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What will replace the Rotax 447 and 503?

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Posted

Came across this article today and thought it was worth sharing. Doesn't apply too much to the Avid Community but I know a lot of us have other projects. I flew for over 10 years behind a 503 and I agree it was probably the most reliable carefree motor they ever made.

 

What Will Replace the Rotax 447 and 503?
by Steve Beste
 
The Rotax 40hp 447 and the 50hp 503 engines are no more. The last available unit was sold in January. Since these engines powered almost every Part 103 airplane and trike on the market, what will replace them? I contacted six manufacturers of Part 103 trikes and airplanes to see what their plans were. Here’s what I found.
 
Why Discontinued?
 
An article in Light Sport and Ultralight Flying magazine explains why the engines were discontinued:
“Rotax stopped producing the 447 and 503 because the molds for the engines needed to be redone,†explains Canadian Rotax distributor Dave Loveman. “Before spending the resources necessary to do that, they asked dealers/distributors to give a projection of sales they expected moving forward, so that [Rotax] could justify the cost. The feedback was that sales for those engines did not justify the cost. In the past, the 447 and 503 were also being used in the snowmobile industry. They have been now replaced with newer models, leaving the aviation industry as the only industry still using the 447 and 503.â€
I would also guess that the company’s successful larger engines have squeezed out the 447 and 503. The 912 and 914 engines dominate the market in the 80-115 hp range. A company has only so much management attention, engineering talent, and factory capacity; much better to spend it on popular $20,000 engines than on a few $5,000 ones. Lastly, there’s a widely-held belief that electric motors will take over the low-end of the market in a few years. Whether this will actually happen or not, it would affect an investment decision being made today.
 
There Is No Substitute
 
There was general agreement that these engines have no easy replacements. Consider what they had:
Reliability (and a reputation for reliability). When I took trike lessons at Kemmeries’ in 2005, their on-staff Rotax mechanic told me that the 503 was the most reliable engine Rotax made. Parts and service availability. Just leaf through a catalog from Lockwood or California Power Systems, and you’ll see that every spring and bolt on these engines is available, in stock, in this country. Plus, these companies will overhaul your engine if you want.
 
Rotax 447

Geared re-drives. All of the substitute engines have belt reduction drives. Although they work, they require more maintenance. And sometimes they don’t work (see below). It turns out that a good re-drive is hard to design because of torsional vibration. Acting as a flywheel, the propeller wants to turn at a constant speed. But the engine is pulsing, speeding up with each power stroke, slowing down with each compression stroke. Usually, the engine’s own flywheel dampens these out. But as you shrink the flywheel to save weight, more torsional vibration gets through to the re-drive, which has to mediate between the engine and the propeller. This stresses the re-drive. There’s an excellent online discussion of this at EPI, a manufacturer of gearboxes. Their conclusion is that there’s no substitute for an adequate flywheel. The upshot for us is that the manufacturer needs to evaluate not only the engine, but the re-drive.
 
Customer acceptance.
 
We light flyers are a conservative lot. If you’re like me, you have enough money to buy only one aircraft. If the engine is a dud, you’re stuck. The manufacturers are in a similar position. They’re all small. None of them has deep pockets. Nor is there a Consumers Reports to tell them which engines are reliable. They pick an engine and take a risk. That risk has just gone up.
And the worst of it is, after they pick another engine and take this risk, they’re merely back where they started—they have added nothing to the value of their product. So what are they choosing?
Don’t Know
Todd Ellefson at Quicksilver wrote that they’re still looking into it. Quicksilver is perhaps the largest maker of ultralight-type airplanes. As such, they have the most at stake.
Travis Brown of Kolb is in an easier position since he sells only kits, not completed airplanes, “there really is no substitute for the Rotaxes,†he says. He’s letting his customers pick their engine. Most customers are picking the Zanzottera MZ 201. He gets good reports from them.
Trike maker Mark Gibson of Manta Aircraft likewise sells only kits and is letting his customers pick their engine.
 
Rebuilt Rotax 447 (40hp)
The smallest manufacturer I talked to was Don Cooney, who makes the Prowler trike. The Prowler is a high-end Part 103 trike that won grand champion ultralight at Oshkosh in 2000 (and best trike at Sun ‘n’ Fun that same year). He makes a few kits over the winter and does other things the rest of the year. With this low volume, his plan is to buy rebuilt 447s. “I flew a Kawasaki 440 for many years up on Long Island. A great motor, but the belt reduction drive was a problem. The 440 is probably a better motor than the 447. But the re-drive is the problem. What we’re all looking for is a good 40hp 4-stroke.†Rotaries? Pricey. Half-VW? 110lbs with the starter and battery. Way too heavy. And high vibration.
 
Kawasaki 440 (40hp)
Kamron Blevins of North Wing trikes has a different experience with the Kawasaki 440 (40hp). It’s the engine he recommends for his Maverick trike. “The Kawasakis have an excellent reputation. The [32hp] 330 is a bit underpowered for the [$1,500] cost difference. You might as well go with the 440.†As to Hirths, he reports nothing but bad experiences with both single and two cylinder models. “I’ve never had one run for any length of time without issues. Out of ten engines [back in 2000], only half the people were happy.â€
Verner JCV-360 (35hp)
Blevins is offering this new 35hp 4-cycle engine as an alternative to the 2-stroke Kawasaki’s on the North Wing Maverick trike. Says Blevins, “we have four out there now. It’s working out for them. It’s not a huge climb rate. 400-600 fpm vs. 800-1000 fpm with the 447.†According to the North Wing price list, the Werner adds $4,000 to the price compared to the Kawasaki 440.
 
Hirth F-33 (28hp)
Terry Raber builds his Aerolite 103 airplane with the Hirth F-33. He’s been doing so since 2008, and is happy with it. He says he will offer the Kawasaki 330 and 440 as an option. He had much to say on the topic of light engines. He thinks the Verner engine is nice, but pricey. He likes the idea of industrial engines such as the Generac, since they are reliable, widely available, and you can easily get parts for them. But at 120 lbs, the Generac is too heavy for his purposes. He’s been looking at electric motors. He expects big changes in those in the next two years. And indeed, he says his next airplane will be electric.
I was unable to reach Paul Mather of M-Squared. But his Breese XL Part 103 also uses the Hirth F-33. So does the Belite Superlite, named 2010 Grand Champion Ultralight at 2010 Sun 'n Fun.
Bautek-modified Briggs & Stratton (38hp)
German hang glider and trike maker Bautek is also alert to the virtues of industrial engines. They have taken a Briggs & Stratton Vanguard 4-cycle engine and modified it for use in their Skycruiser light trike. Although the trike is too fast for Part 103, it does make weight. Climb rate is 550 fpm, comparable to the North Wing Maverick with the Verner engine. The engine and re-drive weigh 75 pounds. Price is about $4,600 plus about $500 shipping. Bautek’s Harald Zimmer reports that they have three years’ experience with no problems. TBO is 1,000 hours, but Zimmer says that Bautek has 25,000 hours on one of the engines that they’re using to power a pump. It still runs well, having had only spark plug and oil changes.
 
Bautek/Briggs & Stratton 38hp
Bautek has also begun shipping a 50hp B&S engine, similarly souped up, but with a Hirth geared re-drive. About $8,000.
Rotary Engines
Rotary (Wankel) engines have been a great disappointment. They would seem to be a natural fit for aircraft use—lightweight, high power, and smooth running. But no one has yet gotten them to work reliably in airplanes. In 2005 or thereabouts, the people who owned the Phantom ultralight experimented with rotaries. They ran into heating problems that they could not overcome. Reports Kamron Blevins of North Wing, “I had a mechanic who had two of them. The engine had too much torque and ripped the cogs right off the belt within half an hour after putting a prop on it.†Paul Mather at M-Squared had the same problem in 2009. Pressing on, he told the EAA’s Sport Pilot magazine that he overcame that problem with a different belt setup. But he subsequently abandoned rotaries —due to bearing problems I hear tell.
Most recently, paramotor vendor Parajet has offered two rotary engines, a 25hp and a 40hp model. Our own Michael O’Daniel had one of these at the Airpark last year. He found it amazingly powerful and smooth, but a little too heavy for backpack use. He thought it would be a good fit for a paramotor used with a cart. However, Terry Raber reports that he has been unable to get the Parajet people to reply to his inquiries about using the engines in his Aerolite 103. He thinks they’re going after the UAV market. Contrary to what you might think, this is not good news. Says Terry, “If so, it means that they’re not focused on my industry and that they’ll probably over-price it. I have seen other cases where people go for the high price up front, sell a few, and go bust. As a manufacturer, I have to be very aware of the parts availability.†But at least the Parajet rotaries are not ripping up their re-drive belts. That’s progress of a sort, so maybe something will come of them yet.
 
Electric Motors
We all hope that the billions of dollars invested in battery research by the auto industry will succeed, since the battery is the main limitation. As things stand today, you can buy an electric trike (the ElectraFlyer) for $19,000 that has an 18hp motor and a two-hour flight duration at, I’m guessing, about 25mph. Designer Randall Fishman is moving next into highly-streamlined airplanes. These will deliver more performance, but not necessarily more battery life. That depends on battery development (or, perhaps, on super-capacitor development) outside our industry.
ElectraFlyer. 18hp, 25mph cruise, 2 hour duration, 247 lbs.
All of us have heard of Yuneec, the Chinese manufacturer of radio-controlled aircraft that has burst on the scene. But Terry Raber, the Aerolite 103 maker, says that the engines from Yuneec are not really available yet.
Yuneec e-Spyder. 27hp motor, 37mph cruise, 1 hour duration, 253 lbs.
We all are watching electric motor developments with excitement. But it’s clear that electrics are not yet a replacement for the Rotax 447 and 503. Sooner or later, maybe; but not yet.
* * *

 

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Posted

A bit heavy but the HKS is a GREAT engine with a SOLID company behind it. Fits nicely in as a 503 replacement.

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Posted

Rotax is manufacturing another small motor currently in the sleds that I (and many other guys i know) think could show promise. The Ace 600 4-stroke motor. Very light weight and a favorable power and especially torque curve. 60hp in a sled, derate it and drop the injection for a carb and it could easily do the 40-50 hp needed.

http://www.ski-doo.com/technologies/engine-technologies/4-strokes

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Posted

That new Ski-doo engine looks sweet!! How could this be fitted to our application. I would like to have the 900 model in my Zenith 701.

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Posted (edited)

I hear that there is a guy in Alaska working up an Artic Cat 800 something engine with redrive - if he can get it going, it may be a high-horsepower winner for the 2-stroke drivers.  It should get your 701 off the ground quickly!

EDMO

Edited by Ed In Missouri

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Posted

The new Sport Pilot thing recked the need for the 447 & the 503. It knocked alot of people out of aviation.

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Posted

The new Sport Pilot thing recked the need for the 447 & the 503. It knocked alot of people out of aviation.

Wonder if that was an unintended consequence or the plan all along?? Jim Chuk

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Posted

I can name off a couple dozen guys in my EAA chapter alone that Sport Pilot brought into aviation.  They didn't want to fly 'unsafe' ultralights and couldn't afford Private Pilot and the associated certified spam cans.  

 

Sorry, Mark I don't buy that SP knocked more people out of aviation than it brought in.  It brought me back into flying.

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Posted

Some of us old codgers wouldn't be flying without the SP rating - After I turned 50 I had a doctor fail me on my medical because "I had never been deferred" because of a heart murmer I had since I was 7 years old - took me a year to get reinstated - passed two more physicals after that - wont do medical anymore!

EDMO

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Posted

When I started flying, in my area there were a LOT of fat ultralights and a LOT of people flying them. The airport was full of activity and there was someone to fly with almost any time of the year. The airport was very alive and vibrant. When the SP rule was passed only a couple of the folks flying the fat ultralights went on to get their SP cert. The rest stopped flying. Since the small experimental/fat ultralight activity was the most visible and active groupe on the airport, the airport personality has changed dramatically. There is much less going on. I think it is sad. I don't know what to blame it on other than overregulation.

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Posted (edited)

Also keep in mind that since the LS became available our country's economy has gone down the schmidt chute thanks to the abominable lack of leadership in the White House. This has more than a little to do with slowdowns at our little airports.

I'm sorry to hear of the fat ultralight crowd to scared or whatever to follow up and regain legality. They were in violation before why not take the opportunity to step into the light and enjoy 'legal' flying. Many of these folks were just too plane (sic) lazy to take the step and become certified. I know several like that too. It's a shame, really. Part 103 was and IMO still is dying. I don't see much of a future other than a very few diehard enthusiasts. LS didn't start that process, but it probably is hastening the demise.

My airport has been very fortunate to have a very active LS instructor and community surrounding our EAA Chapter. It's what is keeping our airport afloat.

Edited by Av8r3400

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Posted

"Many of these folks were just too plane (sic) lazy to take the step and become certified."

That certainly was the case at our airport. Too lazy or scared or just didn't want all of the work that goes along with regulation. I sure don't blame some of them though. There really is a lot of excess crap to slog through to stay truly "legal" in every respect.

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Posted

My Dad fell into that group. Larry in the beginning depending on what you were flying and your location, it was VERY difficult to get a SP license. My Dad had to go all the way from Central Idaho to Salt Lake City to get his checkride and that was AFTER him having to train with a guy who he had 50 times more experience than. The whole process cost him a fortune. He had been flying his 2 place Powered Parachute for over 10 years as a certified instructor under the instructional use only exemption and overnight he became illegal to fly anymore without his SP ticket. He went through the hassle to get it but after he couldn't give instruction anymore he hung it up and quit flying too. It was sad as to see.

 

I agree that SP benefited a lot of folks but the vast majority it seems were all guys who were previously flying big fast airplanes and had 100 grand to blow on an LSA. All the guys flying two place quicksilvers, autogyros, PPC's, and other true homebuilts (the guys who really make a small airport a pleasant place to hang out) seem to have dwindled while the RV12, Rans, Skycatcher, etc (the guys who need a glass cockpit, leather interior, and autopilots) types have thrived.

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Posted

I know of 4 sport pilots in my immediate area. Three of us were flying ultralights, one of which was a gyrocopter. I was able to take the written, oral, and flight tests because I was already a licensed UL pilot. I actually was the second Sport pilot in Mn. The other three guys trained with a CFI that had a champ and got their tickets that way. I don't know of any other guys in northern Mn that are SPs but there may be some. I think we all would have been happy if the FAA would have relaxed some of the part 103 rules (especially weight) but such was not the case. I think we had lots of fun when we were flying our ultralights, like one of my flying buddys says, now we just fly in bigger circles. And for more money I might add! Jim Chuk

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Posted

There's a ton I wrote here, but I deleted it.  We'll have to just disagree.

 

I think that the LS rating is a good thing.

 

I think that the 'fat' 103 thing was not.

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Posted

Don't get me wrong, I'm glad I have the SP lic. It would have been much harder to get a private ticket. Also, it's nice to take someone else with. But I think the fact remains, that ULs have taken a big hit. Jim

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Posted

There lots of us older pilots who had private and commercial certificates that cannot bear the high costs of tests to prove we are not going to pass out or have a heart attack while flying our little birds - We have flown our Champs, Pipers, Ercoupes, whatevers, for 40 to 60 years - but we cant take the chance of one stupid medical doctor grounding us now

- If we are safe enough to drive to the airport, and we feel able to fly, then the SP is the best thing that ever happened for us.

For those too lazy to put in the effort and money it takes for a SP or Private certificate:  I guess they just don't want to fly as badly as I do.

That's my last 2 cents worth on this issue.

EDMO

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Posted

Interesting discusion.  I welcomed the SP rule when it came in and gladly went from flying as a PP to flying under SP rules without having to continually renew my medical.  It just so happened that I already had a SP legal plane so life was good for me, but I was not really aware of the hassle and cost this had on the part 103 crowd.  I sure hate that SP could not have happened and still leave the ultralight class alone.  Seems like Gov regulators cannot stand to do anything unless it negatively impacts sombody.

 

Oh, except we know Obamacare would never do that....

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Posted

But the point is, that SP doesn't impact 103 operations or the true ultralights.  That was already dying on its own.

 

What it did was kill off the "Fat", two seat "ultralights" that were operating in, at best, a gray area and at worst totally black (unsafe) loophole in the 103 regs.  Allowing anyone and their dog to get an "instructor" permit, fly a two seat, heavier plane and take passengers posing as "students".   For every one "legitimate" ultralight instructor (like Joey's dad), there were ten that had the permit only to fly passengers.  The FAA was taking notice.

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