Maximum engine size

[n85ae]

I have a 74" prop on mine, I haven't had any problems ... Yes I do
occasionally wheel land it

[WWhunter]

I should add...this 75" WW STOL prop is not on my Kitfox (yet) but rather it is on my RANS S7. The plane has the stock landing gear but is on 29" AkBushwheels so prop clearance is not an issue.

[av8rps]

In my mention about running a long prop on an 0-320, I was thinking about the ultimate STOL prop for a Super Cub, and that is typically a Borer prop with an 82 inch diameter with 43 inches of pitch. That would make for one big bite of air on a Kitfox.

The general all purpose prop for a 150 hp Super Cub is a 74 inch diameter with 54 inches of pitch. Either the Borer or the standard prop will work well I'm sure, all depending on what you want your plane to do. You can find loads of info on the SuperCub.org forum if you want to know more about the best STOL prop for a 0-320 vs the more conventional props.

I'm guessing the 0-320 Kitfox will do just fine with the 74 inch pfop, but the Borer prop would really be a hoot in the back country with some big tires and an extended gear...hmmm? Maybe like the new Kitfox STI but with a big engine

[jmodguy]

Thanks for the input Av8r!

[jmodguy]

I was going through my paperwork couple days ago and I thought I would have to abandon the O-320 for this project. Some of the information that came with the aircraft indicated 1400lb GW spars (.058). I stopped at the airport on the way home and measured the wall thickness with my calipers and to my relief they are the 1550lb GW spars at .065!
So far so good...

[jheit39]

take a good look at the O340 from Titan..

[jmodguy]

Don't tell anyone but I am building an IO-340 with a FlyEFII kit... I have an EFII kit, a new ECI case and 340 stroker kit.
Pulling together the rest of the parts.
Reserved the N number 340KF last night
Remember - Don't tell a soul...

[redbowen]

Since I'm running a O-290D I thought I should chime in. I know all the Rotax guys love there set up, but there are others ways to go and they are great also. If you look at the engines that Kitfox supports it includes the O-235 that has a dry weight (246lbs) 1lb less than a O-290D while the O-290 adds 15hp. Thats basically a free 15hp.
As far as CG goes, its a non-issue. You go 1 degree wing sweep and the 3 leaf tail spring with a bigger tailwheel like a Matco 10" and no ballast is needed. This is how mine is set up and my empty weight is 930lbs CG @ 9.85 and with the wing sweep max forward allowed is 9.5. It is balanced nicely, plus I can lift the tail for take off from a stop. Climb out is 1000' plus, I can bump up against 140 mph wide open. I like to cruise at 2200RPM for a 118mph cruise and a 5.1gph fuel burn. It has the same LSA useful load as a carbon cub and has been the perfect airplane for my mission. I backcountry camp often with a group of guys and we almost always go 1 to an airplane with gear. Most of them fly Maules. They can carry tables and firewood, but they burn way more fuel and can't enjoy building and flying there creation.
I have looked at future overhaul options for the O-290 and the biggest downside to this set up is parts. One option I am considering in the future is to put O-320 cylinders on the O-290, and yes this can be done. Minimal weight increase and yet another 20hp. I think a O-320 or O-290 is a great option for the Kitfox and I can tell you they are still very sporty and a kickass airplane.

[airlina]

Bryan , What prop do use with your o-290? Thanks Bruce N199CL

[jmodguy]

Thanks Bryan that is very useful data.
Regards
Jeff