A Little Eggenfellner History

[Ted Johns]

Originally Posted by janeggenfellner

Nothing here is done by faith. We put our
lives on the line every time we test a new engine package. But we do it
because we believe in real world testing. Once the thing has logged 200
hr on the stand, get out of the chair and fly the thing. When someone
ask me how many flight hours we have on the 2008 model 3.6, I know that
they have no idea what this is all about. It is about, as safely as
possible, use the latest in automotive engine technology, in an airplane.

Jan

I waffled about posting the following comment. Then Jan posted a few more (perhaps unintentionally) disingenuous comments.

Jan, I think Dan was implying that your customers are flying on faith.
You may not do anything on faith, you may have the most wonderful design
and testing in the world. But without published test protocols or design
specifications, your customers must have faith. In the certified world
there are a lot of assurances, the FAA PMA, the ability of any A&P to
send in a service trouble report, the authority of the FAA to issue an
AD to force a fix. In the case of Lycoming, the longevity and relative size of the company is an assurance.

In the experimental world, all we have is the transparency of the
manufacturer. Speaking for myself, the requirement for transparency goes
up in direct proportion to the cost and life safety aspects of the part
in question.

Additionally, most experimental parts are sold as individual components.
The transparency is a given in as much as the buyer is going to assemble
the components. Uniquely, your experimental product is a complicated
assembly, with workings that are not inherently transparent.

It is simply disingenuous to suggest that all your customers need is a demo flight, that there is no need for hard data.

[Ted Johns]

Originally Posted by rv6ejguy

If you are happy flying your traditional engines, by all means continue- perhaps you are the type of person who still drives a 1980 Impala and thinks it is just great. But if you've never driven a 2008 Lexus, you don't have much to compare it to. Yes, the old Impala gets you to the airport, it just isn't very refined by todays standards.

snip...

Why should we subject ourselves to this level of mediocre refinement in our aircraft when most of us would not in our cars? That is the question asked by many and the reason why Jan is in business.

I would love to have that "Lexus" refinement in my aircraft engine. How much safety do I have to trade for it? How much reliability? Can anyone tell me?

[L.Adamson]

Originally Posted by rv6ejguy

Why should we subject ourselves to this level of mediocre refinement in our aircraft when most of us would not in our cars?

To be honest, I don't like the idea of having to use a prop reduction to get high revving auto engines down to efficient prop rpms. I don't like the idea of cramming radiators and hoses in every possible spot, when an air-cooled airplane engine is quite sufficient and much simpler.

I like the idea of hydraulic constant speed props,
versus the slower electric types, including associated wiring & brushes.

As one can see, a "modern" auto engine really needs a lot of makeshift additions, to do what an airplane engine has been doing all along....

L.Adamson -- Chevy diesel Silverado -- no Impala

[tloof]

I watch these posts from time to time but haven't ever responded to them yet, but I do have a few comments to make. While it is great that Jan & others are attempting to offer alternatives to the pricey Lycomings, the fact is the Lycoming is still the ultimate piston engine design for GA aircraft use for a number of reasons:

1) Lightest weight for the power produced
2) Lack of a head gasket which avoids blown head gaskets when running at high power settings (the very nemesis of early designs & why all air cooled aircraft engines from World War 2 on were designed this way)
3) Air cooled design that minimizes the complexity of a water cooled issues as well as reducing overall weight
4) Price at the current time with the clones is still cheaper than alternative engines bought as a complete package (yes, perhaps someone converting a junkyard engine can do it for less, but it's doubtful that it is as reliable as a Lycoming in my opinion).
5) Much larger in cubic inch capacity and thus much less stressed than the alternative engines (and just think, they are still lighter than alternative engines that are half the cubic inches in size...how are the newer alternatives considered to be better when they can't even match the lighter weight of the Lycoming?).

While the Lycomings weren't designed originally with electronic ignitions and other more modern advancements, most all of that is now available for any Lycoming used in an experimental amateur built aircraft, so they match the Subaru & Rotary engines in that regard and still are more simplistic and more reliable. Also, alot of the previous problem areas have been designed out in the clones such that they are WAY more reliable now than even the older Lycoming engines (one of these major design changes is a redesigned oiling system that feeds more oil down the pushrods to the valves which has now all but eliminated the old valve sticking problems of the original Lycoming designs...even Lycoming has done the same by upping the oil pressure to 100 psig now to get more oil flow to the valves on all their latest new engines).

All in all, until there is HUGE advancement in some new engine design, the current alternative engines are no advancement at all and in fact can't out perform a Lycoming engine installation. That reason alone makes me wonder why anyone would pay so much money to install one...yeah if it were truely half the cost with only a 5% or less loss in performance, then yes it would be worth it! (but that is obviously not the case at this time). The reality is that the Lycoming is an extremely well designed engine for the specific mission it was designed for!! Any auto conversion is NEVER going to be able to out perform it. But, let's assume that someone does manage to match the performance at less cost, well that will only help us all because Lycoming and the clone manufacturers will then just drop their prices to maintain their market!

[gmcjetpilot]

Originally Posted by janeggenfellner

But you see, it is the other way around. It means everything. The 2008 3.6 is superior to any air cooled direct drive engine. If you question this then I can not help Jan Jan

Superior in what (that benefits aircraft use)? I have always said, when any alternative engine in the 180-200hp range, which fits my RV7, goes faster, on the same or less fuel, with a hydraulic prop and lower installed weight, than my Lyc, I'm writing a big check. We can agree to disagree my friend. Cheers, keep up the good work!

[rv6ejguy]

Originally Posted by tloof

I watch these posts from time to time but haven't ever responded to them yet, but I do have a few comments to make. While it is great that Jan & others are attempting to offer alternatives to the pricey Lycomings, the fact is the Lycoming is still the ultimate piston engine design for GA aircraft use for a number of reasons:

1) Lightest weight for the power produced
2) Lack of a head gasket which avoids blown head gaskets when running at high power settings (the very nemesis of early designs & why all air cooled aircraft engines from World War 2 on were designed this way)
3) Air cooled design that minimizes the complexity of a water cooled issues as well as reducing overall weight
4) Price at the current time with the clones is still cheaper than alternative engines bought as a complete package (yes, perhaps someone converting a junkyard engine can do it for less, but it's doubtful that it is as reliable as a Lycoming in my opinion).
5) Much larger in cubic inch capacity and thus much less stressed than the alternative engines (and just think, they are still lighter than alternative engines that are half the cubic inches in size...how are the newer alternatives considered to be better when they can't even match the lighter weight of the Lycoming?).

While the Lycomings weren't designed originally with electronic ignitions and other more modern advancements, most all of that is now available for any Lycoming used in an experimental amateur built aircraft, so they match the Subaru & Rotary engines in that regard and still are more simplistic and more reliable. Also, alot of the previous problem areas have been designed out in the clones such that they are WAY more reliable now than even the older Lycoming engines (one of these major design changes is a redesigned oiling system that feeds more oil down the pushrods to the valves which has now all but eliminated the old valve sticking problems of the original Lycoming designs...even Lycoming has done the same by upping the oil pressure to 100 psig now to get more oil flow to the valves on all their latest new engines).

All in all, until there is HUGE advancement in some new engine design, the current alternative engines are no advancement at all and in fact can't out perform a Lycoming engine installation. That reason alone makes me wonder why anyone would pay so much money to install one...yeah if it were truely half the cost with only a 5% or less loss in performance, then yes it would be worth it! (but that is obviously not the case at this time). The reality is that the Lycoming is an extremely well designed engine for the specific mission it was designed for!! Any auto conversion is NEVER going to be able to out perform it. But, let's assume that someone does manage to match the performance at less cost, well that will only help us all because Lycoming and the clone manufacturers will then just drop their prices to maintain their market!

Perform is such a broad term and never is so final. In fact, several auto conversions that I'm aware of are faster than the typical Lyconental powered aircraft. I've listed some of these previously. Perhaps you should review your data.

Head gasket failures are not an issue on the popular modern automotive engines like the Phase 2 EJ25s, EJ22, EZ30, EG33, LS-1 through LS7.

Air cooled engines operate at much higher thermal stress levels- hence their issues with cracking heads to this day. Mechanical stresses are similar on both types as has been shown before.

I do agree that the clones are overall better engines today than Lycoming's original design.

I've said before, that no commercially available packages currently match the weight, fuel burn and speed in the 200 hp class compared to Lycomings. This is not the reason people buy alternatives or there would be no market.

Other comments about PSRUs being "makeshift" don't make sense. Again, as previously mentioned, there have been way more gearbox equipped aero engines built and flown than direct drive aero engines. Today, you have your choice of several PSRUs which have hydraulic prop capability should you desire these. Again, there have been hundreds of thousands of electric props built and they work just fine unless you are doing aerobatics.

[Adam]

I wonder if the engineers at Subaru designed there engine to work at full HP for much longer then a few minutes? Most car engines don't see much more 30% power at any time. Porsche tried to make a aircraft engine and they didn't succeed, I'm sure they have the money for R&D. Unforturely, the amount money that it would take to develop a new aircraft engine for the small amount of engines needed don't make it feasible. By the way, I would love a Lexus engine, if it were designed for aircraft!

Just my opinion, nothing more!

[Kevin Horton]

Originally Posted by Adam

I wonder if the engineers at Subaru designed there engine to work at full HP for much longer then a few minutes?

Back in 1989, Subaru set a long duration, high speed endurance record with the original Subaru Legacy. Is an average speed of 138 mph (including stops to refuel, change tires, change drivers etc) for 18.5 days good enough for you? Certainly the engine has changed a lot since 1989, but this gives some idea of the robustness of the engine that Subaru designs.

I have little concern about the core Subaru engine. The big questions are on the PSRU, and other systems that must support the engine to allow it to keep running.

[Jconard]

Well now I see that the claim is again that every engine package is run for 200 hours on a test stand before flight.

But when I asked about the RV-10 package (the old one not the 3.6) the answer was that very little teststand time had been done, but much test flying was done in Dan's (RIP) plane. Unfortunately that comment implied that the in flight testing was a cumulation of trouble free hours. Even that claim was false as everyone familiar with that tragic chain of events knows. How many hours before and after the first turbocharger melted and siezed? Any disclosure on that? What has been done to fix that problem, and how has the fix been tested?

I recieved no answer to the question of how much testing had been performed, on the stand, with each permutation of the package, including the prop. Most of the test stand testing was apparently done with a four blade prop, though I think the flying was done with two blades removed...that is certainly how the airplane arrived at OshKosh.

Maybe I am paranoid from cross examining uncooperative witnesses all day long, but I too found that most of the answers were vague or avoided (artfully) the actual question which was asked.

Smoothness? Great feature. No doubt about it a smooth engine and hot water heat are nice.

Reliable hours? No data. There was a claim that there have only been 2 gearbox failures, but the fleet is grounded, and when other examples of failures where bearings shelled out, or gears stripped, were raised we all learned that such "events" are not calculated in the failure matrix.

Speed? Ross is right that the fastest conversion examples are faster at the top end than average examples of traditional powered planes...but at what fuel burn and weight? If speed is the measure, fuel burn be damned, then we need to factor in the super 8's and others.

Ross is correct that the fuel/speed numbers are a nod to the lycoming. Ross is correct that weight is an often substantial nod to the traditional.

System simplicity also goes that way. It is not just that props are electric it is that the pilot workload to manage the controllers is high, and apparently not intuitive. A beautiful RV was just lost because the experienced pilot builder chose the wrong buttonology for the prop controller, and had insufficient power to go around. We know that Dan struggled to work out the bugs and get systems control over his "ready for prime time" prop controller. Many times making it difficult or impossible for him to get the plane safely on the ground, or to execute a low risk go around.

It is great to get rid of the red knob, but how many knobs, switches and other controls are added in the mix?

It is great to have computer controlled waste gates....but they appear to be operated by a cable hooked to a Ray Allen trim servo???? Is that safe? maybe it is, maybe the rim servos have the ability to react quickly enough to prevent an overboost or underboost scenario. All I know is that no other aircraft installation uses a cockpit mounted trim servo to manage the waste gate or blow off valve. I am not aware of any auto application which does either. Most are mechanical and pressure operated and located immediately with the valve they actuate because speed and responsiveness are critical. Again is this approach safe and reliable? maybe it is, but we have no way of knowing, we have no data to support it, and there are few if any successful flight hours to support it.

I do not object to designing by heart. Historically some of the most successful race teams did this...Collin Chapman is reputed to have removed tubes in the Lotus Seven chasis one at a time until it collapsed on it self, and then added the last tube back before affixing a rigid and structural skin. The car eventually proved reliable and was super light/fast. Many drivers died along the way. When the chasis fails mid corner, there is little one can do to recover.

In an RV, a dead stick is a far more dangerous event than in a Citabria or Cessna. The planes have short wings, and high wing loading, power off they come down like a rock. Yes a profficient pilot should be able to get it on the ground if there is a suitable place to do so, and at least some altitutde. As I get older, it seems prudent to take every step to avoid that situation all together.

It is a strange position that I find myself in because if I think "do I want a smoother, more modern engine that starts like a car, with better heat, and lower pilot workload?" the answer is unquestionably yes. But if I also ask "do I want a controlled package with KNOWN characteristics and predictable behavior" the answer is also yes. Maybe that is the problem. Maybe if a single or perhaps two or three core engines were used for many packages that were all identical, and real transparent data was available so that failures could be predicted and avoided....it would be a more comfortable proposition.

To put it in the perspective of the software world I used to inhabbit....it is fine for a small company supporting a handful of users to constantly install bleeding edge, relatively untested software because ad-hoc support issues are small. But if you run a mission critical enterprise wide application you would be a fool not to control and enforce consistency and a controlled evolutionary approach to development/change.

These are just my opinions and observations. Many will not agree. Ultimately it is a risk management decision we all must make.

[DanH]

<<Why should we subject ourselves to this level of mediocre refinement in our aircraft when most of us would not in our cars?>>

If we limit the comparison to just the engines, you're absolutely right.

Question is, when are you going to start demanding the same level of engineering for the rest of the powertrain?

Ross, you're probably the internet's #1 defender of alt-engines. Yet you're personally flying a engine package (Subaru + Marcotte) that shakes the snot out of the whole airframe when it passes through the first resonant period at 1350 RPM. The only reason it lives (so far) is because the gearbox parts are massive. What you have is an unrefined system; it doesn't work very well and weighs far more than an engineered system would require.

Now consider the Egg system. Much better by all reports; Jan's approach is fundamentally correct. However, lacking the slightest clue as to actual vibratory shaft loads, his only alternative was to create a third gearbox iteration after the first two didn't turn out to be reliable. The new box is a nice piece, but still classic TLAR design. There's no evidence that shaft loads were predicted at the design stage or measured in test. It is just "beefier", and as a result it weighs 15 more lbs.

Start demanding better and you might get it; free markets work that way. And please, on a personal note, don't shoot the messenger. I didn't spend all the time to learn "useless technical stuff" just I could could knock alt-engines. I'm one of you.....and I see how good it could be.