Ultra light engines help

[ted gilbertson]

I'm looking to buy a challenger II, it has a 2703 Hirth engine in it. I have heard they are only good to recycle for beer money or they're great. One guy claims if you take care of them and use an egt and the right oil they will last. Anyone have any input on this engine. I can get the plane for around $3000 but if i have to put a Rotax in it I could be way too far out for a fixer uper.

 

[Geico266]

Save your money for a Rotax powered bird.

Any of the 2 cycle engines requires specialized skills to keep them flying and working properly. They need to be adjusted for temps, humidity, and maintained to the highest order. Even then, it is not a equation of if they will quit, it is a when.

 

[docmirror]

Don't know anything about Hirth. I haven't heard a lot that's good though I won't pass on speculation.

The whole light weight two stroke issue has kept me out of the UL and some of the EXP market. Two stroke engines are good for boats, and maybe for a race bike, but I'm not happy with the reliability factor of any two stroke aviation engine so far. The Rotax 582 is on a lot of planes, but it has some history with warped heads, and bearing failures. Not much better than the Hirth maybe?

So, anyway this is the engine that I would likely convert to. It's a four stroke, started out as an industrial engine with some mods for aviation. Air cooled, and has a starter, alternator, prop, and prop speed reducer all for 120Lbs.

http://www.culverprops.com/big-twin.php

 

[bbchien]

Save your money for a Rotax powered bird. [/QQUOTE]I had a two stroke Rotax break it's crank on me....

Any of the 2 cycle engines requires specialized skills to keep them flying and working properly. They need to be adjusted for temps, humidity, and maintained to the highest order. Even then, it is not a equation of if they will quit, it is a when. [/QUOTE]yes...

 

[Geico266]

The problem with flying on the cheap is that owners usually don't have the money to maintain them properly either. The Rotax 582 requires decarbonizing the engine every 100 hours ( I think) it is rarely done. The crank shaft is suppose to be replaced every 300 hours. Rarely, do owners do this $1,800. Gear box should be inspected regularly, ect, ect, ect.

Rotax 2 stokes are good engines, designed well, but require constant maintenance. I've flown around 600 hours in front of a Rotax 582. I had the engine quit 3 times, all my fault. Go with a 4 stroke Rotax first.

 

[Fearless Tower]

The problem with flying on the cheap is that owners usually don't have the money to maintain them properly either. The Rotax 582 requires decarbonizing the engine every 100 hours ( I think) it is rarely done. The crank shaft is suppose to be replaced every 300 hours. Rarely, do owners do this $1,800. Gear box should be inspected regularly, ect, ect, ect.

Rotax 2 stokes are good engines, designed well, but require constant maintenance. I've flown around 600 hours in front of a Rotax 582. I had the engine quit 3 times, all my fault. Go with a 4 stroke Rotax first.

This is why I passed on the Nieuport replica and decided to pursue the A65 powered Pietenpol.

After a fair amount of research, I came to the conclusion that a two stroke engine like a Rotax can be safely operated, but it requires more maintenance and different flying technique than I wanted to get into.

To do it right takes dedication - It isn't the kind of thing you leave in a hangar and expect to just go out once in a while and fly when you feel like it.

 

[zaitcev]

So, anyway this is the engine that I would likely convert to. It's a four stroke, started out as an industrial engine with some mods for aviation. Air cooled, and has a starter, alternator, prop, and prop speed reducer all for 120Lbs.

http://www.culverprops.com/big-twin.php

From what I gather, although their airplane is much hated by homebuilders, the Big Twin engine is relatively well regarded, although it's a single engition engine. It was in use on Neuports, and some people install it on Kolbs and the like.

Main alternatives are HKS 700 (used to come stock on Gull), and 1/2 WV engines, chief of which is Hummel (just coming online for Belite). I think Legal Eagle is one common user of 1/2 WV, albeit not Hummel.

Most in my ultralight club fly on 2-stroke power and the prevailing opinion is that modern Rotaxes are much better than they used to be, in particular the ignition system. Of course everyone installs the external fuel pump too. One guy flies 45nm cross-country to every fly-in (and the last time he ground-looped it and had to be trailered back). Unfortunately, news of Rotax dropping almost all of their 2-strokes was a setback. And in general, everyone understands the maintenance point that Geiko is making. Fortunately they are retirees, so they can devote the time to it.

 

[tinerj]

At a UL fly-in luncheon, I asked the eight people sitting at the table how many had an engine out in flight. All of them raised their hands. (two-stroke engines)

At a Cessna 120, 140 fly-in, I asked a similar number of pilots how many had had an engine out in flight. None of them raised their hands. (four-stroke continentals)

I am a member of the GAUA (Gateway Area Ultralight Association), but do not fly one because of the tremendous amount of time that must be devoted to two-stroke engines to keep them healthy.

 

[docmirror]

Well, nothing like a 100% failure rate to reinforce the 'which engine' question. lol

 

[X3 Skier]

Unfortunately, news of Rotax dropping almost all of their 2-strokes was a setback. And in general, everyone understands the maintenance point that Geiko is making. Fortunately they are retirees, so they can devote the time to it.

I assume you mean by almost all they are only producing the 582 and not others. Correct?

As a retiree, maintenance of an engine seems preferable to watching daytime TV.

Cheers

 

[zaitcev]

I assume you mean by almost all they are only producing the 582 and not others. Correct?

Yes, 582 is the only one left. But it's a big engine. Back in the day RANS specified it for S-6 and S-7. I don't think anyone here uses it around here. The biggest I saw was 503 IIRC. There's one guy who's still on a 377 in a Quick MXL.