Rotax 914 in a Kitfox

[chipper2128]

I'd be interested in hearing from any members who have installed or are considering a Rotax 914 for their Kitfox. Obviously a more expensive/complex engine than some of the other options, but for high density altitude operations would it be worth it?

Thanks

Mike

[jrthomas]

Hey Mike, Since no one else has responded, I'll put in my 2 cents worth. I'm at about 430'msl so I can't say much since you have to contend with much higher altitudes. I would think a 912S in any model KF would be all you would need if up to 10,000 ft or so. I can't see an extra $12,000 for 15 horsepower.(List price is over 31k) Every plane I've been around with either 912 had an abundance of power, especially Kitfoxes. Model III's with 582's are usually off in about 200ft. Unless you're just rolling in cash, I would suggest the 912S. I'm anxious to hear what the others think. Later, James Thomas

[DesertFox4]

for high density altitude operations would it be worth it?

The 914 is no doubt a very good engine. Complexity is the word that comes to my mind. With the introduction of the 912S 100 hp, maybe, within the Kitfox line, the 914 became slightly less relevant. Before the 912S you had two choices. 80 hp or the 914. Now the 912S seems to be filling the role for more power nicely and with much less outlay of cash and with the simplicity of the 912 80 hp.
I've only flown in one Kitfox that was 914 equipped. It was somewhat tempermental. Hard starting. Not saying they all are but that one was. So far I have yet to be someplace where I thought the 100 hp 912S was lacking and I'd wished for a 914. Course, I ain't been everywhere yet.

[darinh]

Loved my 914 in my Kitfox (Series 7)and I never had any of the problems or issues that have been mentioned. Started as good or better then my 912UL and ran like a clock. I barely had it broken in (60 hrs.) so it may have been that the problems crop up later in the engines life. I did have some sputtering one time and thought is was the wastegate but it ended up being a clogged fuel filter from deteriorating Mil 6000 fuel hose. There is not arguing they are more complex with the TCU, turbo, pressure regulator and electric fuel pumps though. I did say loved at the beginning because it has been sold...I need more room for the 3 boys I have. Having said all this, I mostly agree with everyone else that it is not worth the extra $12k. A buddy has a Series 5/912S and the benefits of the turbo really start to show themselves as you climb high but we never flew like that...the Kitfox is great down low. I was about 10 - 15 mph faster at 5000' and I could out-climb and maintain that climb while he had to push the nose down a bit to keep the speed in the comfortable range. If I built the same plane again, I am pretty sure I would not spend the coin on the 914 again...the performance didn't outweigh the benefits in my mind.

[av8rps]

Just a couple comments on the 914 in a Kitfox;

The Just Aircraft (Highlander) factory crew learned after trying every possible engine that the 914 was the engine that provides the best performance in their Highlander.

However, a lot was learned before the 914 performed correctly. Mostly small stuff, but two really important things that you have to be aware of;

- The turbo intake needs cold air. Hot air destroys the advantages of the turbo boost. So make sure your intake brings in cold air.

- The 914 has two electric pumps that run all the time, with a fuel system that constantly recycles the unburned fuel back to the fuel tanks. It is common to see builders just run lines off the header tank as it is easiest, but the fuel absolutely needs to go back to the main tanks in order to allow the hot fuel coming from the hot engine compartment a chance to cool off before being sent back to the engine compartment again. If the fuel isn't allowed to cool off, it is easy to get fuel vaporization, or vapor lock, causing fuel starvation (not fun...) So once again, it is critical the fuel being sent to the engine compartment be as cool as possible.

The 914 if set up properly should make a lot more power than a 912s. It is 100 hp continuous, and 115 hp for takeoff and climb. If you don't run the airbox on the 912s, (which many don't it seems) you have a 95 hp engine. To furthe demonstrate the power differences, just study Rotax's torque charts to identify the real difference between their engines.

A few years back a magazine did a fly off between IO-240 powered Kitfox, and a 914 kitfox. End result, the 914 outperformed the IO-240 in climb, takeoff, and top speed. Having the benefit of high altitude performance was just added bonus.

Now, like most of us here, I have a problem with the price of the 914. But if one already might have a 912ul laying around (or access to one), for $8500 Bob Robertson of Bullyhawk in Canada will sell you an OEM 914 upgrade kit, giving you a powerful 914 for a very reasonable price. Yeah, a complex engine by the time you are all done installing it, but a real powerhouse for it's size and weight.

Paul S

[Dave Holl]

bcbcbc
If your so well off why bother reading team kitfox?
For most of us we have to work to a buget!
Most aircraft have the ideal HP engine for best efficiency what that would be for the kitfox I don't know but I would guess for a MK 7 that would be 90HP, but if you are wanting to operate at high levels the 914 would be the way to go.
Dave

[DanB]

Dave, Ignore the last post by bcbc...he is a previous member throwing a temper tantrum. Poor thing

[Kevin C]

I have a 914 in my model 6/7 that I would consider selling for $20,000. Living at 800 msl and staying below 2000' it is not needed. About 100 hrs engine total time. Heck for $50,000 you can have the whole plane with wheel gear and currently mounted on baumann straight floats. It is the yellow and white floatplane on the kitfox site under "completions". Also has nice trailer for hauling. It would be fun to build another one!
Kevin

[kenjfrance]

I've got a 914 and Hoffman CS in a 4.....I live in the mountains and this thing is just plain fun!....1031 hrs. and counting....lots of different "issues", but had great help from Rotech Research nearby....pulls to VNE....1,700fpm @ 3,000' and 1,200fpm @ 10,000' (wheels).....off the water in 6 secs. on FL 1260's....nothing flies like this on 4gph....started out at 685# empty...now @ 700#.