What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

The No Alternative section

rv7charlie

Well Known Member
I find it fascinating (euphemistically speaking) that every time someone mentions anything other than a Lyc on this *alternative engines* page, there's a flurry of activity from Lyc users relating the one instance of something they heard about that makes whatever product mentioned the very thing that will cause a rapid slow death for everyone in a 10 mile radius.

If us alt engine guys did this every time there was a Lyc failure, you wouldn't be able to find anything else on the Lyc page.

Anecdotes do not define a product. I've got my own story about Franklin, too. But the months spent trying to get it working correctly were caused by using incorrect parts in the overhaul (by an A&P); not by the engine itself.

Want to hear a few Lyc stories? Are you willing to assign the same weight (condemning the entire product line) to those stories that you assign to all the 'alternative' products? If so, you need to find a new hobby, 'cause flying a Lyc will kill you quick.

Charlie
 
I sure know a lot of pilots in the backcountry... being pulled along by Franklins. Been doing it for years.
 
No lyc

Show me a cost effective alternative to a Lycoming or Continental that's proven itself FLYING ( not on a test cell ) for 1000 hrs .... I'm all ears .

Maybe if I was building a plane to "Tinker " with and never fly it out of the pattern I would be interested in some alternative power plant , but I'm like 99% of Vans customers who want a reliable cross country aircraft .
 
I for one am glad there are people willing to experiment and push the boundaries. It's 'Experimental Amateur Built', not 'Bone stock plug-and-play Amateur Built'. As long as people are understanding of the risks and the amount of time and effort required, good on ya. Reliability statistics aren't everything, and I'd venture to say that not many advances in aviation were extremely reliable at first.

Chris
 
Flying a Lyc powered -4; building a Mazda Renesis powered -7. The Franklin reference was to a liaison a/c restored by the local CAF chapter.

I've got 25 years of experience with failed mags, carbs, cylinders, etc on Lycs, with virtually zero failures in automotive engines during that time. And don't give me that bull about Lycs being designed to run at full power all the time. They just aren't. They are designed to have a power rating that's about 1/2 to 1/3 what the core could produce (at a lifespan that couldn't come close to being called 'reliable').

The point of the thread is that this is the *alternative engines section*. Most of us actually involved in alternative engines realize that they are almost always one-off projects that will require tinkering, and that they haven't had the decades of proving that Lycs have had. You aren't telling us anything we don't already know. It baffles me that so many people are so fixated on telling everyone else that they must not be different from them. What's the problem; no confidence in your position? Afraid that if someone tries something different you'll discover that you were wrong?

If we alt engine guys spent as much time running down Lycs as you Lyc guys spend calling us idiots, we'd get 'moderated' off the forum for uncivil behavior. (hint...hint) [ed. Only those not following the posting rules get 'moderated off'. By me. <g>, dr]
 
Last edited by a moderator:
The great thing about this sport, hobby, obsession, or affliction (depending on your personal point of view) is that we enjoy the freedom to, well, experiment should we be so inclined.

I've never understood the need apparently to convince others that a partiular path is "right" and therefore that other choices are "wrong".

C'est la vie.

I like my Lycoming because I got it for a good price and was able to overhaul it myself. Chose not to buy a new one not because it was a bad idea but because I couldn't afford it at the time.

To each his own. Personally I wish my airplane a a Merlin or a P&W engine in it. But a Lycoming or a Briggs and Stratton suite me fine as long as it flies. That is what is important.

These RVs have gotten so advanced we've run out of things to talk about wrt building them.
 
I've noticed similar thread drifting whenever the primary topic is either "weight reduction/control" or "my alternator is less than 40 amps with no secondary alternator".
 
And don't give me that bull about Lycs being designed to run at full power all the time. They just aren't. They are designed to have a power rating that's about 1/2 to 1/3 what the core could produce (at a lifespan that couldn't come close to being called 'reliable').

I don't think you are doing your point any favors by trying to disparage the traditional engines as poorly designed. The idea that a naturally aspirated 360 cubic inch engine (5.8L) could produce 600 HP at 2,700 RPM reliably and afford-ably is pretty aggressive. That's just over 100 HP per liter, something naturally aspirated street cars only achieved first in about the year 2000 (and at 8,000+ RPM).

At 2,700 RPM, that would be a BMEP of 490 PSI, well over 2X the BMEP that a Nascar or F1 engine runs at, and deep into the territory of never been done.

The goal of an aircraft engine is not HP per liter. It's a combination of size, weight, fuel efficiency, reliability, and of course the ability to turn a propeller at subsonic speeds.

You'll do better advancing the "alternative" engine world by finding a proving a design that can actually put out the power and reliability you state a Lyc engine doesn't have rather than just stating it doesn't.
 
Last edited:
Lots of good points here. I own a Lyc and a Continental, and prefer the Continental over the Lycoming, for a number of reasons. There's internecine warfare even in the certified engine world! :)

With my biases clearly stated above, I believe the builders who choose to install an alternative engine are indeed experimenters; for that, I take my hat off to them.

I truly feel sorry for the numbers of builders who bought an alternative engine package from a vendor who essentially sold the package as though it were a well-engineered, proven design, when in fact it was little more than a lab rat waiting to die a premature death. Some of these vendors have done the alternative engine movement a tremendous disservice, not to mention the reckless and irresponsible imperilment of their paying customers. Many of those vendors have gone the way of the Dodo. Good riddance. Some of them are still around, having shifted to other projects. To their potential customers, caveat emptor would be the understatement of the day.

At our field we have a Mazda rotary-powered aircraft which has experienced its trials and tribulations. The builder is indeed a man of towering patience.

Similarly, our EAA chapter president is very close to first flight in his canard pusher airplane, powered by an alternative engine. When I see the efforts he has gone through to make his core engine and its supporting systems safe and reliable I feel honored to be even loosely associated with the breed of people who work so hard to put the "E" in EAA.
 
with virtually zero failures in automotive engines during that time.

Flying exactly on what kind of airplane?

I have stacks of books and loads of information on people trying to make use of alternative engine and there was a time no one could talk me out of trying
one of those.
None of the promoters ever to the best of my knowledge has ever succeeded in the long run without significant risk and cost in achieving "fright" time much beyond a few hundred hours.

The Franklin is probably the best of the "alternative engine" choices but still
needs considerable engineering to make it work in an RV.

I am always interested to hear of success but promoting false hope based on
wishful thinking is not advancing your cause.
 
Old Engines

Personally, and as a new entrant to the EAB world, I find it disheartening that nobody produces a new technology aviation engine that can compete on price / performance with these ancient Lycoming / Continental engines. These basic designs have been around a long time, and given good service but they've been around too long in my opinion. Proven technology is one thing but, in this day and age, I have to think we can design and build a better aviation engine. Yeah, I know, it's all about liability and certification. I wonder though, is this really the BEST engine that we have the technology to build, or simply the engine that we have the will to push through the bureaucratic process?

Hmmm, maybe I need to start a new engine company!
 
Arguably, Rotax has succeeded at creating a new aircraft engine with price and performance in line with other engines. They just focused on the 100HP range, not the 150-200 HP range we like. They even have full digital FADEC engines.

What they have proven in a sense is that you can't really increase power, decease fuel burn, decrease weight, or decease price a lot.
 
...
I truly feel sorry for the numbers of builders who bought an alternative engine package from a vendor who essentially sold the package as though it were a well-engineered, proven design, when in fact it was little more than a lab rat waiting to die a premature death. Some of these vendors have done the alternative engine movement a tremendous disservice, not to mention the reckless and irresponsible imperilment of their paying customers. Many of those vendors have gone the way of the Dodo. Good riddance. Some of them are still around, having shifted to other projects. To their potential customers, caveat emptor would be the understatement of the day....
That is exactly why I struggle with alternative engines. There have been engine builders out there promising the world and delivering a small rock. Then the builder ends up buying a second engine, for which he probably doesn't have the money, after spending his engine fund on a failed experiment.

What I don't get is why do new engine designers always try to sell their unproven engines at the same price as Lycoming? If I were trying to get a new engine into the market, I would sell them at half the competitor's price until I had a proven product. Once a number of customers are successfully flying, then start jacking the price up. Until you have a proven product, don't bother me with your dreams and unproven designs.

The Franklin engine is a proven design. The four cylinder engines are not well regarded and the only reason I can think someone would put one on an airplane today is to keep an antique as "original" as possible. Their six cylinder engines, for which I have a number of hours behind are good engines but not well regarded because they are no longer in production (in the USofA).
 
UL power is coming along with a good recipe I believe but tend to have a similar somewhat arrogant attitude with regards to customer service support that Rotax does in some cases I've heard from some of their customers. That doesn't help either of these companies in my view. The price point though is the trouble with these- around $200/hp.

There is a new line of 2, 4 and 6 cylinder, opposed, air cooled, DD aero engines under development in the US at the moment designed to compete with the likes of Rotax, UL and Jabiru at a reduced price point. These will be non-certified to keep development costs down. The experimental world needs a US produced alternative to the imports I believe.That's about all I can say at this point and wish them luck.

As far as the auto conversions go, the most successful to date was the RAF 2000 Gyros powered by Subaru EJ engines. A group survey back in 2006 found about 125,000 flight hours collectively on the 600+ airframe fleet with few problems. The key was a good PSRU design, turning the same lightweight prop and reliable, cooling, fuel and electrical systems- duplicated over and over -the key to repeatable success IMO.

We have a fair number of one offs over 750 flight hours now, a few over 1000 and a few more over 1500 showing it can be done with proper design but no other large fleet of vendor engines has shown tens of thousands of successful flight hours to date that I'm aware of if that's what it takes to demonstrate reliability to the masses.

Talk's cheap, if you want to show the world, you actually have to show the world with several flying examples with many hundreds of trouble free hours each as a minimum. That won't come cheap or fast.
 
Last edited:
Alt eng

Value vs price . Let's assume a Lycoming cost $30,000 new ,after 2400 hrs (TBO ) it's still worth at least $8500 , that comes to about $9 per hour of use .
Say you can get a Franklin for $20,000, after the 1500 hrs (TBO ) what's it worth ? It's like the 2 stroke ultralight engines , not cheap per hour of use .
 
I find it funny that a Franklin (or PZL), a real aircraft engine line with millions of flight hours, is considered an "alternative" on this forum.
 
I don't think you are doing your point any favors by trying to disparage the traditional engines as poorly designed. The idea that a naturally aspirated 360 cubic inch engine (5.8L) could produce 600 HP at 2,700 RPM reliably and afford-ably is pretty aggressive. That's just over 100 HP per liter, something naturally aspirated street cars only achieved first in about the year 2000 (and at 8,000+ RPM).

At 2,700 RPM, that would be a BMEP of 490 PSI, well over 2X the BMEP that a Nascar or F1 engine runs at, and deep into the territory of never been done.

The goal of an aircraft engine is not HP per liter. It's a combination of size, weight, fuel efficiency, reliability, and of course the ability to turn a propeller at subsonic speeds.

You'll do better advancing the "alternative" engine world by finding a proving a design that can actually put out the power and reliability you state a Lyc engine doesn't have rather than just stating it doesn't.

I never said any of that stuff (except the 1/3 part :) ).

For the record, I do believe that Lycs are very good a/c engines. I'm just willing to look for something 'better'. Rutan (and others) did that, and we got the 1st privately funded trip to space.

You're setting limits that I'm not setting. Reno F1 regularly runs at far north of 4000 rpm and close to double the real world HP of a stock O-200. There's a former Reno biplane racer with an O-320 that operates north of 3600 rpm at airshows.

Point is, the core engine will produce *far* more power than Lyc rates it for. Their 'rated power' number is massively derated for precisely the reasons you specify.

Modern 6 liter automotive engines easily produce far north of 400 HP *continuously*, and in proving it, they do it with multiple engines, each in 500 hour continuous test sessions cycling between max torque and max HP, with repeated cycling of operating temperature coolant with near-freezing coolant pumped through the engine. (IIRC, the FAA mandate for a/c engine certification is less than 1/2 that time on a test stand, in far more benign conditions.) How long would one of those engines last, and how reliable would it be, if operated at roughly 1/2 it's rated HP for takeoff and 35-40% continuous (assuming proper execution of cooling, drive issues, etc)? Weight on the current crop (with redrive and cooling system) is very close to comparable HP a/c engines.

But the point of this thread remains: why can't the Lyc guys either be constructive or at least show us the same courtesy we show them? We know all their arguments, and most of us, at least, know which are valid and which are basically religion. The 1st guy to criticize in this thread has a sig line that says he's flying a 250 HP RV-8. Do any of the Lyc guys see the inconsistency(-ies) in his position? I certainly do.

Charlie
 
Rutan (and others) did that, and we got the 1st privately funded trip to space.

Very true!
He also spent decades before that thinking outside of the box with new aircraft designs that he built and flew, but with only a couple of exceptions, each one had a traditional aircraft engine (or engines) powering it.
 
That's easy to explain;
Rutan was into aerodynamic advancement. It's best to make changes incrementally, so traditional power would be the way to go.
People that develop power plants want well proven airframes.
 
Personally, and as a new entrant to the EAB world, I find it disheartening that nobody produces a new technology aviation engine that can compete on price / performance with these ancient Lycoming / Continental engines. These basic designs have been around a long time, and given good service but they've been around too long in my opinion. Proven technology is one thing but, in this day and age, I have to think we can design and build a better aviation engine. Yeah, I know, it's all about liability and certification. I wonder though, is this really the BEST engine that we have the technology to build, or simply the engine that we have the will to push through the bureaucratic process?

Hmmm, maybe I need to start a new engine company!

It's all about money.

In order for a new engine to succeed in the market (and by that, I mean capture a statistically significant portion of the market claimed by Lycomings and clones), I think it will need to meet three criteria.

First, installing the engine needs to be no more difficult than installing a Lycoming. This means the engine provider will probably have to provide a complete firewall-forward kit and good instructions. The parts will have to be standardized, and no engine-specific knowledge or "gearhead" experience should be required. Ideally, no tuning of any kind should take place; the ECU should be delivered with preset safe fuel maps. Anything starting with "go to the junkyard and find an engine" is right out. I don't have to be an A&P to install a new Lycoming on an RV (or really, to install the manufacturer-supported engine on any decent kit airplane). I shouldn't have to be a gearhead to install an auto-conversion package.

Second, the engine will have to be cost-competitive with a Lycoming install. That is, it doesn't have to necessarily be cheaper outright, but short- and long-term costs can't be too much greater than a traditional engine. Any additional engine-specific cost should carry a clear benefit in reliability, simplicity (operational or mechanical), maintainability, or efficiency.

Third, there needs to be a reasonable service history with real users and demonstrated reliability. This threshold will be different for each person, but some will never accept it no matter what.

The problem is that getting all of these things takes a lot of time (design, testing, waiting on the market), a whole lot of money (since you probably aren't going to be breaking even until you meet all three items and are producing in volume), and "early-adopter" users willing to overlook item 3 and probably also item 2 (unless you're willing to sell way below cost and lose even more money at first).

And that's just talking about engines for the homebuilt market. Certified is a whole new ballgame, where new technology doesn't have to overcome just user opinions, but regulatory impediments as well.
 
Last edited:
The problem is that getting all of these things takes a lot of time (design, testing, waiting on the market), a whole lot of money (since you probably aren't going to be breaking even until you meet all three items and are producing in volume), and "early-adopter" users willing to overlook item 3 and probably also item 2 (unless you're willing to sell way below cost and lose even more money at first).
And even then you will still get grief from the traditionalists.

- A Rotax 912 Owner.
 
Alternative

Want to read about RV's and alternative engines ? Use the search feature and go to the beginning of this , 9 pages going back to 2006 . Click on some of the engine links ( most are dead ) . Looking at the posts I gather the failed Subie (
(King of Alternatives) has left an awful taste in the RV / alternative group . Maybe that after taste has ruined it for the other upstarts that show up to Sun&Fun / Osh with the pretty painted engine , fancy display and far fetched claims of HP, fuel burn and TBO .
 
I find it fascinating (euphemistically speaking) that every time someone mentions anything other than a Lyc on this *alternative engines* page, there's a flurry of activity from Lyc users relating the one instance of something they heard about that makes whatever product mentioned the very thing that will cause a rapid slow death for everyone in a 10 mile radius.

If us alt engine guys did this every time there was a Lyc failure, you wouldn't be able to find anything else on the Lyc page.

Anecdotes do not define a product. I've got my own story about Franklin, too. But the months spent trying to get it working correctly were caused by using incorrect parts in the overhaul (by an A&P); not by the engine itself.

Want to hear a few Lyc stories? Are you willing to assign the same weight (condemning the entire product line) to those stories that you assign to all the 'alternative' products? If so, you need to find a new hobby, 'cause flying a Lyc will kill you quick.

Charlie

And this is precisely why I rarely post in here anymore. That, plus this attitude from the site owner:" I don’t fly in aircraft that have engines in them that they weren't designed for (i.e. car engines in RVs) ", make me feel less than welcome. I'll continue to enjoy my RV-6 with my (oh, the horror) Subaru 3.0 engine on it, and confine my information sharing to venues that aren't as openly hostile as Vans Airforce seems to be..........


[ed. When I was first getting into the hobby I had the good fortune to hang out with Tracy Crook for an afternoon in Waco while he worked on his Mazda powered RV-4. I remember thinking "this guy knows more about engines than I ever will." Still feel that way, but it's not my cup o tea.

You seem comfortable flying behind an engine I don't. Nothing openly hostile about that at all, and I wish you would feel more welcome here. It wasn't my intention to make you feel unwelcome - it was my intention to say what *I* feel comfortable flying behind in that piece.

I had a Lyc explode on me as a student and had to dead stick into a grass runway, if that helps. I'm scared of all engines...some more than others. dr]
 
Last edited by a moderator:
That's easy to explain;
Rutan was into aerodynamic advancement. It's best to make changes incrementally, so traditional power would be the way to go.
People that develop power plants want well proven airframes.

Exactly!

The reason some seem close minded regarding alternative power is that they know that 99.95% of home builders want both (well proven airframe and power plant). Many have been deceived by the enthusiasm of others that any newer technology alternate engine choice is going to be better than an antiquated Lycoming.

Time and time again I have seen people spend (a lot) of hard earned money, only to be burned and either dump the airplane at a huge loss, or spend a whole lot more to install a well proven power plant. Often times there was many people attempting to speak some wisdom to them regarding their decision process, but they chose to ignore it.

Experimenting is important. If none had done it we wouldn't have Lycoming engines (or be flying for that matter). Hopefully one day, one of those experimenters will come up with a proven reliable power plant installation that really is revolutionary, and that people can easily copy and then just go fly, but the reality is that no one has yet.

Side note: I find it interesting that anyone that is experimenting with an alternative engine considers realistic discussion and analysis of what is going on in the alt. engine world as being hostile. I would say that the majority of the time that is far from the case.
The reverse of that is the often exclaimed defense to look at the statistics "Lycomings have as bad of a record as alternative power plant installations. If you actually look at the data, that is far from true. I think others would embrace that part of our hobby much more if more of the people involved were as open about the failures as much as they are about the successes. I say "more", because some are open about it, but the majority are not. We end up hearing about the failures via aviation gossip. Then the defense is always... "you don't know the whole story". Well, don't be so secretive, so that we hear the facts instead of rumor.
 
Last edited:
Has Experimental Aviation Changed?

Last week I needed to replace my starter. I did not build my plane so it took some detective work. Automotive starter with a custom bracket, found a 15 year old receipt from an airboat starter company, great. They are still in business, and can sell me the starter, but some more Googling yielded a 25 year old magazine article (and a modern airboat thread) with some very interesting information. Conclusion -- a $50 automotive starter with some simple mods is perfect. It's now in service.

Reading the 25 year old reference, it seemed as though the spirit of experimental aviation has changed considerably over the years. It's true there were no 'comments' to see what the community at large thought of things, but the article conveyed real excitement about repurposing parts and fabricating solutions. Partially to save a few bucks, I'm sure, but largely for the joy of problem solving. It reminded me immediately of old-school hacker culture, or what I believe has been rebranded 'maker' culture.

Modern discussions on the starter seemed to congeal around the opinion that you really, really wanted to use a proper aircraft starter, and that it was no place to 'cheap out'. Get a Sky-Tec, get a B&C, etc. This surprises me, as the barriers to communication and sharing are so very much lower than they were 25 years ago, I would have expected the DIYers to be flourishing.

Maybe I'm wrong about the change of atmosphere, I'm fairly new to aviation and even newer to experimental aviation. I'm not (yet) a builder nor am I (yet?) a craftsman but I do find the DIY ethos extremely appealling.

So to wrap this rant up and bring it back to the subject at hand... keep on tinkering, alternative engine folks! This aviator approves, and I am certain that I am not alone.

-jon
 
Has Experimental Aviation Changed?

Yes it has.

It used to be an inexpensive way to get in the air, but often required a lot of tinkering to keep the airplane flying (fixing little stuff that broke, etc., because everyone was figuring out there own way to do things and some were better at it than others).

These days experimental aviation is more of a less expensive path to high performance, where people want to be able to just turn the key and go.
 
And this is precisely why I rarely post in here anymore. That, plus this attitude from the site owner:" I don?t fly in aircraft that have engines in them that they weren't designed for (i.e. car engines in RVs) ", make me feel less than welcome. I'll continue to enjoy my RV-6 with my (oh, the horror) Subaru 3.0 engine on it, and confine my information sharing to venues that aren't as openly hostile as Vans Airforce seems to be..........

Perhaps the world of RVs is somewhat self-selective toward the more common and well-proven engine designs.

RV airframes are a traditional design with specific cost/performance trades, well-proven, and (relatively) easy to assemble by the average homebuilder. Most of us who select the RV airframe for these reasons also base our engine choices on the same logic.

I would imagine that the more intrepid builders who really want to design and/or install an alternative engine configuration, might also be types that wish to have more involvement in the basic airframe design as well. Expecting to find an alternative engine section of the Vans forum equal in breadth to the myriad discussions on traditional engines may be disappointing, but consider the population in which you're looking.
 
Exactly!

The reason some seem close minded regarding alternative power is that they know that 99.95% of home builders want both (well proven airframe and power plant). Many have been deceived by the enthusiasm of others that any newer technology alternate engine choice is going to be better than an antiquated Lycoming.

Time and time again I have seen people spend (a lot) of hard earned money, only to be burned and either dump the airplane at a huge loss, or spend a whole lot more to install a well proven power plant. Often times there was many people attempting to speak some wisdom to them regarding their decision process, but they chose to ignore it.

<snip>

This is the aspect of alternative power plants I find discouraging. I enjoy squeezing a $ until it squeals so the realm of alternatives is attractive to me on several levels. But I hate to see a novice builder rushing headlong along an alternative path without significant research.

I have attempted to reason with such builders and help them explore the decision tree but once the Kool-Aid has been drunk further thought appears futile. It is most unfortunate the unscrupulous alternative vendors prey on novice builders who usually don't know what they don't know. Most of these builders end up burning tons of money that never has a payout and either lose interest or buy another, conventional engine and fly as a much wiser builder. We have a local Lyc-flyer who has a $40K pile of Eg******** in the corner of his shop to remind him of the years and dollars wasted in that pursuit.

But even after the above builder has documented his experience for all to see, gullible builders still line up for a shot of Kool-Aid and continue to pump money into the pockets of dubious vendors. I don't understand it. And y'all know who I'm talking about.

Having said that, I have much respect for experienced builders who understand what they face when fabricating an alternative firewall-forward. Their tenacity and creativity is to be admired and no doubt they are enjoying a special corner of aviation.
 
Last edited:
Alternate engines

Just finished David McCullough's book The Wright Brothers. Seems most folks thought they were wasting their time or maybe a little crazy. They ignored their critics and made it work.

In that spirit, I wish you great success. It is about time to move the engine technology forward. And we certainly don't want to lose the experimental aspect of experimental aviation.

Just my two cents, might be worth less.
 
First off, Jon, I really want to see the mount that lets you use a cheap automotive starter on a Lycoming. :)

Second... I don't think you should be surprised at the reluctance of VAF denizens and RV builders to be enthusiastic about alternative engines. I think the average RV builder is looking for a proven, reliably reproducible, no-tinkering-needed airframe (RV) with an equally stable, no-drama engine (Lycoming design). There are guys who want to really experiment, but the percentage of them building RVs is probably pretty small. If I were looking to develop an automotive engine for aircraft use, I don't know that I'd pick an RV to do it with... there are certainly easier airframes out there to play with different cowling, W&B, engine mounts, etc. And it's not like auto conversions don't work; it's just that the ones that are pretty well proven are too small for use in RVs. It's too bad there aren't any 160-180 HP Corvair or VW conversions.

Sure, there is some crossover - which is why we have a radial engined RV, and some Subies, a few Mazda rotaries and even the occasional V6 or V8. But by and large it's not going to be a crowd that enthusiastically embraces the bleeding edge of experimentation. Out of over 9,000 flying RVs - how many would you guess are flying with a non-Lycosaurus up front? Less than 5%? Less than 1%? And of course it will be a long time before anyone forgets the Eggenfeller thing, it's just human nature.

I have a lot of respect for the guys who are willing to go into uncharted territory with an engine. I'm not quite that "experimental".
 
Starter? Thread Drift?

First off, Jon, I really want to see the mount that lets you use a cheap automotive starter on a Lycoming. :)

Sure thing, with apologies for the thread drift! From March 1991 Sport Aviation: http://www.insanitize.com/vaf/starters_lightweight_high_torque.pdf

My mount was not the mount detailed in that article, mine is from Air-tec, a company in Florida. Still in business, will sell you one for $75 or so. Starter is a 1978 Toyota Cressida starter with the 9 tooth 'nose' gear replaced w/an 11 tooth gear. This setup does require a small cowl blister to clear the starter; my cowl was already set up for this.

This should probably be in the 'starter' subforum or something I suppose.

-jon
 
Last edited:
Probably one of the biggest reasons you don't see a lot of conversion engines on RV's is a simple fact of aeronautical engineering. Step one in a new aircraft design is to choose an engine - then everything is designed around that. Aerdynamics, structure, and perfomance all revolve around the choice of engine. Deviating from that choice almost always compromises the initial design critera in some way. RV's were created around the Lycoming - that is what the designer had in hand when he got started, and that is how the design evovled.

There are many aircraft designed around conversion engines - the Sonex is a great example among many. The airplane does great on the Aerovee engine, and as you try and deviate from that, you end up with compromises - a heavier nose, structure not designed for more load, etc. Pietenpols wre designed for old car engines. Heck, someone brought up Franklins - they fly GREAT in the airplanes for which they were desigend - certainly not "alternative" - except in the sense that if you are talking RV's, the airframes weren't designed with them in mind.

So look at the context when deciding why conversion engines get a bit of a cold shoulder in the RV world - the RV's weren't designed for them. Apart from what you think about conversion engines in general, and the buisness practices that surround some of them, they simply require more work to integrate, and there are many compromises that end up being made so that what you might gain in what area, you lose in another. Sometimes, those compromises ae EXACTLY what a person wants - for instance, you want a diesel because all you have in your part of the world is jet fuel. You'll accept the slower speeds and heavier empty weight because it is better than not flying at all. And if you just love to tinker and create, and that is your primary reason for owning an airplane - then Wow - you have found the right answer!

But back to the simple answer - RV's were designed around the Lycoming, and that is what they are happy with. Go to the Sonex board, go to the Panther community, go to many different groups that build airpalnes that were designed around different engines, and you'll find discussions centering on them. There are many great choices and combinations that work really well together - because they were designed for one another.
 
Last edited:
Good points Paul. We see the P85 (derivative of the Radial Rocket) designed around an LS V8 working very well. Jeff Ackland just sent me some flight testing updates this morning. Speed, fuel burn, looks and sound are very good. This is an attempt to find a less expensive, better performing, all USA made FF alternative to the now expensive and thirsty M14 radials. So far so good. Jeff has plenty of experience in the field, having done all the development and test flying on the V8 Legend years ago.

I've been happy to help with the ECU and some cooling system ideas but Jeff has done all the real work. Some of you may have seen the aircraft at Oshkosh this year. Great concept, carrying the Rocket type concept one notch up in performance.
 
Hi Sam,

I don't see your Legal Eagle listed in your sig line. Which Lyc powers it? Or is it one of the Continentals? ;-)

This discussion keeps wandering off into the weeds. I've never said that Lycs are just as unreliable as conversion engines. I *do* say that they are far from perfection, as some of the True Believers who post here seem to think. I have no problem with people making legitimate points about the risks and difficulties in trying a conversion. Those points *should* be made to anyone that has no background in the subject and hasn't done their research. I spent years weighing all those issues, and even bought a Lyc O-360 to hang on my -7. I found that I just couldn't do it. I wanted to at least try something different. I fully understand that the plane will be worthless, and there's significant risk it won't be as fast, or efficient, or 'safe',or etc etc. But then again, it *might* be better, in some, or even a lot of ways. But it will be *my* project.

Alt engine failures are like the violent crime rate. The violent crime rate in the USA is the lowest it's been in many decades, but we seem to see *every single incident* on the national news, so most people believe we live in the most violent period in the history of the world. We seem to hear about every single alt engine failure (recycled, over and over, for decades), but the guys that are successful just ignore hostile forums like this and continue flying.

Yes, unscrupulous vendors like the previously mentioned Eg****** cause widespread grief to hundreds of unsuspecting builders. But this more of an indictment of our messed up legal system that is incapable of stopping criminal behavior, than indicative of any actual engine problem. There are lots of unscrupulous vinyl siding dealers, but vinyl siding is still a viable exterior wall covering for some people. There are bad brick layers, too.

So if a newbe comes along & wants to mount the latest 2 stroke outboard motor on his RV-10, don't come up with some time wasting emotive statement like, 'Not with *my* family!'. Be productive. Ask if they have the skillset to engineer and weld up a motor mount for it. Do they have the skillset to redesign the fuel system. Have they calculated the effects on weight & balance, and fuel capacity. Can they do a proper cooling analysis. Do they have time to do all the extra debugging that will be required. Etc, etc. Then encourage them to post their calcs, methods, etc for 'peer review', and try to help them sort through errors and omissions. They may (probably) calculate themselves out of the idea, and move on to a Lyc. Or...we might all discover the next great a/c engine. :) But I'll bet that most of us will actually learn something new during the process.

Charlie
 
Last edited:
Keep up the good work Charlie!

My mission currently cannot accept additional research and development.

I am running a VW.....
 
Hi Sam,

I don't see your Legal Eagle listed in your sig line. Which Lyc powers it? Or is it one of the Continentals? ;-)

Charlie, the Legal Eagle with its 1/2 VW has been sold to a very experienced pilot (much experience flying the world's heaviest glider....) who is enjoying it immensely just as I did. That little bird was designed around the 1/2 VW so builders are using the intended engine in that case.

In addition to the VW I also have ~250 hrs of two-smoke Rotax time, so I know of what I speak when it comes to non-Lycs. And my latest project was designed for something other than the O-200 going in it so I guess I have one foot in each community. :)
 
Last edited:
First off, Jon, I really want to see the mount that lets you use a cheap automotive starter on a Lycoming. :)

Second... I don't think you should be surprised at the reluctance of VAF denizens and RV builders to be enthusiastic about alternative engines. I think the average RV builder is looking for a proven, reliably reproducible, no-tinkering-needed airframe (RV) with an equally stable, no-drama engine (Lycoming design). There are guys who want to really experiment, but the percentage of them building RVs is probably pretty small. If I were looking to develop an automotive engine for aircraft use, I don't know that I'd pick an RV to do it with... there are certainly easier airframes out there to play with different cowling, W&B, engine mounts, etc. And it's not like auto conversions don't work; it's just that the ones that are pretty well proven are too small for use in RVs. It's too bad there aren't any 160-180 HP Corvair or VW conversions.

Sure, there is some crossover - which is why we have a radial engined RV, and some Subies, a few Mazda rotaries and even the occasional V6 or V8. But by and large it's not going to be a crowd that enthusiastically embraces the bleeding edge of experimentation. Out of over 9,000 flying RVs - how many would you guess are flying with a non-Lycosaurus up front? Less than 5%? Less than 1%? And of course it will be a long time before anyone forgets the Eggenfeller thing, it's just human nature.

I have a lot of respect for the guys who are willing to go into uncharted territory with an engine. I'm not quite that "experimental".

Here ya go:
http://www.aeroelectric.com/Reference_Docs/Starters/Lycoming_Starter_Adapter.pdf

Mark Landoll sold a welded 4130 adapter for years that was pretty simple to make. I've got the drawing for it around here somewhere, too.

Real Aircraft Starters are made by the Aviation Elves, in a hollow tree after hours, between runs of cookies. Unlike automotive starters; they're made by the automotive elves.

Edit: After Mike S' post, I'm realizing more and more what I already knew; humor is a hard thing (at least for me) to convey in a forum post. I'm sorry. The point of the above is that most a/c piston engine starters are sourced from automotive (or tractor, or etc) vendors. A lot of certified parts are. For an off the wall example, one of the marine out-drive hydraulic pumps for the tilt mechanism is a drop-in (higher power, more reliable) replacement for a Temco/Globe Swift gear/flaps pump. Which leads me to believe that both are likely sourced from the same place. Now, I have no proof of that. But if you follow the antique/classic restorers, you've seen many references to parts that were sourced from automotive vendors.

The % of RVs with alt engines is pretty low, for good reason. Most either don't want the development time, or understand their limitations (a man's got to know those...). But it's likely higher than 1%. I'm personally acquainted with at least 8 successful rotary powered RVs (one with around 1500 hrs, all rotary powered) that I can remember offhand; there are a lot more who I don't know personally. And rotaries are probably the smallest segment of alt engine'd RVs.

Charlie
 
Last edited:
Speaking of hostile.......................................

Please look again, Mike. I edited the post immediately because I didn't want it misinterpreted. Should have included the smiley before I hit 'send'.

Apologies to Sam & the list if that seemed hostile.

Charlie
 
That's easy to explain;
Rutan was into aerodynamic advancement. It's best to make changes incrementally, so traditional power would be the way to go.
People that develop power plants want well proven airframes.

One of Rutan's failures, (his words, not mine) was the Pond Racer. it failed because they were never able to get the V6 nissan racing engines to work reliably. Getting an auto conversion to run well, be economical and deliver the power of a lyc is not easy. I would never try to discourage a technically adept experimenter from pursuing it, but I definitely would try to discourage a person new to the hobby who is not even a pilot and has never so much as changed the oil in his lawnmower from going in that direction (and I know guys like that) because they will get burned (figuratively or literally). In many cases they are driven in that direction by colorful advertising in Kitplanes and nothing else.

Just to build a stock RV with an O-320 is way more work than people realize who have never done it. To add to that an engine that the vendor himself might never have flown behind makes success that much more improbable. So people who do try to breath some reality into those dreams are not necessarily being negative. They are trying to prevent heartbreak, bankruptcy or worse. It's not necessarily malicious or disrespectful in many cases.

On the other hand there are talented, technically savy people who have accomplished great things. For you guys blasting around in a mazda in an RV my hat is off to you. You got it all to work - you have even more tenacity than us guys who just built the airplane.

One thing about rotax, they have succeeded in delivering better power to weight than the tranditional engines. That's why they are in all the LSAs. The 912 is very light for its output. But it is complex and expensive. It's hard to have it all.

[ed. I hope this doesn't cause any thread drift, Scott, but when you mentioned the Rutan Pond Racer I had to stop and reflect on just how beautiful that airplane was. In my humble opinion it was every bit as beautiful as the Bugatti 100 racer. Rest in Peace, Mr. Rick Brickert. dr]
 
Last edited by a moderator:
One of Rutan's failures, (his words, not mine) was the Pond Racer. it failed because they were never able to get the V6 nissan racing engines to work reliably. Getting an auto conversion to run well, be economical and deliver the power of a lyc is not easy. I would never try to discourage a technically adept experimenter from pursuing it, but I definitely would try to discourage a person new to the hobby who is not even a pilot and has never so much as changed the oil in his lawnmower from going in that direction (and I know guys like that) because they will get burned (figuratively or literally). In many cases they are driven in that direction by colorful advertising in Kitplanes and nothing else.

On the other hand there are talented, technically savy people who have accomplished great things. For you guys blasting around in a mazda in an RV my hat is off to you. You got it all to work - you have even more tenacity than us guys who just built the airplane.

One thing about rotax, they have succeeded in delivering better power to weight than the tranditional engines. That's why they are in all the LSAs. The 912 is very light for its output. But it is complex and expensive. It's hard to have it all.

[ed. I hope this doesn't cause any thread drift, Scott, but when you mentioned the Rutan Pond Racer I had to stop and reflect on just how beautiful that airplane was. In my humble opinion it was every bit as beautiful as the Bugatti 100 racer. Rest in Peace, Mr. Rick Brickert. dr]

The Pond Racer's engines were initially bedeviled by EMI gremlins in the ECUs early on, the same as what Formula 1 engineers were facing in the mid '80s. Later on, when those problems were licked, I believe the oil cooling was too good and they had problems getting it up to temperature. The latter should have been easy to solve with a $50 oil thermostat like we use today.

The basic Electramotive developed VG30 engines were very reliably outputting over 800hp in the Nissan GTP cars at this time. It seems many things were lost in translation from the car to the tight aircraft cowlings however and the Pond's engines suffered many problems. They'd switched from gasoline to methanol I believe too plus had the PSRUs as well, so the package was quite different from the car.

I've never managed to talk with anyone directly involved with the engine development in the aircraft, would be a fascinating story I'm sure.

It was really leading edge technology at the time and Reno has seen nothing like it since really. I saw it fly at Reno and it sounded truly wonderful with both props in synch. It was a real shame and shock to lose both Rick and the Pond Racer there.

These days, what it takes is understood to a much higher degree and we have thousands of auto powered aircraft working very well worldwide- VW, Subaru, Chevy, Ford, Suzuki, Honda, Corvair, Mazda etc. The RV world just does not generally know much about that world. When they are done right, they are certainly cheaper to buy and operate than Lycomings- the track record is there now to prove that from a number of sources. When done wrong, they are a nightmare on a quick ticket to removal in many cases.

It hasn't been an easy journey for many, for others, they got almost everything right the first shot. My hat's off to all those who stuck with it and are now enjoying the fruits of their labor.
 
There is a guy in our RAA chapter who built a zenith 601 with a subi. He budgeted 6 months and $7k. It took 2 yrs and $14k because of all the dead ends he went down. He put a bunch of hrs on it, like 400+ and it had some interesting advantages, like lots of available cabin heat in winter. But it did not end up being cheaper than an o200 and it required a lot of maintenance. It was great to hear his objective presentation of real world results, some pro, some con, from a guy who had done it rather than just the back and forth of opinions of those who have not, like myself. Opinions are like....well...you know the rest of that saying.

Ross, what are the conversions in the 150-180 hp class that are proven and turn key and cheaper than a lycoming? I don't know of any but I have not really looked in to it. I would be curious.

I scratchbuilt an rc model of the pond racer. Back in the 90s. It looked amazing in the air and flew like it was on rails. Very sad that the real one was lost.
 
Last edited:
There is a guy in our RAA chapter who built a zenith 601 with a subi. He budgeted 6 months and $7k. It took 2 yrs and $14k because of all the dead ends he went down. He put a bunch of hrs on it, like 400+ and it had some interesting advantages, like lots of available cabin heat in winter. But it did not end up being cheaper than an o200 and it required a lot of maintenance. It was great to hear his presentation to real world results from a guy who had done it rather than just the back and forth of opinions of those who have not, like myself.

What are the conversions that are proven and turn key and cheaper than a lyc?


I scratchbuilt an rc model of the pond racer. It looked amazing in the air and flew like it was on rails. Very sad that it was lost.

There are no current, proven reliable turn key vendor offerings of alternatives in the 150-200hp class besides Belted Air Power http://www.beltedair.com/ with the Chevy 4.3 but not sure if you can get the entire package. The site does not appear to have been updated for around 5 years. Maybe Jess will pipe in here. Most alternative engine packages are in the sub 130hp class like the VW (Aerovee/ Sonex, Great Planes, Revmaster etc.), Corvair (Azalea Aviation, WW), Suzuki (Raven Redrives, AirTrikes), Subaru (RAM Engines) and Honda (Raven Redrives, Viking).

In the higher hp area, Titan Aircraft were doing V6 Suzuki and V6 Honda engines for their own kits but seem to be concentrating on an LS based V8 now. Robinson offers LS based engines as does AutoPSRU (used to be Geared Drives) and Supermarine Aircraft.

The key to a 540 replacement is probably some lightweight LS based engine with a proven, low cost redrive like Jeff is using in the P85. Should be weight competitive with the IO-540s and offer at least 50 to 100 more hp at the same time. Looks possible to do a FF installation for about $15K if you DIY. There are a handful of RV10s flying with these engines.
 
Last edited:
I think two problems I have noticed is some builders think they are better than factory that built eng.I am using stock (except clearances) Subaru 2.5 with SDS ignition/fuel injection control (as they have RV6) and have suplying racing/aircraft for 20 + years.Trying to modify auto computor for aircraft is folly at best.Other problem is mickey mouse cooling setups that cause failure of auto engine.This is my humble opinion...Tom
 
I for one am glad there are people willing to experiment and push the boundaries. It's 'Experimental Amateur Built', not 'Bone stock plug-and-play Amateur Built'.
I still find it funny to hear RV builders/owners refer to the design as "Experimental". The RV's are now about the *least* experimental amateur-built aircraft you could build. Prepunched kits, preformed fibreglass, preformed canopy... I grew up at an airport where amateur-built aircraft came in as a stack of uncut wood or sheets of aluminum. One builder hand-carved his spar out of a Douglas Fir tree.
 
I built a Turbo Mazda Rotary for my RV-8. I don't feel the VANSAIRFORCE forum was hostile. I received a lot of support and a few kind personal messages.
I also met an RV owner or 2 who commented on reading about some SHIPCHIEF guy who was installing a rotary. They never expressed anything but respect.
I flew that engine 16 hours. Ross Farnham was very helpful regarding turbocharger sizing, and that's one example off the top of my head.
The greatest negativity came from my son, who watched the whole thing come together, and saw me remove the cowl after nearly every flight.
He was worried about my safety.
I removed the engine because I wasn't advancing the air frame thru the Phase 1 testing, I was just flying test runs on the engine and staying close to airports. Finally, I overheated my turbocharger housing, and the whole list of small teething problems added up. It took me 7 calendar months to remove the 'power egg' and install a Lycoming. I built the RV-8 and Mazda with the clear intention to be able to do this.
The Mazda? A fantastic power plant. I'll put it to another task.
 
Lot's of things going through my mind on this one. I think one of the major issues with alternative power is that very few builders have real knowledge of what kind of development work is necessary to make an IC engine work in a given application reliably and with the desired performance. I do and I know I don't have the time or resources to do it, so I am not going that way.

That said, the thought of alternative power seems to be irresistible. I think this is for one of two (or both) reasons:

1) The desire for a lower cost powerplant
2) The desire for features

Lower cost is easy to understand and relate to. Features less so. As far as features go people can be looking for more power, lighter weight, or fancier (electronic) controls for fuel or ignition. They may be others, but I think these are the big ones. What they assume is that they will be able to achieve these goals while maintaining the reliability performance the same as a traditional AC engine based on the reliability performance of the machine the engine was designed for. It is a flawed assumption, but the promises usually overwhelm the desire to critically challenge them.

In the end, yes, you can make an auto (or other) conversion work and we all know that. What is not known is how much resource will be burned.

All THAT said it bothers me every time I look at the cost of a Lycoming. It is essentially a big Volkswagen with thrust capability built into the crank/bearing design. It should be able to be profitably sold for around $5K retail, but is 5 times that due to sales volume and legal issues. And so it goes...

Tim
 
That said, the thought of alternative power seems to be irresistible. I think this is for one of two (or both) reasons:

1) The desire for a lower cost powerplant
2) The desire for features

I would add:

3) Desire to be different. That is one reason I've been piddling with my RV-9A w/13B for 10+ yrs. now. Once it's flying it will be a lot of fun to take it to airshows, and just be different when parked among the many RVs with Lycomings... :)

4) You're just a guy / gal who really finds enjoyment in "wrenching" / working on your own a/c. If you're the type of person that has to reach for your checkbook to pay an A&P every time you have an engine issue; then (IMO) you're definitely better off sticking with a Lycoming...

Doug
 
Last edited:
Back
Top