I'm Trying to build up a 103 legal single seat challenger and this will require a single cylinder engine. 277 rotax is one choice. Has anyone been powering their plane with an engine from a powered paraglider? (compact radial MZ34?)
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I'm Trying to build up a 103 legal single seat challenger and this will require a single cylinder engine. 277 rotax is one choice. Has anyone been powering their plane with an engine from a powered paraglider? (compact radial MZ34?)
I believe quite a few people have used these engines for ultralights. Actually 30HP is on the large side for a PPG unless you're a big guy of flying tandem.
Gonna vibrate more than a 2 cylinder engine, though.
There are other engines in that range, including the 28HP Hirth F33 and the new 35HP Aerocorsair Black Buill.
Dana
is the 277 still in production in Europe? I see there are still some spare parts available for them. I would rather not use a belt reduction so this is the route I will probably have to go.
Here is info on the Polini engine. Belite had a bulk buy going for $ 4495
https://jameswiebe.wordpress.com/201...e-ever-except/
You can still find all the Rotax engines here in the US. May not be new but rebuilt. Also consider the Kawasaki 440 series.
Belt reduction ( modern belts) are as reliable and much lighter than a gear box.
Getting weight down is based on constant vigilance. Every part scrutinized for weight v utility. Surprisingly paint often seals the deal overweight. Consider 2 coats of exterior acrylic paint. Polyfiber, and others, can push paint weight 15#. Consider light fabric (finer weave) fills faster.
best of success.
Jim
Sacramento
Chapter 52
The 277 is still made, or was being made a few years ago. I understand that Rotax won't sell them individually but you can by them in lots of 25 or maybe 50. Steve Beatty (Airscrew Performance is his company name) still had some brand new ones a few years back. I'm not recommending him, just saying that he's a possible source for a new 277 engine. The gearbox is another story. I don't think Rotax has made an "A" model gearbox since the late 80's and they are getting scarce. You can still buy the internal parts and rebuild them, but it's costly.Quote:
Originally Posted by aeroschmitz
I think the best engine currently available in the HP and weight range of the 277 is the Polini Thor 250. It's pricey, but it's a thing of beauty. Here's a page with a lot of info on it:
http://emg-6.blogspot.com/search?q=polini
The one weak point on the Polini is the gearbox. It's designed for the short light weight props on paragliders. It won't handle the inertia of a longer, heavier prop. You'll need to go with a wooden prop if you want to stay within the specs for the Polini gearbox. The Rotax 277 vibrates something fierce. It was tearing up my airframe. The Polini is smooth as silk, due to a combination of the counter rotating balance shaft and the clutch that disengages the prop at idle. Even with electric start, the Polini is lighter than the 277. It's pricey, though. North of $4500.
The Hirth F33 is another good option. What I've seen with Hirth is that you have to be a good enough mechanic to set up the carburetor and make it run. They seem to often ship the engines with the wrong jets in the carbs an both of the pilots I know who've bought new Hirth engines have had to spend several hours and a few $$ buying and trying carb jets to make them run right. Once they are set up right, they seem to be good running engines. The F33 is considerably lighter than the 277 and also has a really slick optional electric start setup.
I used to be adverse to belt drives as well, based on my experience with them back in the 1980's. I've recently started running a MicroV belt reduction drive on a Kawasaki 440 and I couldn't be happier with it. After tightening it twice during initial break-in, it's required zero maintenance for nearly 100 hours. It's lower maintenance than a Rotax gearbox, which requires oil changes and spring washer replacements. I wouldn't trade that MicroV drive for a gearbox even if one was available for the Kawasaki.
Yup, those 12 spring washers are suppose to be replaced at 150 hours in the A box
Any twin is too heavy at this point for the project. To bad there is no honest weight information on out of production motors like the Kawasaki.
Jim, what belt redrive are you running?
Jim, what redrive are your running?
My fan cooled Kawasaki 440 with exhaust, electric start, and what J-bird calls the "up-up" version of the Micro V redrive weighs 83 pounds. That's without the pull start and carburetor mounted. The exhaust is the style that turns upward and mounts on brackets attached to the cylinder head of the engine, similar to the common Rotax exhaust setup. It makes a nice compact package. Compared to the old 277, this thing felt smooth as a turbine engine. I'm very happy with this Kawasaki power package. Attachment 5272Quote:
Originally Posted by aeroschmitz
Have you looked at J-Bird catalog ? They have new Kawasaki engines in addition to many others including the Rotax. http://j-birdengines.com/ One of the quirks of the marketing is that you need to be aware that some of the prices are for engine cores only - starter, carb, reduction etc are to be added on.
I have a Kow 440 B core available. I am using a MZ201 in my Koala with belt reduction of 2:1. It, like all the other small Fishers, ( FP-series) will not make weight and I am going E-AB.
Hope this helps.
Question: is your plane a Challenger 1 or a 2 with the back seat removed? Is it already built ?
If you go with a Bing Carb take the time to watch the EAA hints for home builders video on the Bing carb ( several in a set) by Brian Carpenter. Bings are a bit of chore to set up correctly but once done they work fine.
its a single seater challenger already built that I have been removing heavy chub off ofQuote:
Originally Posted by Jim Heffelfinger
its a single seat challenger already built that I have be cutting the fat from
I have 67 lbs to work for total weight of the powerplant. (I weighed the airframe and prop)
Is that with a parachute? If not, you could probably get one of the hand thrown parachutes that Belight uses and come up with an extra 12 or 14 pounds of weight allowance.
With 67 pound allowance, you could possibly just squeak by with a 277 but by the time you built a mount and put oil in the gearbox, you'd be right at the limit. You'll almost certainly need a fan cooled 277 on a Challenger. A free-air in pusher configuration is very hard to keep cool. Mine was mounted above the wing on a very clean airframe and I could not keep it cool without running it overly rich or having a large air scoop on the cylinder head. The vibration was so bad that I was never able to make an air scope last much more than 10 or 20 hours. I tried three different designs out of aluminum. Fiberglass or carbon fiber would probably be more tolerant of vibration but I decided to go with the Kawasaki instead.
The other problem with the free air 277 was the excessive cooling on low power descents. I had a free air 277 on a very clean air frame and it was necessary to pull power back to idle for landings. During the descent, even from 500 feet, the engine would cool to where the CHT went below 250. I usually use 250 as the minimum temperature for the first takeoff of the day. The Rotax engines with steel cylinder lines are really prone to cold seizures if you put full throttle to a cold engine and the piston heats up faster than the cylinders. So touch and go landings were always nerve wracking for me. I would try to add power gently until the temp came up above 250 but that meant climbing slowly and spending more time at altitudes that provide fewer forced landing opportunities. Fan cooled is definitely the way to go with a Rotax, IMHO. A fan cooled engine cools down slowly at idle because there isn't much wind blowing across the cylinder at idle RPM. The temperature is much more even on a fan cooled engine than on a free air. Water cooling is even better, way better in fact.
If you're within a few pounds of legal weight, not carrying more than 5 gallons of fuel, and fly responsibly within the FARs, there's very little chance you'll ever get ramp checked. Even in the case of an accident, if the airplane looks like an ultralight and isn't sporting N numbers, the NTSB and FAA are happy to consider it an ultralight. I've read that it costs the NTSB a minimum of about $20,000 just to open an accident investigation case. If it's an ultralight, they can just walk away and turn it over to the county sheriff or highway patrol because it's a vehicle and not an aircraft and therefore not under their jurisdiction. I guess the one place where being overweight might be a problem is if you had UL insurance coverage and your aircraft didn't meet the specs for a UL. I can imagine (although I've never heard of this happening) that an insurance adjuster could weigh the wreckage and deny a claim if the aircraft was seriously overweight. I'm not encouraging anyone to flaunt the law here, just saying that if you follow the spirit of Part 103 and don't create a hazard to yourself or others by flying irresponsibly, there's nobody out there with a set of scales likely to come looking for you.
The Mount is already on airframe as it was on when I weighed the project. I plan on mounting the engine right side up to improve cooling and get around all the inverted engine issues. I was unaware of the cooling issues when running free airs.
thanks for the info!
As you may have inferred by wakataka you might be disappointed by the 277 as a power source.
NikaSil found in a number of engines has greatly increased the reliability (and weight reduction) of these small engines. https://en.wikipedia.org/wiki/Nikasil.
As I mentioned in my first post to you the road to Part 103 success is paved with scales all along the way. Belite has the most contemporary struggle with a legal commercial product. James has a whole list of weight saving products. You will notice that he has lightening holes everywhere. His planes are fairly priced considering the use of carbon and very limited production numbers. Part 103 is a constant battle with weight and performance (safety) .
When building to part 103 Every part of the plane is scrutinized for weight savings. I am sure you are realizing that starting with a built plane is a bit of a handicap. Even prop selection has several pounds of difference ( let alone the allowable mass for the reduction) The education curve is pretty vertical.
Having enough power to have a reasonable ROC is a safety factor. When wing loading gets as low as UL levels you are a feather in the wind.
Best of success for your project.
jim
I often wonder why someone would put the time, work and money into something like this trying to meet Par 103. When there are some very nice airplanes that do meet Par 103 and do not use single cylinder two stroke engines. As mentioned in one of the above post you have Belite, if money is burning a hole in your pocket. But if you can build, weld, for almost nothing you can build a Legal Eagle compared to the Belite. You will then have a nice twin or four cylinder, 4 stroke and many hundred of hours flying your fun airplane at a fraction of the cost of what that conversion trying to meet Par 103, in something that really will not make it and be a joy to fly. That Legal Eagle will be a Hoot or blast to fly, as would the Belite. Not so with this project you are working on. JMHO.
Tony
Yes, there are a few of the open air flying coleman tent type airplanes that probably would make part 103 with twin cylinder engine. I fly in northern Minnesota so I need an enclosed plane like the single seat challenger.
Interesting power/weight relation
TBO > 500 h
almost vibration-free
http://www.aieuk.com/category/products/
price ???
cool link
Why meet 103? Because its a worthwhile challenge. I have no desire to give any more money to A/P mechanics for annuals and I don't want to get a repairman's certificate and go the EAB route.
I guess letting 103 wither on the vine is one way to keep light sport on life support and keep the orders coming in for $125,000 rotax powered planes from europe.
There is a reason Rotax hasn't made that 'A' gearbox for many years-- it was very trouble-prone. Even with good maintenance practices.
The Challenger was a great design and it still is. Thank you for your efforts in keeping this old girl flying! The 227 was a great engine in her day, compared to what else was available then, but Rotax divorced itself from their US based singles and twins a while ago, after basically declaring them all too old and no longer airworthy. Now, I'm well aware that was just the lawyers and bean-counters talking, and there are still enough parts around to keep the existing ones flying for a while longer, but I'd recommend snooping around for an alternate that's still supported by at least an owners group, and won't put your girl appreciably over the mystical 254 number. Belt drives are light and simple, and if you break a belt, you still have plenty more to get you home. What you see is what you have: no mystery as to what is going on inside the gearbox. You may want to snoop around for a lighter prop, though...
old girl??! my challenger is 48 years younger than my chief!
The wankel motor that Dick M. has shown us goes for a cool 15k in british pounds. If you want to order a dozen you can possibly get the cost down to about 10k. But it is a sweet motor at 22 lbs. core weight at about 11 inches tall 14" wide and reduction drives available, which would be needed as it develops 40hp a 8 grand with only 27 ft.lbs. of torque. If you got the bucks it's out there. The rep says it's not a certificated motor with the FAA so experimental or 103 would be all you could do in aviation use unless UAV.
what airframe did you have a 277 mounted on?
My 277 was mounted on a Sun Seeker ultralight. Kind of a rare bird. Only 17 were produced before the 20-20 hit piece killed the ultralight business.
Here's a video of it
https://www.youtube.com/watch?v=XLs2LsgOErI
A very neat bird! I did a search for the 20-20 episode but could not find it. Thanks for the link, it clearly shows how the engine is mounted upright in the open. this is what I wanted to do with my challenger to get away from the inverted engine issues. what climate did your fly in? I had researched the F33 hirth (spendy) and they do make a pretty slick kit to mount on a challenger. I think this is probably a better way to go since that engine is in use in a pusher.
It aired in ~1983 and was called "Ultralights, Flying or Dying" I'm sure with the right search you can at least find a transcript of the episode.Quote:
Originally Posted by aeroschmitz
15 minutes on google & youtube resulted in no transcript or youtube videoor "Ultralights: Flying or Dying". Other writers stated their own difficulties in finding that video as well.
Quote:
Originally Posted by aeroschmitz
I fly in Northern California. Never gets really cold here but it can get really hot in the summers. The engine originally had an aluminum air scoop on the head to improve the cooling. It cracked from the vibration. I made another one. It cracked from the vibration. I made another one out of thicker aluminum. It cracked from the vibration. I gave up and just ran the engine as rich as it would stand without a scoop and found I could keep the temps in range. Carbon build up was a little more than before but decarboning a free air 277 takes all of about an hour. A scoop fabricated out of composites might hold up to the vibration. Aluminum won't.
After the second piston seizure, I had the cylinder bored out about 0.002 larger than spec to provide more clearance for the piston. I managed to avoid any further seizures but it was always a worry. The CHT would get down below 250 on the descent to landing. Whenever I was doing touch and go, I was at risk of a cold seizure, which is when the aluminum piston heats up and expands faster than the cast iron cylinder and seizes in the bore.
I think the F33 would be a better option than the 277, but it is spendy. It has a Nicasil cylinder so it's not nearly as prone to cold seizure as a steel-sleeved Rotax. In my experience and from experience of others I know, Hirth engines often require a lot of fiddling to get them set up right. Rotax did their homework and provided charts with the proper carb jetting for different altitudes. Hirth just seems to send engines out with a random selection of carburetor jets installed. They often will barely run when received straight from the factory, so you should plan on buying a selection main and needle jets, and jet needles and spending some time get it running right before you attempt to fly it. Once he got it set up properly, my friend has had very good service from his F33 engine and he wouldn't trade it for a Rotax. He's got it mounted on a ultralight trike and frequently shuts down the engine for soaring. He has the electric start which is real boon for air starting when the thermals give out. An F33 weighs a lot less and runs smoother than a 277, but probably doesn't put out quite as much thrust. I think it would probably get a Challenger in the air, but don't expect spectacular climb rates. Mounting the engine upright should give you the room to swing a big prop, which is key to getting high thrust out of low HP. I was getting over 200 pounds of thrust from my 277 with a 60" IVO prop. I felt pretty good about that until I read that the Wright Flyer produced about 130 pounds of static thrust from 12 hp. It was turning two 102" propellers at only 300 rpm. I doubt if there's been any airplane since that time that's had a better thrust to HP ratio. Static thrust is a pretty good indicator of performance for slow flying ultralight aircraft. Maybe not so much for faster airplanes.
Roughly what was filmed (this was 33 years ago so memory might not be completely accurate) was a reporter came to an ultralight dealer and wanted to film himself flying an ultralight. He'd told the dealer that he was an experienced pilot (he had no training) and refused to wear the supplied shoulder harness because it clashed with the shirt he was wearing on camera (dumb). Ended up with him doing repeated dives and recoveries until he fell out of the plane (no shoulder harness) and died. All on film and on TV. Pretty much killed the industry.Quote:
Originally Posted by VFR-on-top
Please correct any inaccuracies.
Bill H.
http://www.rotaryforum.com/forum/showthread.php?t=29957Quote:
Originally Posted by griffin800
A long ago review of what happened.
Mark Smith at Tri-State Kites (former Quicksilver dealer, still scratch builds them and sells parts) has a copy of the 20/20 video. He will show it to any visitor who asks, but will not allow copies to be made (I guess I don't blame him). From what I've heard, the pilot was instructed to make it look crazy and dangerous (typical muckracking "journalism"). Combine that with a pitch sensitive aircraft that could easily exceed Vne in level flight, and an unbuckled harness, well, the outcome is unsurprising.