dumas miller american hydro

hi all i aquired this boat from a friend for free and it is id say about 80 percent finished. the hull is built and from what i can tell alot fot he wood has been upgraded to acft plywood. i have a couple different engines to play with which include a homlight, and a zenoah g26 air. i would like to shoehorn wither of thies engines into this boat and not break the bank. i would prefer to use the zenoah if possible. my gole for this boat since it is my first, is to finish the boat and have somthing that i can run at the lake when i want to.

i just measured and the engine bay is 4.5 inches wide and 7.5 inches long

as far as running gear goes i am an open book i have no idea what i am doing here. i have been flying rc airplanes for 10 years and have flown multiple gas planes up to 100cc gas so i am formilliar with gas rc engines. the boat does not have any thing installed in it so i have lots of flexibility for the driveshaft and dive unit.

so if anyone can help me get this boat in the water it would be great. thanks for the help i will post some pics soon.

A friend of mine converted the Circus Circus to a gas runner with success. He used a standard 1 1/8 Speedmaster rudder, (go dual pickup if you can) and a 1/4 round bottom hydro strut (not extended). He used a Dick Tyndal (Virgina Craftsman) turn fin. He runs a stock Zen 26 with a 90 deg header and tuned pipe. He used a 8 or 10 oz tank converted for gas, but I'm sure a bag would work as well. You can use a standard zenoah mount, you may have to get smaller iso rubbers (see the McMaster/Carr part number in the Warpath instructions). He did not move the motor, its mounted as far forward in the engine compartment as it will allow. The starter is almost against the cowl. His prop has been a Prather 265 or 270 on a 1/4 shaft. he did have to cut the bottom out to get the mounts in, and then re-epoxy the windows he created back in. It runs strong like this, its light. It will carry the right sponson down the straight, and require a little left input to go straight as well. I wouldnt put anything modified in it, You'll spend more time rowing out to get it than running it. If you want to see how it runs, check my review of the Hitech Sport Hydro, the second boat is this one.

thank you for the kind words. i tried this on another forum and got nothing but flak from the old farts saying it cant be done.

currently the zen is an aircraft engine modded to electronic ignition. i assume i will need to remove the aircraft hub and convert back to mag igtition and add the pull start. i was also thinking about cutting down the cooling fins and putting a waterjacket on the engine. that is the only modds i was planning.

got a few questions

do i need a clutch?
surface drive our subsurface?
radio box?

You wont have room for a clutch, with a hydro, the strut is mounted on the transom, and it hangs below the hull. Even though it hangs like this, its still like a surface drive - only one blade of the prop will be in the water at any time. The radio box is built into the hull (middle compartment). You will need to go water cooled, there wont be enough air flow to cool it, and you will have to go back to the Mag and pull start.

ok cool do you know of any threads about conveting this engine?

here are a couple pics of the boat so is the radio compartment right behind the engine bay or is it under the panel behind the cowl bay? i will be buying the instrunctions and plans from dumas soon so this will probobly clear it all up though

The design is slightly different, I think he actually put it in the larger open area, and designed his own box that is larger.

Hey Rotccapt!

Just wondering: Is it a boat or is it the wooden version of Starship Enterprise? :ohmy:
No honestly. It's a beautiful and very different piece of work.
We don't allways have to look like the rest - huh?
I wish you luck in finishing the "Starship", so please send some updates as you come along.

Cheers!

Woody.

well guys i got the boat home and set the zenoah in the hull and i think it will work i will have to make some mods to the cowl to accept the carb and exhaust but it should fit. only thing that will stick out the top is the spark plug and cap. one problem though i will have to go with a pulley and belt because there is no room for a pull start unless i mod the cowl a bit

This old fart goes to other web sits too. When your done we can race. Hope this helps