and burned them onto a CD, but the Aquarod and Aquaracer should be what you have in mind; well able to support a standard motor

[Mark75H]

I think John Schubert (TART) was involved with the Aquaracer, it was intended to be a J (99ci) racer, it is more than big enough.

[X-1hydro]

so would a tunnel hull be possibly faster and more stable? and would it cost about the same to build? my dad is a truckdriver for a lumber company(lumber products)so i can get marine grade wood for considerably cheaper. any help on the subject would be great. i just want somethin fast, stable, safe, fun and atleast over 12 feet long. thank youo on the

oh and if anyone could find any info on the aqua racer and aqua rod for me to look at i would be very thankful. i think i'll switch over and build one of those.

[X-1hydro]

well i think i found a 2 cylinder 40 horse for free so im gonna build the x-1 and try thr 70 on it but if its to heay ill just throw the 40 on. and then if i need to ill build a tunnel hull. is there any way to make the back of the x-1 more bouyant if need be?

[Mark75H]

Wider at the back, higher all across the back ... just like a tunnel hull

[X-1hydro]

would it be safe to modify the plans to widen the rear?

[X-1hydro]

ok on the plans the boat is only 17 inches high in the back so when i enlarge it top to bottom would i enlarge just the back or would i increase the height for all 5 of the frames? and how high do you think it would need to be to float my 70 horse?

[Winger Ed.]

Whew,,,, I finally made it!

OK, let me address a couple things I've learned from the two hydros I built.

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Turn fin:
Keep it. Maybe even put air traps running off it too. The air traps will help trap more air under the boat, lifting it a bit more out of the water at speed, and help stabilize it in turns. A hydro doesn't turn like a regular boat hull does. A boat turns like a motorcycle on dirt-- it sort of slides around the turn as you change directions, and leans downward in the direction of the turn. A hydro wants to lean out towards the outboard edge of the turn- like a car. When it does, you have to help hold it on the water and not let it 'slide' or the allow the outboard edge of the sponson dip down enough to go under the water... if you 'dip' a sponson, it can very easily, or more nearly, will probably-- flip over. And it will happen in about a millionth of a second too. Even if you're not building a racing boat- it ain't a toy either. These things are like pilots say about the old, and slow Piper Cub airplanes, 'They just barely go fast enough to kill you'.

Plans:

For my first hydro, I built the 'Ben-Hur' from plans I got from the Clark Craft company. They are on the net, search for 'Clark Craft' or it will turn up while looking for 'boat plans' too. I switched it over from a wooden boat to all Aluminum, and built it to plan and raised the cockpit sides to handle me and the heavier engine ( 4 cylinder Merc 50 horse). It was OK. But it was still a 50 horse on a 12 footer......

For Poco Loco, I got the plans off the free 'boat plans' site. You have to enlarge them yourself, but they are free and they also have the plans for the hydro you posted with your engine picture. The 2nd hydro is Alum. too. I took the plans for the 'Airmarine Special' hydro- a 12 ft. 'D', and enlarged them.

I raised the top of the airfoils a inch, widened it 12 inches in the tunnel, moved all the 'ribs' to 14 inches apart, and added one more. That made it 16' long instead of 12', added a real chair & instruments, and raised the cockpit sides several inches to handle it setting deeper in the water with a stock 150 hp Merc. V-6.

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Changing the dimensions on a boat can be done, just be careful to keep it all sturdy and safe. You will probably change the center of graivty in the process, but that is workable if you can move things around to compensate- like the fuel tanks or drivers station.

Something I sort of wanted to do, but didn't, was to make my 16 footer with 'wet sponsons'. The sponsons have a huge hole at the bottom of thier back ends to let the water out as you take off, but at rest, the boat sits more level in the water as they 'flood down'. If you have a center of gravity that is real far back---some say wet sponsons help it plane out faster by being front heavy on start off, then losing the weight as you come up & get going. Once you get moving, they drain in a few seconds, and forward motion keeps the water out the same way the water pulls away from the transom at speed in a normal boat.

Some sites you might want to check out:
I don't have the url, but they are easy to find on a search-

"Clark Craft". They have plans and the hardware you'll need like steering kits, turn fins, various epoxys & such.

"US Composites", they have all manner of epoxys and a decent price on the 2 pound per sq. inch foam you'll want.

"Boat Plans" They have dozens of free plan sheets on all manner of old boats.

'Antique Hydroplanes' Its a site where folks post pictures of old 1930's & 40's era hydros being restored, famous racing hydros, the evolution of hydros from the 'Rum Runnings' days to the present-- all sorts of stuff like that.

Good luck with your project, and keep us posted.

Ed.