engine swap

[wyodan59]

I am wondering if anyone has any experience with changing the motor on a kitfox or avid. Can larger engines be put on? Say from a 582 to a 912. What needs to be changed besides the engine mount and the cowling? Will the airframe need any modifications?

[Dana]

Well, you'd certainly have to look closely at the weight and balance... and consider the effect of the additional weight, thrust, and gyroscopic forces on the engine mount and related structure.

[Todd copeland]

Surely the kit fox is an airframe that the 912 is used on so I think it would be pretty straight forward, probably the same for the avid. If the factory supports those engines for the airframe it should be more a matter of $ and elbow grease than anything else.

[Jim Hann]

Remember there are lot of different versions of the Kitfox. All of the comments above should be applied carefully. Aviation writer Amy Laboda and her husband have a Kitfox that they built and later re-engined from a 582 to a 912 IIRC so it is possible, depending on which Kitfox it is.

[Mike M]

Say from a 582 to a 912. What needs to be changed besides the engine mount and the cowling?

i won't ask why you want to change, because you do, and it's yours, so...whatever. my limited experience with 532 on a long-wing avid flyer and 912 on a kitfox showed with the same payload the avid outperformed (by a whole bunch) the heavier kitfox in everything but cruise speed. the kitfox was about 6mph faster.

a choice for more power on a bird with a 582 without changing engine mount, cowl, etc might be a larger rotax built on the same footprint. if you want to ask an expert about it, try "rotax rick" in naples, fl, 239-572-0021.

[JimS]

I have made this swap with my Kitfox IV. After flying it for 12 years with the 582 I got a good deal on a 912 UL and upgraded. My engine actually came off another Kitfox (that owner was upgrading to the 100 hp 912 ULS which takes a bit sturdier mount) so I got the motor mount with it. Had to buy a muffler, throttle and choke linkages, Prop, various hoses etc. oil temp and pressure guages. Did not have to modify the cowl except cut a new hole for the exhaust pipe. The plane had worked well with the 582 and had made the trip from Wisconsin to Sun-N-Fun twice without any problems, But the 912 is the perfect engine for the airframe. Cruise speed is 10 mph faster while burning a gallon less gas per hour.

[wyodan59]

I am wondering about this change because I live at 7000 feet. I have a friend with a paraplane powered with a 582. It struggles to fly with 2 soles when it is hot in the summer here.