rash_powder

I am looking to build my first airboat. Been lurking and reading off and on for years now, and finally getting to where I think I should do it. The boat is going to be about 20" x 40" with a flat bottom. I'm pretty sure I have all the details of the build worked out in my head, but I am not sure how big of an engine I will need. I am looking to use a 3 blade 16"x10 pusher propeller. First I am going to get the engine, mod what I need to on that and build the boat around the mounting needs of the engine. It just seems smarter/easier to go engine first. So, knowing I am looking to use the 16x10 pusher, would a 30.1cc Echo chainsaw engine be enough? I have found one locally for $50. The propeller is @ Tower hobbies, they only offer a 16" 3 blade. If 30.1cc isn't big enough, what size should I look for? Would getting a pipe for the engine help any or no? I know the tuned pipes help a lot on my Baja and make the race boat motors scream. Thanks!

Altered1

I would get your engine sorted, then by the sound of it, you are going to have to mod it for use with a prop. Get that done first, and then we can sort out a prop. Check the Gas engine conversion thread: http://www.rcuniverse.com/forum/engine-conversions-92/

Your hull size is about the same size as my body board builds. I run a .60 and a .52 glow engines on 10 - 12 inch props. My second hull has a 25cc Homelite conversion, spinning a 18 x 6 prop. All work fine.

Good luck with the build

DJLaPalme

An Echo 30.1cc engine should be more than enough power. You need to check the rotation of the engine because as far as I know chain saw engines turn cw not ccw like most engines. That is actually a good thing because you can use regular tractor props instead of just pushers, which have a limited selection. Only use nylon, or plastic props. Wood will chip and fly apart in time. I have not used carbon fiber props but they should work too, they just cost a lot more. Dennis