Thanx to Nathan i now can give you my idea, Based on a airboat i built a long time ago, this should work out better? Dont worry about scale but it should give you the rough idea.
If you have any ideas for it let me know
Rick

Kinda thinks , it reminds me of one of these ... ( kids got one )

I`ve never seen one of them here in the UK, then again i dont look at kids toys much, now my son is 19. I might see if i can find one here and use the hulls lol the hulls i am making are designed for floats on a sea plane, it should not be too tricky getting it balanced (i hope)

looks neat! it reminded me of an amphibious airplane, minus the wing of course! good luck and keep us posted!

move the engine back, replace prop with apc, and you should be all set

(engine move back because it will tip forward and dive with it that far forward....it should be resting on the end of the front step and rear step.)

The engine will get put a little bit more forward if anythingas there is weight hanging back with the pipe , it worked well with the old model the hulls are better designed this time, but thjings will/could change here and there as designs usually do, i have ideas of a adjustable rear spoiler which may balance the boat at differet speeds with 3 channel radio gear, but its all early days for this prototype, the drawing is not to scale so weight,and C of G pivot points will all get sorted on the final build and test drives in the bath lol

yeah, but adding weight will slow it down and a spoiler will act as an airbrake and slow it down also....besides, when at power, the engine will want to tip forward//

(Yeah But ???) take a look at a sea plane on floats and where the engine is, the engine is very far forward and it does not nose dive because it is balanced by the tail end , my air boat will not have the long fuse like a plane so the engine will not be so far farward to get the balace point right . not all spoilers/wings act like air brakes i know there will be drag caused. but if things are set right drag will be kept to a minimum. Wings on a airplane give the right lift but its not like putting the brakes on or planes wouldn`t get off the ground as they use power to get off the ground and do not tip forward.

Knowing a little bit about aerodynamics..... priceless

wings lift though and mekes the plane lighter, so even if there is grad, the less weight will....ahh forget it, build your boat the way you want to...

will do, all ideas make better end products some ideas may work some may not , As there are no specific rules on how these air boats (and there are many different styles)should be built, trial and error are the only way to find out. I`m not saying who`s right or wrong or what design is right or wrong, i am after ideas from all, some i might agree with some i might not, Only the end product will tell if i worked it out right. and im not here to have a row or start a conflict as this is a hobby and it should be fun. If anybody thinks my idea stinks it don`t bother me, and i wont hold it against you. lol

ok then, use the setup you want to, but make the motor mount adjustable so you can move the motor so you can fine tune the way the hull runs

yes right on, the angle of the engine can/will be adjusted by simply adding or removing washers on the mounts, i could not show this on the drawing as i only just found out how to draw on the PC, then had to find out how to change it from bit map to jpeg. never had PC`s when i was at school !! [&o]

i meant adjustable as in you could move the motor back or forward, but angle will pretty much have the same effect

yes, adjustable front to rear. sorta like this.

Ok right, i didn`t think i would need to move the engine once i have the balance point right , but i could make the engine mount moveable on the hulls if i set a row of blind bolts into the decks about 1/4 inch apart for fine tuning ?

yup, that way the motor can be moved forward or backward incase that sort of adjustment is needed.

thats a nice mount 89ram with a low centre of gravity, is that a foam hull ?

thanks rick, low cg was the whole point to this particular engine stand design. i held the motor by the crankshaft and let it hang, and that's how i got the angle.

yes, it's blue insulation foam, 2 pieces 1 1/2inches thick laminated together with gorilla glue.

basic and smart thinking to get the CG low on mine i had to unbolt the front of the engine face the head down and keep the carb upright for ease of use, the tricky bit will be getting to the glow plug so i have to get a remote glow adapter

have you run the engine like that ? do you use a plug with an idle bar? do you have any problems starting it ? i have run inverted engines before and had a few problems

ive heard starting nitros inverted is hard, but for some reason after you can get them to start, they run better inverted

yes, it runs like that. no idle bar plug currently. i have'nt had any starting problems. i use an electric starter and prime it with the glow on so that it has no chance of drowning the plug. i've flown nitro planes for 15 years with motors in various positions. the revo aboard was for size comparison.

yes starting can be a problem as the plug can foul up thats why i have asked about using idle bar plugs as this can help stop fouling,

carb up and head down? that's an interesting thought. i don't beleive any of my motor crankcases are built like that.