Classic IV build engine suggestions and WHY!

[FoxHunter]

Ok I bought a KF IV fuse from a guy last year in PA (where I live) and I need to consider engine choices. I am considering the following:
Rotax: 583 & 912
Viking: 90-130

Is the 582 a viable engine choice? Price seems to be right.

912 I see just as much problems with this one as the 582....and the prices are staggering. Why? NOT Certified.... 582 priced right and looks to give good power.

Viking engines have not heard much in the way of Viking powered KF's These are priced very well and complete package seems very nice. But that 582 keeps coming back....

I'd like to keep the price low but really want reliability not going to go real fast or need super performance, Just don't want any surprises.

FH~

[jiott]

You really need to decide first whether you want a 2 or a 4-stroke engine; there are major differences between the two. The 2-strokes have MUCH shorter TBO times, use lots more fuel for the HP they produce, are generally less reliable, and sound "funny" in my opinion. If you're OK with a 2-stroke, the 582 seems to be a good one.

[FoxHunter]

Thanks for the good info and will be using it when I make my selection. I like how the four strokes sound too. The 582's sound like they are in a tin box. But the damn price is nice.

FH~

[avidflyer]

I think the Viking engine will be pretty heavy. The Kitfox 4 I'm rebuilding now had a Subaru engine, and it had 20 lbs of lead in the tail to balance it out. Maybe the Viking is lighter, but maybe not. I have a 912 in the Kitfox 4 now, and hope to keep it under 650 lbs. That will be down from over 800 before with the Subaru. Not all of that extra weight can be blamed on the Subaru, but a lot of it can be. Another option perhaps is a Jabiru 85 HP 4 cylinder. I have close to 600 hrs on the one in my Avid Flyer and I like it. It comes in lighter then the 912, but I think an 80 HP 912 would out perform it in the same airplane. JImChuk

[FoxHunter]

Ok thanks some really good info. All being considered.
FH~

[Dusty]

If your intention is to fly local (50mile) the 582 is a great engine but 70 mph is a realistic cruise v's 90 for he 912. I fly my brothers 4 with a 582 which outperforms my 912 powered 4 in takeoff and landing and is marginally lower climb rate. Add a passenger and the 582 starts to lag behind. Fuel burn surprisingly is similar per hour but at a different cruse speed! Both engines are are awesome and suite the 4 very well with the 912 at the upper end of the weight/cg limit of a 4. Your sensible choice is rotax be it 2 or 4 stroke.
I have recently been flying with a jabaru powered Avid and although not a direct comparison it falls midway between the two in cruise but is not startling in takeoff or climb. From what I have seen here the 582 has a better reliability record.We have a few Viking powered aircraft (non kitfox) that are only marginally better than the 912 but their weight rules them out for a 4.

[109JB]

I would also vote either 582 or 912, leaning toward the 912. I remember somewhere reading that the acquisition and operational cost even out about 800 hours if comparing new to new. This is because the 582 needs more frequent overhaul and consume more fuel.

The reason I say 582 or 912 is because they are proven on this airframe, have installation kits, engine mounts, etc available. The 582 you can have about a 550 lb airplane. I'm hoping to have about a 600 pound 912 powered Kitfox for my project airplane. Might be wishful thinking though. Will have to see.

[FoxHunter]

John,
What is the furthest you have flown in a KF IV with the 582 in miles?


EK~

[avidflyer]

Not John, but here is a video of Joey Myers flying on one of his trips between California and Idaho's Johnson Creek. His trusty 582 in an Avid Flyer. He has quite a few other vids if you look through his channel. Another guy who is on the AvidFoxFlyers Forum flew his 582 powered Avid from California to Conneticut. JImChuk
https://www.youtube.com/watch?v=O5cqalZuONw tried the link after I posted it and it didn't work for me. look for Headed to McCall ILov2fly that's the name Joey goes by on utube.

[109JB]

John,
What is the furthest you have flown in a KF IV with the 582 in miles?


EK~

Well not that far yet because I only got it last fall. However I have had it about 100 miles from home. That's only because I haven't had the time or opportunity to take it anywhere especially since this whole COVID-19 thing started. With the 2-stroke the concern for me is not going on a cross country somewhere, which would be constant RPM cruise conditions. The concern, which is not really a concern, is stuff like take-off and landing practice where temps and RPM are up, then down, then up, then down. I say it is not really a concern meaning I'm not afraid of it. It just requires minding the store so to speak. In colder weather particularly I have found you need to pay more attention to engine temps in the 2-stroke.

[FoxHunter]

Not John, but here is a video of Joey Myers flying on one of his trips between California and Idaho's Johnson Creek. His trusty 582 in an Avid Flyer. He has quite a few other vids if you look through his channel. Another guy who is on the AvidFoxFlyers Forum flew his 582 powered Avid from California to Conneticut. JImChuk
https://www.youtube.com/watch?v=O5cqalZuONw tried the link after I posted it and it didn't work for me. look for Headed to McCall ILov2fly that's the name Joey goes by on utube.


Ok nice videos he has. Im interested in both if I can find a decently low time 912 Ill do it but the 582 might work for me with the occasional trip out of PA. Mostly withing 100-200 miles of KHZL.

Ed~

[FoxHunter]

Well not that far yet because I only got it last fall. However I have had it about 100 miles from home. That's only because I haven't had the time or opportunity to take it anywhere especially since this whole COVID-19 thing started. With the 2-stroke the concern for me is not going on a cross country somewhere, which would be constant RPM cruise conditions. The concern, which is not really a concern, is stuff like take-off and landing practice where temps and RPM are up, then down, then up, then down. I say it is not really a concern meaning I'm not afraid of it. It just requires minding the store so to speak. In colder weather particularly I have found you need to pay more attention to engine temps in the 2-stroke.

John,
I have been reading the Rotax site materials and I believe that Rotax has optimized the 582 to be a more reliable power plant now. They have been around for a while........I like having a true aviation engine in my airplane (not ready yet but need to think about it) not a car conversion. Any other help would be appreciated. I would actually like to fly with someone in thier 582 powered KF if there any Kitfoxxes near me in PA. ??

Ed~

[Slyfox]

only one thing I can say. you get what you pay for. with that, I'm going to fly my kitfox 4 with the 912uls and have a ball, with no worries. have a nice day.

[FoxHunter]

Ok, Thanks for the input.

EK~

[Slyfox]

I wasn't trying to be a smart... but I use to have the 912ul, it did do quite well with that engine. I flew the pants off the old engine. I upgraded my engine a few years ago to the uls, wow! that was very nice. I love the power and the cruise is right at 115mph with 27.5 tires. take off is out of site, although I do have the IVO inflight adjustable medium. All around performance is outstanding and all I can say is I love my kitfox. you need to figure out what you want in your airplane, not how far out you are going to go, but what you want for each flight. If you don't want all the power, you just pull back on the throttle, I do that a lot for low and slow, but when I want to get with the program and get to where I want to play, I got the speed. take care.

[FoxHunter]

I wasn't trying to be a smart... but I use to have the 912ul, it did do quite well with that engine. I flew the pants off the old engine. I upgraded my engine a few years ago to the uls, wow! that was very nice. I love the power and the cruise is right at 115mph with 27.5 tires. take off is out of site, although I do have the IVO inflight adjustable medium. All around performance is outstanding and all I can say is I love my kitfox. you need to figure out what you want in your airplane, not how far out you are going to go, but what you want for each flight. If you don't want all the power, you just pull back on the throttle, I do that a lot for low and slow, but when I want to get with the program and get to where I want to play, I got the speed. take care.

No offense taken but I noticed. Anyway. I dont want to take out a builders loan for a Kitfox build, and I'm not made of money. I just wanted to tap the knowledge potential of the forum to the fullest extent. So far the answers were not what I expected, so I AM getting good feedback and tips. I hear about certified engines going quiet all the time, some with one hour some with 1,200hrs. Last year two of the best builders/ pilots around here were lost to a supposed engine out situation 5 miles from the airport and went in the swamp in NEPA. The engine was one of the more expensive well renowned and the plane was an RV.............

I always thought that two strokes were really unreliable and doing some research and putting out the feelers here, I stand corrected! So I was considering a Viking but looks like a lot of complexity under the cowl. Rotax has been around for a long time, as well as Hirth (even longer). I read the history of the Rotax engines and the downfalls and Rotax has improved the line. I have also read that Rotax has reduced the two stroke line down to just the 582......................I know the TBO is 300hrs and haw much a rebuild costs and the 912 tbo is wayyyyyy longer but the rebuild is more (as expected). So they balance out with the exception of HP. There is an autogyro that flies over my house all the time at about 3000ft and its a two stroke enclosed cabin (when it came down for a low pass I noticed this) and looks cool.

So keep your thoughts , Ideas and suggestions coming because I am being informed all the time.
Thank you
Edwin (Ed) Kania

[Slyfox]

when I got the engine from John at kitfox I went to pilot bank for the money. I got the engine, all firewall forward and the prop. I have since paid off the loan by doubling up on the payments, I am now loan free and the kitfox is all mine. I think I now have about 800 hrs on the engine and running very nice. I use auto fuel and with 10% alki and it hasn't missed a beat. I figure I will be able to put a bunch of hours on this engine. I personally wanted the most horsepower and the lightest aircraft possible, mine is right at 650, but I have some super things on my bird. Like grove gear, 27.5 tires, tail wheel is the T3 with the 8inch matco, love that.

[FoxHunter]

when I got the engine from John at kitfox I went to pilot bank for the money. I got the engine, all firewall forward and the prop. I have since paid off the loan by doubling up on the payments, I am now loan free and the kitfox is all mine. I think I now have about 800 hrs on the engine and running very nice. I use auto fuel and with 10% alki and it hasn't missed a beat. I figure I will be able to put a bunch of hours on this engine. I personally wanted the most horsepower and the lightest aircraft possible, mine is right at 650, but I have some super things on my bird. Like grove gear, 27.5 tires, tail wheel is the T3 with the 8inch matco, love that.

Well My plane is not going to be a tail wheel at least for now with the covid stuff and all getting certd is hard. but I live near lots of airports and lots of private land that I cannot land on so the cool tires are out for now. I want a plane that I can go fly and get away from the world and take it all in. Just me and my dog. Taking trips long and short. not interested in sand bar hopping or landing on mountains (for now) just like to cruise.

EK~

[109JB]

That is in my opinion the greatest thing about the Kitfox. Sounds like for you a basic 582 powered fox would fill the bill right now. Later on if you want there are different landing gears, tires, engines, props, skis, floats, amphibious floats, and so on. You can start off basic and move from there if you want.

[Slyfox]

the best tires on the fox by far are the 22" nanco's ran those for a long time.

[FoxHunter]

That is in my opinion the greatest thing about the Kitfox. Sounds like for you a basic 582 powered fox would fill the bill right now. Later on if you want there are different landing gears, tires, engines, props, skis, floats, amphibious floats, and so on. You can start off basic and move from there if you want.

That is what I am thinking but it is early.

Thanks
EK~

[HighWing]

Great discussion. My first build flew in 1998. Rotax 912ul. First 9 years a group of us flew from California to the back countey - improved strips - of Idaho. The first two years one of the guys flew behind a 582. Being a close nit group we always stayed together in loose formation. That meant the 582 guy set the pace. Only one issue I remember. On the way home one year approaching the Sierra Mountains, mr. 582 was concerned with climb capabilities on a rather warm afternoon. We all stopped and he unloaded all of his camping gear onto other guys planes. Then we all departed. He found that he still would be unable to clear the mountains and graciously told the rest of us to continue on. Embarrassingly we learned that our buddy spent the cold night half way up the mountains on a dirt road without camping gear. I had no issues in 900 hours with that engine. My second Model IV also has a 912ul. Purchased used with 250 hours. The plan is to go to the 100hp + Zipper kit as funds become available. Interestly, the guy with the 582 went to the 912UL and later added the Zipper Kit and no issues. Another friend had a IV with the Jabiru. Retorquing the head bolts every 50 hours ?? Adding oil after every flight ?? Not for me. Granted when Rotax went to the ULS there were issues early with start and shut down - witnessed that, but issues? Thousands out there and only the ones with the occasional issues talk about them. A much clearer picture of dependability would emerge if everyone posted issues or non issues after each hundred hours. Just my opinion

[FoxHunter]

Great discussion. My first build flew in 1998. Rotax 912ul. First 9 years a group of us flew from California to the back countey - improved strips - of Idaho. The first two years one of the guys flew behind a 582. Being a close nit group we always stayed together in loose formation. That meant the 582 guy set the pace. Only one issue I remember. On the way home one year approaching the Sierra Mountains, mr. 582 was concerned with climb capabilities on a rather warm afternoon. We all stopped and he unloaded all of his camping gear onto other guys planes. Then we all departed. He found that he still would be unable to clear the mountains and graciously told the rest of us to continue on. Embarrassingly we learned that our buddy spent the cold night half way up the mountains on a dirt road without camping gear. I had no issues in 900 hours with that engine. My second Model IV also has a 912ul. Purchased used with 250 hours. The plan is to go to the 100hp + Zipper kit as funds become available. Interestly, the guy with the 582 went to the 912UL and later added the Zipper Kit and no issues. Another friend had a IV with the Jabiru. Retorquing the head bolts every 50 hours ?? Adding oil after every flight ?? Not for me. Granted when Rotax went to the ULS there were issues early with start and shut down - witnessed that, but issues? Thousands out there and only the ones with the occasional issues talk about them. A much clearer picture of dependability would emerge if everyone posted issues or non issues after each hundred hours. Just my opinion

Wow, some very good points, got some high mountains out there. the 3 H's are tough. wait till very early morning and try again. Well I believe there a lot of those 582's flying around doing very well at what they do get around. I might try one out not sure, and then switch later on.

Thanks
EK~