V8 Hydroplane design.

[rebar]

Iv been thinking what it would take to build a 18' inboard hydroplane powered by a V8 to blast up and down the river in.

Anyone who has ever tried to obtain race proven plans for a inboard hydroplane knows how protected they are. So my only choice is to go with clark craft plans. Iv read a post over at vintagehydroplanes.com where a credible builder IMO said the clark craft plans are flawed. Sponsons arnt deep enough and construction not strong enough. Interesting read..

http://www.network54.com/Forum/61035...iler+-+%241000

Has anyone around this forum built a wooden inboard hydro?

[messabout]

Do you have a good grip on the reality and magnitude of such a project? It will cost a plenty. You might get into thousands of dollars worth of props before you find the right one and that is just props. YOUR V8 will need to be marineized which means changing a lot of things on your SBC or whichever engine you choose. You will even change stuff on the interior of the engine, like rods, cams, etc. This is a big project.

Why not think of something simple and god awful fast ....say something on the order of the Crackerbox. It uses a V8. That design has been around for ages and is well proven, has a following that would be pleased to give you all the information and advice that you'd need and much cheaper to build too. If you want to blow off most of the deep vees, the little Crackerbox will do it. It will also give you a sore neck as these boats are dragsters.

If all you want to do is go fast then check out the GT type outboards. They cost a lot but they're mind boggling fast. Faster than the V8 that you might build. That class uses a LeMans style start. That is from a stationary position. When the gun goes off the driver punches the throttle and the boat absolutely leaps out of the water. Want to learn more about that kind of hydro contact the APBA. (American Power Boat Association)

There is a gentleman who sometimes posts on this forum. His name is Jim. He is the leading authority on this subject and maybe he will pick up on this thread. He has all sorts of printed matter that the aspiring speed freak can use to advantage.

[kach22i]

Go for it, but remember............ Speed = Danger

Might be better off with a hovercraft, then you can use it when the river freezes too.

How big of a river?

Any hp or noise restrictions?

Lots of smaller rivers in my area have a 5 hp power limit to protect the banks.

Is this river known to have any logs floating in it?

[Rampager]

Good god he asked about a hydroplane not building the space shuttle!

This board is amazing at how negative it can be. If he wants a hydroplane let him build one, its not going to be several orders of magnitude more expensive to build that than any other type of hull the same length.

also FYI I can attest first hand that a bone stock GM zz4 survives extremely well in edurance boat racing so its not necessarily tru the engine will require a "ton of internal" modifications.

Find plans and build your boat, have fun.......

[rebar]

Thanks guys. Yes I know its a big project. I wouldn't even think about trying it if I didn't see this car engine powered full size boat built from model plans..

http://www.fusionhydros.com/

Now I will admit, you wouldn't catch me in that boat. But there has to be some middle ground between a $20k racer and a budget build like the fusion hydro.

No noise or speed restrictions in the waters around here.

Can anyone recommend boat design software which will give bulkhead shapes?

[kach22i]

Originally Posted by rebar

http://www.fusionhydros.com/

Cool link, can't answer your question though.

[rebar]

http://www.vintagehydroplanes.com/la...tery_2008.html

[messabout]

Rampager, I am not being a naysayer here. Rebar wants to have a hydro to go fast up and down the river. Hydros are basicly racing boats and they are normally quite sophisticated pieces of work, not to ignore the problems that fast boats have with river traffic, wakes, floating debris, etc. Let us presume that the 18 footer is to approach 100 MPH. A stock engine is not likely to produce the power needed for such an ambitious speed. The engine shown in the blog will have cost way into the mid 5 figures. If Rebar has that kind of money to spend on toys, then god bless his good fortune and he should by all means have a bad assed hydro.

[Obsession]

If you're looking to impress others, a problem with race boats is that the bar has been raised and raised over time. It must have been fun 50 years ago when you could build a raceboat in your garage with common materials. I would have enjoyed living in an era where more people were building their own boats with their own hands.

But cant you still have the same fun with the same boat that produced that fun in the 1970s? Is the goal to impress others or to enjoy the boat yourself? Even if it only has a stock engine and isn't the fastest on the planet it's still going to be a blast (even if not the most practical boat either.)

[Rampager]

Originally Posted by messabout

Rampager, I am not being a naysayer here. Rebar wants to have a hydro to go fast up and down the river. Hydros are basicly racing boats and they are normally quite sophisticated pieces of work, not to ignore the problems that fast boats have with river traffic, wakes, floating debris, etc. Let us presume that the 18 footer is to approach 100 MPH. A stock engine is not likely to produce the power needed for such an ambitious speed. The engine shown in the blog will have cost way into the mid 5 figures. If Rebar has that kind of money to spend on toys, then god bless his good fortune and he should by all means have a bad assed hydro.

When I see a jetdriven boat with a stock GM ZZ4 do over 90 mph, this feat should be relatively easy with an air packing lightweight race style prop boat.

Ive built wooden boats before and had my share of people tell me "it cant be done" blah blah blah If they were doing it 20-30-40+ years ago its a doable project especially considering you have all that expereince to draw from. Not to mention modern materials AND very importantly the internet. That hydro page posted has a ton of cool projects on it and I bet that site alone would reap you a dozen people willing to bend over backwards to direct and assist in such a project. That is if I know wooden boat building people like think I do....



Sounds like a great project to me. Both my wooden boats were extremely rewarding and I bet I met more people building and using them than with any other hobby Ive ever had. Just do it!

[tunnels]

Originally Posted by rebar

http://www.vintagehydroplanes.com/la...tery_2008.html

Wow what a fantastic site !!!!

[Boston]

I say go for it
its often the journey and not just the destination that makes the adventure
have a great time and enjoy it

cheers
and best of luck
B

[nautique210]

Take a look at the build pics here. What a masterpiece

http://www.misswahoo.com

[rebar]

I need to clarify.. I dont want to impress people other than maybe inspire them to build a budget hydro. I dont need to run 100.

Problem is.. I cant find any plans. And basic questions Iv asked about sponson aoa design on the vintagehydro site go unanswered.


http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

[Boston]

I ran across some plans a while ago
when I get a chance Ill try and dig them up for you
not sure if they are going to be what you want to build but it was for vintage hydroplane