Maximum engine size

[Russway]

I'm still in the dream stage, and I've purchased nothing. Realizing the engine is just as important as the airframe, I've found an interesting option. Superior Air Parts in Coppell, Texas has a build school. You can build a new engine under their supervision, or you can watch while they build it for you. I haven't called about availability or pricing because I have concern about the size. Their smallest is the XP-320 (cubic inches), 160 horse power, at 290 pounds overall weight. I haven't found a definitive limit, but the Kitfox website mentions projects built with all types of engines 150 hp or less. So......., is this engine even feasible? Thanks for your input.

[Danzer1]

Russ,

I have explored just about every engine out there up to 225lb dry. With that weight there are c.g. envelope issues if not careful. Potentially adding weight to the tail and further limiting as the wing tanks empty or flying solo. Neither looked like options/conditions I liked. I would call 290 a no go in my book.

Currently leaning towards the UL 350is, other than high price with the current Euro exchange rate, it is seeming more appealing to me everytime I compare it to anything else.

Greg

[n85ae]

I believe there have been a few O-320 powered Kitfoxes built, wish I could
remember who was doing the installs. If memory serves correctly the
primary reason was for use with floats.

Regards,
Jeff Hays

[airlina]

Russ, I have an I0-240 on my Series 5 that is around 250 lbs and I would say that is about as much as the airframe can stand C.G. wise. With forward swept wings, and my battery in the empennage I keep the C.G. in limits, but with 290 up front, you would be adding lead in the tail to keep her balanced. Bruce N199CL

[Gravity_Knight]

Also curious about this. I have a sport license now, but have been considering "upgrading" to a private. Operating at the 1550 instead of 1320 MTOW so I could legally run a larger engine, and still fill up on fuel etc. I live at 6700ft elevation in colorado and fly to 14,500 in the mountains quite often. I don't have a Kitfox yet either, but plan to buy one with a 912, so I'm just looking at options for down the road...

[Russway]

Thanks all. I figured as much. I knew that the mere idea of a build your own option so close to home was just too good to be true.

Russ

[Gravity_Knight]

The Lycoming IO-233 doesn't look too bad... 115hp, 2400 TBO, and 213 pounds dry.... new it's $25,000 which is not in my budget, but one can dream

[War Eagle]

Also curious about this. I have a sport license now, but have been considering "upgrading" to a private. Operating at the 1550 instead of 1320 MTOW so I could legally run a larger engine, and still fill up on fuel etc. I live at 6700ft elevation in colorado and fly to 14,500 in the mountains quite often. I don't have a Kitfox yet either, but plan to buy one with a 912, so I'm just looking at options for down the road...

Another option you could go with is the turbo charged Rotax 914. No density altitude problems and less weight and full 100 HP to somewhere about 16k feet. You'll likely save at least 70 to 80 pounds dry weight and climb rate will be pretty nice too.

[GuppyWN]

Another option you could go with is the turbo charged Rotax 914.

MSRP is $32 tttttthousand!

[Av8r3400]

I can think of no reason what so ever that a person would want to put a 300# 320 Lycoming on a Kitfox.

Any power gain would be more than negated by the weight of the motor, not to mention the ballast needed in the tail to balance that giant anchor hanging on the nose. Plus you need to factor in a 10 GPH fuel burn (yes, that is realistic) so you will need to haul around a ton of fuel all the time, too.

An O200, IO240 or 233 Lycoming are probably near the weight limit for a Kitfox to still have a reasonable useful load.

Even at your altitudes, I think you will find the performance of the 100 hp 912 to be just fine in what should be a very light weight plane, Sir Gravity_Knight.