Unbiased look at AeroVee 2.1?

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NCPilot

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So I'm considering the Sonex as an aircraft for me to build and I'm also considering the AeroVee 2.1 engine with the AeroInjector. However I've always heard nay-sayers talk about auto conversion engines and I'm wondering if I can get an unbiased look at the AeroVee 2.1 engine, I want the good, the bad and the ugly.
 

djschwartz

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The reason you can't get an "unbiased" evaluation of these types of engines is that there is no "independent" evaluator of them. Nor have any of them built built and flow in large enough numbers and for large enough numbers of hours for there to be real history on which to evaluate them. You're pretty much stuck with the opinions of the promoters and skeptics which will obviously be either overly optimistic or overly pessimistic. The best you can do is get as much as you can from both and then learn enough about engine design and construction to make a decision for yourself. No matter what you do, any such relatively uncommon engine with limited support is going to be more of an unknown than one of the well known standard aircraft engines. That doesn't make them bad; but, it is a part of your project decision making that you must accept.

And in general, I'd say that my experience in over 40 years of homebuilt aviation has been that the over optimism of the promoters is greater than the over pessimism of the skeptics.

Dave
 

Topaz

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And there you have the "negative" viewpoint. Sorry, Dave, but you should announce that you're firmly in the "skeptics" camp.

NCPilot, there's only one "unbiased" view out there - the people that own and fly behind these engines. You should be able to find and contact owners of various AeroVee-powered projects, possibly through Sonex, and simply ask them: "How's it working out for you? How much time do you have on your engine? What problems have you encountered and would you do the same thing again?"

Those are the questions you really want answered, right? So go straight to the horse's mouth.

I'm something of an optimist with regard to auto-conversions. I'll freely admit that. I know that these engines certainly have their limitations and, like any machine, you can't ask them to do more than they have been built to do or bad things happen. We had a guy here once whose friend installed a VW conversion of a displacement that's really only reliable up to about 65hp in an airplane that required a minimum of 80hp. Then he "hot rodded" the motor to make close to 80hp when it proved that the airplane was nearly unflyable with 65hp, just like the kit manufacturer said in the first place.Then he claimed "VW engines are junk" when the thing burned up and failed. Can you really blame the motor when someone abuses it like that? But small, light airplanes have been flying behind VW conversions since the '60's. You certainly don't hear about them falling from the sky in droves, and they've been extremely popular in the periods where smaller airplanes were more common. Literally thousands of airplanes have flown behind VW conversions. These days, homebuilts tend to be larger and faster (RV-10, etc.), and small motors like the VW series aren't as common.

But, used within their limits, it's a motor. It turns a prop and your airplane moves along. There's nothing magical about FAA certification - it's just a series of tests. An engine that hasn't had those tests may not pass them. Or it might pass them with flying colors. But at the end of the day, an engine is an engine is an engine, and the only test that really matters is hanging one off the firewall and spinning a prop with it.

As far as the AeroVee goes specifically, everything I hear says that they're good little motors, if you respect their limitations and put them in a light, small airplane. Since the Sonex was designed for that engine, it's the perfect candidate for having a good experience with one. Build the airplane to the plans/kit, and don't expect anything more out of it than the nice little very-light two-seater that it is. Oil it when they say to, and overhaul it when they say to. VW's don't get 2000h TBO's - more like 1200h. That's not a bad thing, it's just a number. And when you look at the price of VW parts compared to the price of Lycoming or Continental parts, you'll still have a much lower lifetime cost than the certificated motor, even with the shorter TBO. I like Great Plains VW conversions as well, and they have an even longer history in business. If these motors were really the junk that some of the skeptics would have you believe, do you really think GP would've stayed in business over thirty years?

But like I said - I have a bias here, and I'm not the guy who can give you the answer you really want. Go talk to some Sonex owners who have been flying for a while. They'll give you the real story.

Good luck!
 
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djschwartz

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And there you have the "negative" viewpoint. Sorry, Dave, but you should announce that you're firmly in the "skeptics" camp.

NCPilot, there's only one "unbiased" view out there - the people that own and fly behind these engines. You should be able to find and contact owners of various AeroVee-powered projects, possibly through Sonex, and simply ask them: "How's it working out for you? How much time do you have on your engine? What problems have you encountered and would you do the same thing again?"
Actually, you seem to be of the camp that if you're not an enthusiastic supporter then you're a completely unaccepting skeptic, that there's nothing in between. I am not firmly in the skeptics camp. I just don't buy all the hype that goes around from the promoters. I've seen too much of it for too many years and seen a lot of folks end up disappointed in the end because they thought they were getting a lot more than what they ended up with.

I never said it I thought it was a bad engine or a bad idea to use one. I just think, and I stand by the opinion, that uncommon engines, including and especially auto conversions which remain uncommon compared to standard engines, are a less certain quantity and more of a project than one of the standard engines. One needs to be a more educated buyer and to have reasonable expectations in order to have a good experience with one of these. If you do that, then it might very well be the right thing for you to do.

Dave
 

autoreply

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I'm firmly in the "anti-car" camp. They can be made to work, but very few are actually properly engineered out, far fewer have sufficient hours behind them to be certain they're solid.

The VW (and the Take-Off BMW conversions) are the only exceptions I can think of.
Thousands have flown in certified planes and still do. They're a disaster in the higher HP ratings... not surprising given their inherent limitations.
I still wouldn't fly one, unless a few hundred engines of that exact layout are flying. The Aerovee's, the "common" ones from Great Plains, hearsay also Revmaster and several of the certified ones (as expensive as a Rotax) easily qualify there.

If you can live with the limitations (less power, more weight, FAR less static thrust and thus longer TO) as the Rotax 912S; go for it. 13K US$ less cost is the other side of the equation ;-)
 

Brian Clayton

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Monday, I talked to a pilot/owner in west palm beach....in person....while looking at the plane..... about his 80hp VW in his 2 place Kitfox. He pulled a 582 rotax and replaced it with the VW. I simply asked him how he liked it. Flys fine. Its slow. Doesn't have a abundance of power. Only had single ignition, so he didn't want to fly it down to the Bahamas (uneasy flying it over water). Liked it better than the 582 because he didn't mix fuel, replace plugs as often and it sounded better. He was fixing a minor oil leak on something while I was there. Him and his partners bore holes in the sky all over south florida with it. Overall, he is pleased with it. He UNDERSTANDS the LIMITATIONS of what he has and is happy with the performance the 80 hp vw in his plane gives him. The guy I bought my hirth 2stroke from in Tennessee has a sonex with a 80 hp vw. When I asked him a while back about it: He likes it. Pleased with the performance. Would buy another. Same guy has had a taylorcraft, several ULs with 2 strokes and 4 strokes and has flown a lot of basic airplanes (172 and down). I would say he has plenty of other experience to draw from to form a opinion, and he seemed to be pleased with the vw. I have no opinion personally, since I have only personally flown behind a 0-235 for 45 minutes in one airplane (rides don't count :)), but those are two people that I have met personally and recently, are currently flying 80 hp VWs and are happy with what they have.
 

NCPilot

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What I want to know is how well it'll do on a hot and humid day. I live in North Carolina and I'm wondering how it'd do in the middle of Summer. Right now I fly out of airports that have nice long and wide runways, but once in awhile I may get the crazy idea to land at a grass strip and I'd like to get out again. :p
 

Brian Clayton

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What I want to know is how well it'll do on a hot and humid day. I live in North Carolina and I'm wondering how it'd do in the middle of Summer. Right now I fly out of airports that have nice long and wide runways, but once in awhile I may get the crazy idea to land at a grass strip and I'd like to get out again. :p
The one guy lived and flew in South Florida. It didn't seem to bother him unless he was loaded down. Didn't stop him, he just backed further up the grass runway they have at his airport. Don't remember how long the strip was, X05 I think. Indian town, florida.
 

djschwartz

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What I want to know is how well it'll do on a hot and humid day. I live in North Carolina and I'm wondering how it'd do in the middle of Summer. Right now I fly out of airports that have nice long and wide runways, but once in awhile I may get the crazy idea to land at a grass strip and I'd like to get out again. :p
Am I correct that the real issue you're concerned with is not the grass but the relative shortness of the runways and possible obstacles to clear? We have a fellow who flies a Sonex off the grass at our strip but it's 3200 feet long and near sea level. It has a clear departure to the north and some trees to the south that are tall but about 1/4 mile from the end of the runway. The Sonex does not appear to be any rocket ship when it comes to takeoff roll and climb but it is adequate for this field. I believe he has a Jabiru in his. I would not operate the tri-gear version of the Sonex off grass. There was one of those here also and the nose gear folded while taxiing in the grass. That took out the prop, induction system, and lower cowl. I never heard whether the engine lower end was OK or not.

Any engine that is direct drive and needs to turn up to get get power is going to result in the use of a propeller that is less efficient for takeoff acceleration and initial climb. Such a prop may actually be more efficient for cruise but that remains to be seen and is a function of how well it is designed and matched to the specific aircraft and engine. That said, I don't think the Sonex has the ground clearance for anything other than a relatively short diameter prop.
 

Topaz

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...One needs to be a more educated buyer and to have reasonable expectations in order to have a good experience with one of these. If you do that, then it might very well be the right thing for you to do.
Which, I believe, is precisely what I said as well. No more, no less.

...and seen a lot of folks end up disappointed in the end because they thought they were getting a lot more than what they ended up with.
Don't you think that might have as much or more to do with unrealistic expectations than any actual limitation in the motors themselves? The example I gave earlier was a classic one - guy buys a smallish VW "on the cheap", and then tries to get it to do something that it was never intended to do. Then complains that the motor was at fault in some way. That situation was rampant in the KR-2 community, where builders couldn't seem to finish one that wasn't 200+ pounds overweight empty, and then complained when the airplane wouldn't fly very well on the original-sized motor with the full "spec" useful load. The guys would run WOT all the time, burn up the motor, blame the motor, and then put a much more powerful Corvair or O-200 into the overweight plane and rave about "how much better an engine this is than that VW piece-of-junk!"

I'm having a hard time seeing how that's the motor's fault.
 

Pops

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I have flown over 85 different aircraft in the last 45 years, so I have a little experience behind different engines. Built a KR-2 in the late 70's and at this time flying behind my 3 rd aero VW engine that I have built.( built VW engines in the 70's as a side business). Have a 1835 cc VW engine in my little single place Super Cub. First, I would never put a VW in any 2 place aircraft. Its going to be marginal with 2 people, in any 2 place airplane built for a VW. ( I think the best 2 place VW engine powered airplane would be the Cygnet SF-2A). Don't put a VW engine in any airframe that you need over about 55 continuous HP. I think the ideal VW engine size for reliablity/power would be the 1835-1914 cc and also the most HP for the money. IF I were going to buy a VW engine my first choice would be a Revmaster but like the Aero-Vee, you can't hand prop it. So that leaves the Revmaster and Aero-Vee out for me. Also a big negative for the Aero-Vee is the carb. The Zenith carb from Great Plains is a much better carb. Try using the Zenith carb if you don't believe me. So, for me it would be an engine from Great Plains, and if I am not comfortable assembling a engine that would be a another negative for the Aero-Vee ( the Revmaster is assembled) and you can get the engine assembled by Great Plains for a small fee.
At this time, my 1835 VW engine is single ignition with a Slick mag. I have another set of single port heads that I am drilling for dual ignition with a CDI in the engine dist location. Since I have no electrial system I plan on using the 7 amp gell cell battery that I power a handheld radio for the CDI for take-off and landing and a small solar panel . I use straight weight 30 oil and change the oil every 25 hrs and check and record the valve lash for a trend. Cruise RPM is 2650, that is about 60%.
I have a friend that has over 1000 hrs in a 37 HP,1/2 VW in a Mini-Max.
Great engine IF used in the correct airframe. Dan
 

Kyle Boatright

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Actually, you seem to be of the camp that if you're not an enthusiastic supporter then you're a completely unaccepting skeptic, that there's nothing in between. I am not firmly in the skeptics camp. I just don't buy all the hype that goes around from the promoters. I've seen too much of it for too many years and seen a lot of folks end up disappointed in the end because they thought they were getting a lot more than what they ended up with.

I never said it I thought it was a bad engine or a bad idea to use one. I just think, and I stand by the opinion, that uncommon engines, including and especially auto conversions which remain uncommon compared to standard engines, are a less certain quantity and more of a project than one of the standard engines. One needs to be a more educated buyer and to have reasonable expectations in order to have a good experience with one of these. If you do that, then it might very well be the right thing for you to do.

Dave
Apologies for no spaces between paragraphs. A couple of sites are that way for me...
Did the owner offer any data or hard facts? "I like it." is hard to evaluate. "I've got 250 trouble free hours on it." is a datapoint. Also, one thing I see with owners (not just airplane owners) is that whatever they have is "great, outstanding, love it" until they sell it, and the story changes. People have confirmation bias - I bought it, I buy good stuff (make good decisions), so whatever I built or bought must be good. Even when it isn't. Count me as a douber on the VW conversion for anything that needs >55-60 hp. Which pretty much means any 2 place airplane.
 

saini flyer

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An engine is an engine.... Forget about where it came from.... just look at the application it will be used for and then evaluate!
You want a safe and reliable engine first because you want to fly more than once PERIOD

For VW conversion for aircraft, The bigger picture is indeed the airframe these are attached to (the application) to get you the expected results. Mix and match and the results will be mixed too!!
Some numbers for you on VW conversion for Aero use from April 2010 Kitplanes magazine:
AeroVee 2.1 - 463 engines
Great Plains Aircraft (all types) - 2023+
Hummel - 400+
Revmaster - 3378

You tell me if this is a flawed engine for aircraft useage, how someone can run a business around it for 30 years and counting?

Off Topic: Jarno, that takeoff BMW just looks like such an incredible setup. I like what I read about it so far. Thanks for bringing it to my attention. I agree, it is the only one besides VW that should be on the list :)
 

Vipor_GG

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I don't have any experience with any airplane engines yet, but plan to use a VW to power a Super Koala for my first plane. I lived in Florida for 10 years and saw many VW powered airboats that were run hard with no reliability issues to convince me they are reliable. As for power, if a 503 Rotax will pull it along a 65HP VW shouldn't have a problem.
 

Vigilant1

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What I want to know is how well it'll do on a hot and humid day. I live in North Carolina and I'm wondering how it'd do in the middle of Summer. Right now I fly out of airports that have nice long and wide runways, but once in awhile I may get the crazy idea to land at a grass strip and I'd like to get out again. :p
I fly behind an Aerovee in a Sonex. I flew it at max gross (1150 lbs--50 lbs above the Sonex recommended weight, but exactly the weight in this plane's allowed specs). It was a hot day (95 degrees) and as I recall the plane got off the pavement in about 1000 ft. The climb rate was not eye-watering, but it was certainly safe (better than a C-152 at max gross). Lots of people fly their VW powered Sonexes and Waiexes off of the grass--a taildragger and slightly larger tires are preferred by many folks who do it a lot, and if the strip is short, then it's probably prudent to fly solo. If true bush-flying is what you are after, then a different airframe might be something to consider.

I am enjoying flying behind the Aerovee. There are advantages to each of the approaches of the major VW aircraft engine suppliers (Aerovee, Great Planes, Revmaster, and Hummel). The good news is that there are TONS of each flying, which means there are a lot of people who can tell you about them.
 

NCPilot

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I fly behind an Aerovee in a Sonex. I flew it at max gross (1150 lbs--50 lbs above the Sonex recommended weight, but exactly the weight in this plane's allowed specs). It was a hot day (95 degrees) and as I recall the plane got off the pavement in about 1000 ft. The climb rate was not eye-watering, but it was certainly safe (better than a C-152 at max gross). Lots of people fly their VW powered Sonexes and Waiexes off of the grass--a taildragger and slightly larger tires are preferred by many folks who do it a lot, and if the strip is short, then it's probably prudent to fly solo. If true bush-flying is what you are after, then a different airframe might be something to consider.

I am enjoying flying behind the Aerovee. There are advantages to each of the approaches of the major VW aircraft engine suppliers (Aerovee, Great Planes, Revmaster, and Hummel). The good news is that there are TONS of each flying, which means there are a lot of people who can tell you about them.
Well I'm not looking for true bush flying, I'm considering the Sonex with the AeroVee because I'm a sport pilot just looking for a LSA that's fun to fly, easy to build and easy to maintain. I fly by myself 98% of the time. I asked about grass strip because I may want to fly into some of the local grass strips that's around here, just for ****s and giggles.
 

skier

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Count me as a douber on the VW conversion for anything that needs >55-60 hp. Which pretty much means any 2 place airplane.
I just want to point out that you can design a great 2 seat airplane to fly behind 65hp (or less). Just look at the J-3. The Aeronca C-3 would be another one to look at, but I believe performance is marginal in that aircraft(36hp?). There's also the Quickie Q-2 with a 64hp revmaster.

It's all about expectations. You aren't going to get Lancair 320 performance with 2 seats on 65 hp, but you can get a decent, flyable, and safe aircraft.
 

Vigilant1

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Well I'm not looking for true bush flying, I'm considering the Sonex with the AeroVee because I'm a sport pilot just looking for a LSA that's fun to fly, easy to build and easy to maintain. I fly by myself 98% of the time. I asked about grass strip because I may want to fly into some of the local grass strips that's around here, just for ****s and giggles.
Then you'll like the Sonex. There are hundreds flying, most of them on 80 HP. Performance is more "energetic" with the 120HP Jabiru 3300, but 80 HP is enough to have a lot of fun. The Aerovee is reliable and it's cheap to maintain and to feed.
 

NCPilot

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Then you'll like the Sonex. There are hundreds flying, most of them on 80 HP. Performance is more "energetic" with the 120HP Jabiru 3300, but 80 HP is enough to have a lot of fun. The Aerovee is reliable and it's cheap to maintain and to feed.
Awesome, I do plan on building the tailwheel version of the Sonex, simply because I do have plans to fly into grass strips from time to time, and tailwheel are better for that kind of operations.
 

Kyle Boatright

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I just want to point out that you can design a great 2 seat airplane to fly behind 65hp (or less). Just look at the J-3. The Aeronca C-3 would be another one to look at, but I believe performance is marginal in that aircraft(36hp?). There's also the Quickie Q-2 with a 64hp revmaster.
You're absolutely right, but the A-40, A-65, and Aeronca E-113 made power at 2500 rpm or less. Not 3,000+. The difference in prop diameter really matters at low speed.
 
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