Jon Boat conversion

Installing a Rotax 503 with a 2.6:1 belt drive reduction and 60" propeller. Looking for any plans or suggesttions on the engine mount and cage build including materials, strong points, rudder build suggestions.

Thanks
jdw

Welcome to the site. Have a look at this video then ask away.

https://youtu.be/_HksaKif8yA

Thanks Papee. Can you post more links please?

Can a 3 person airboat (aprox 700 lbs payload) hull be foind innthe price range of a Jon Boat? ( Say $600?)

Three people in a mini is not going to do well. Even with a rotex or othe reduction setup any mini will struggle with three people on board. I'm not going to say they won't do it but it will work hard for sure. Add the narrower Jon Boat hull to that and it would be even harder.

I realize there are some that have no choice but to use a Jon Boat and they will work but have their limitations and flaws as I mentioned in the video. There are a few videos up at the chalkboard and should show with that one. I have some more raw footage done going over the green boat exposing more but I've not yet been able to get them processed. I do the best I can because of my health. I have to take what each day gives me.

Thanks for your help. I've seen all the vids you have up and definitely is enlightening. I will input progress on the build, and will probably end up buying a used hull, if you know of one. I do have more HP engines available which can produce around 350 lbs of thrust. Will obviously be experimenting with weight, distribution, hp, and hulls.

Thanks again!

Assuming even distribution in 14' Jon Boat, and 60 hp with 2.6 reduction and 60" 5 blade prop pitched at about 12 degrees, do you have a suggestion on vertical thrust angle? (Essentially engine mount angle). Also, what gauge aluminum sheet do you recommend for twin rudders that extend about 40" vertical height?

Vertical thrust really depends on how your weight is distributed. No two boats are the same really, others say to start out parellel to the part of the hull you will be running on when on plane. I always give it about 1/4" towards the water to push down on the front a bit to eliminate any porpoising. Just be sure to work some flexibility into your mounts for adjustments up or down.

You didn't mention what type rudders, for easy stop sign type I used .125 because it's what I had but you could go a little lighter. You'll have to check out aerokirk or Corkys builds to see what they used for the airfoil type. I always use the stop sign type because they are much simpler with no offset on the pivot. There really isn't any noticable difference in performance or mechanical advantage with the thrust numbers we see on the minis in my opinion.

Can you explain stop sign type? Pardon my ignorance.

Just a single piece of sheet aluminum rather than the thin aluminum foam filled airfoil type.