Are :Certified" aircraft engines tested for thousands of hours?

Not at all:

FAR 33.49 Endurance test.

(a) General. Each engine must be subjected to an endurance test that includes a total of 150 hours of operation (except as provided in paragraph (e)(1)(iii) of this section) and, depending upon the type and contemplated use of the engine, consists of one of the series of runs specified in paragraphs (b) through (e) of this section, as applicable. The runs must be made in the order found appropriate by the Administrator for the particular engine being tested. During the endurance test the engine power and the crankshaft rotational speed must be kept within ±3 percent of the rated values. During the runs at rated takeoff power and for at least 35 hours at rated maximum continuous power, one cylinder must be operated at not less than the limiting temperature, the other cylinders must be operated at a temperature not lower than 50 degrees F. below the limiting temperature, and the oil inlet temperature must be maintained within ±10 degrees F. of the limiting temperature. An engine that is equipped with a propeller shaft must be fitted for the endurance test with a propeller that thrust-loads the engine to the maximum thrust which the engine is designed to resist at each applicable operating condition specified in this section. Each accessory drive and mounting attachment must be loaded. During operation at rated takeoff power and rated maximum continuous power, the load imposed by each accessory used only for an aircraft service must be the limit load specified by the applicant for the engine drive or attachment point.

(b) Unsupercharged engines and engines incorporating a gear-driven single-speed supercharger. For engines not incorporating a supercharger and for engines incorporating a gear-driven single-speed supercharger the applicant must conduct the following runs:

(1) A 30-hour run consisting of alternate periods of 5 minutes at rated takeoff power with takeoff speed, and 5 minutes at maximum best economy cruising power or maximum recommended cruising power.

(2) A 20-hour run consisting of alternate periods of 11/2hours at rated maximum continuous power with maximum continuous speed, and1/2hour at 75 percent rated maximum continuous power and 91 percent maximum continuous speed.

(3) A 20-hour run consisting of alternate periods of 11/2hours at rated maximum continuous power with maximum continuous speed, and1/2hour at 70 percent rated maximum continuous power and 89 percent maximum continuous speed.

(4) A 20-hour run consisting of alternate periods of 11/2hours at rated maximum continuous power with maximum continuous speed, and1/2hour at 65 percent rated maximum continuous power and 87 percent maximum continuous speed.

(5) A 20-hour run consisting of alternate periods of 11/2hours at rated maximum continuous power with maximum continuous speed, and1/2hour at 60 percent rated maximum continuous power and 84.5 percent maximum continuous speed.

(6) A 20-hour run consisting of alternate periods of 11/2hours at rated maximum continuous power with maximum continuous speed, and1/2hour at 50 percent rated maximum continuous power and 79.5 percent maximum continuous speed.

(7) A 20-hour run consisting of alternate periods of 21/2hours at rated maximum continuous power with maximum continuous speed, and 21/2hours at maximum best economy cruising power or at maximum recommended cruising power.

WHY AUTO CONVERION ENGINES?

1) Liquid cooling

Hundreds of Eggenfellner powerplants are flying all over the world today from Alaska to South Africa in every type of climate.   Our advanced cooling system eliminates all concerns for in hot weather and hard starting in any weather.  Liquid cooling eliminates concern for shock-cooling, the need for pre-heating, and provides excellent cabin heating for winter operation without the concern of carbon-monoxide fumes entering  the cabin.  

2) Insurance

The major insurance providers recognize our outstanding safety record and reputation and you should expect a normal premium. 

QUESTION: Can I get insurance coverage for my airplane if I use a converted Subaru engine?

ANSWER: If you use an approved engine package then you can, please see below:

Dear Mr. Eggenfellner:

"Avemco offers insurance for aircraft equipped with the Eggenfellner engine provide the insured meets its usual underwriting requirements,"

Sincerely, Richard Harder

Sr. Insurance Counselor, Avemco Insurance Company 1-800-638-8440 ext.4382

Jan, I called Avemco this morning about liability insurance for an RV7a with your engine. For me it would cost 674/year for the minimum coverage (100,000/person, 1,000,000/occurrence) it takes for me to keep my hangar. They don't care if it's got a Lycoming or your engine. Either one costs 674/year for minimum liability.  I don't know if this pricing would be for everyone.  I've been an Avemco customer for several years and have not filed any claims (knock on wood) yet. I'm not really a high time pilot or anything.

I'm a low budget homebuilder that works in the energy sector. I work a regular job, then build the RV some nights and most weekends. The thought of me carrying hull insurance makes my check book whimper. So, I buy liability and fly safe.  I'm buying your engine package because it looks like a great product, it's priced well, and I want relatively fast and clean installation.  My close friend has spent several months and about 25,000 bux on his RV6 engine install (reman Lycoming 0-360) which is cool, but he has more time and deeper pockets than I do.

Jim

I have my Eggenfellner converted Subaru powered GlaStar insured through Regal Aviation Insurance in Hillsboro, OR.  My agent is Barb and you can contact them at 800-275-7345 or 503-640-3071. My premium for full coverage on 75K hull value is $1690.00 a year.

Charlie Walker
 

Scott at SKY SMITH  will insure airplanes with the converted Subaru for low rates.  800-743-1439

I requested a quote from SkySmith.  They responded to me within 30 minutes with a price of $276 for a policy that started at $25K,
I would recommend them to anyone (800-743-1439).  Glenn in Arizona -9A fuselage.

I just called EAA & got connected to a Falcon guy (Ladd Gardner).  He said "no problemo"  on either Builder's Insurance or Flight Insurance.  He said Builders' insurance is 1% of declared value.  He said they'd even cover the first flight, although they may require that someone with more PIC hours do the first couple hours, to be covered.   He also said no insurance problem at all or any penalty if Eggenfellner FWF package.

Brian

 I found that an instrument rating helps by about $400 a year for a pilot with low hours (-200). Maybe more with your hours.  Falcon quoted me, that I will pay $1700 a year with my 150hrs and an instrument rating. This includes $85K hull and 1M in liability with my Subaru conversion and includes first flight as long as I get 10hrs in the model.

I am looking at my policy from Falcon Insurance Agency of Houston for my  RV-9A and it is with AIG - not Globe. I do NOT have 500 hours. I was at about 250 when I took the policy out.

Call Mark Brown at 800-880-8822

I am building a Velocity and considering the Eggenfellner.  I talked to one of the insurance tents at Oshkosh.  Can't remember what the company was, but it was the EAA affiliated one?  He quoted me the SAME price for insuring the Velocity with a Lycoming and with an Egg.  As far as insurance is concerned, he said the Egg was an approved installation and carried no insurance premium.

Marc

I have had insurance since day one through AIG.  I had 109 hours the first time and 300 when I renewed last week.  The only difference in the policy for a SUB compared to a Lyco was that during phase one testing (1st 40 hours) my deductible was 10% of the insured value.  After phase one it dropped back to $100. Hope this helps.

I have an RV9A with an older 2.5 normally aspirated Egg engine with the Quinti hub.  For the first year, I paid $1950 for $80000 hull coverage plus liability.  When I renewed this year I paid $1740 for the same coverage with 310 total hours and 201 in the RV.  Hope this helps.

Nathan Larson, RV9E 200+ hours

Insurance is looking up.   Down from $3,133 to $1,750 and Falcon is still looking. People definitely need to join the EAA. It guarantees that you will be covered for first flight. I got a call on the way home tonight from the Falcon agent. AIG has quoted the same basic package at $1750.00 with some minor changes. The liability is reduced to 500K during the fly-off period along with the deletion of passenger liability during the period. All with a $100.00 deductible.

Regards, Larry Perryman

3) Maintaining your engine.

There are far more dealers and mechanics familiar with this engine throughout the world than you will find for any brand of conventional aircraft engine.   Parts are readily available and there is very little maintenance that you could not do for yourself

4) It is a problem to run these powerplants at "high" RPM and it will reduce TBO.               

NO.  "High" RPM is a relative term.   These engines were designed for sustained RPM in the range we run them, and in fact, much higher than we run them.   Racers routinely experience 8000+ RPM, whereas we rarely run higher than 5000 RPM and even then only for a few minutes.   In cruise, we run approx 3800 RPM which is roughly equivalent to a car traveling at 65 miles per hour.   Our takeoffs are roughly equivalent to a high-speed pass on the highway.   Our small, lightweight, well-balanced pistons and 7-bearing crankshafts make "high" RPM a non-issue.   We honestly don't know what our TBO (Time-Between-Overhauls) will be because we have yet to wear out a powerplant!    Regular oil analysis has shown no significant wear even after 1200 hours.   We will eventually establish a TBO recommendation once a few motors reach a point where their compression starts to decline.  We fully anticipate meeting our 2000-hour goal.   Besides, we have no intention of actually overhauling these engines because it is more economical to simply replace the block!   How many years will it take the average pilot to fly 2000 hours?   Chances are, we will have something even better to bolt up by then.

5)  These engines are heavier than a similarly configured Lycoming.

NOT SIGNIFICANTLY.  Because of the radiators and fluids, the base package is slightly heavier than an air-cooled unit.  However, fully configured, the entire package, including all accessories and propeller will be within ~5-10 lbs of a "typical" installation and well within the CG of most airframes.   The little extra weight of the block is recovered through our much lighter carbon-fiber prop.

6) It is "well-known" that automotive conversions are problematic.

NO.  That's the biggest myth of all!   Some of the misconception stems from die-hards that will forever insist on flying 1940's technology and have little or no direct experience with modern powerplants in aircraft.  Some of it stems from earlier days of independent trial-and-error testing of various ill-conceived conversions.   Much has been learned over the years and serious engineering has gone into these packages.  Eggenfellner sells only complete packages to assure consistently high standards of quality and safety.   Engineering never sleeps around here.  If we find a way to improve something, the improvement is implemented immediately.   We do the hard work so that you can enjoy easy flying.

7) Performance

Most pilots rarely fly their planes at VNE speeds and for those top-gunners out there, we offer a turbo version of the engine.   Study the performance data on the next page for a real-world example of what you can expect.  Much of our "performance" is also in related benefits of flying behind these engines, such as easy starting, hot fluids available for use in a cabin heater, smooth running, low noise, no mixture control, no primer, no carb heat and on and on.

8) These engines require battery power to run.

TRUE.  As do most modern, “electronically controlled” aircraft engines.   For this reason, our critically acclaimed Installation Guide walks you step-by-step through installation of a redundant electrical system.   It’s not difficult.  

9) Aircraft engines should have dual spark plugs.

NO.   Dual spark plugs are required by engines with large, low-compression pistons to promote good combustion (as is leaded-fuel).   These modern engines use small-bore cylinders / lightweight pistons and have advanced features to detect and prevent pre-ignition knock.  Mixture and timing are both electronically controlled.   It is very rare to see a failure of this system (we have yet to see one).    The system learns and adjusts automatically to your current fuel and flight conditions.  Some models require high test gasoline and other models use the lower grade so be sure to use what is recommended for your particular engine.  You can also use and mix with 100 LL.

Engine Package

QUESTION: The people at Vans say they do not recommended anything but the Lycoming for installation in their airframes...... Do they know something I don't, or is it just merchandising as usual??

ANSWER: Vans have a good reason to stay with what has been working for them before. This is why every RV is built from rivets and sheet aluminum and also why all RV models are very similar in design with only small changes over time. They discovered that modern performance did not have to come from new material and processes but rather by optimizing existing and proven technology. As far as engines, besides the full page ad they are running on the inside cover of Sport Aviation together with Lycoming to promote these engines and make money selling them, there is little incentive to recommend anything but what has been proven before.

QUESTION: Is the engine computer the same as the automotive??

ANSWER: Yes it is, up to 2004 model engines.  After this we use our own system.

QUESTION: How much does the firewall forward package weigh?

The H-6 engine has the same firewall forward weight as the IO-360.  The total is 350 for the engine and 420 for the firewall complete package.  Add 20 lb to this for a turboed H-6 model.

QUESTION: In the case of the RV6/7/8/9, the nose gear support is integral to the mount supplied by Vans, thus Eggenfellner has to either duplicate this in his mount, or cut apart the Vans mount to rob the nose gear section. Can anyone tell me how this works? Do I need to supply my dynafocal mount to Eggenfellner or do they build theirs from scratch?

ANSWER: You supply a mount for us to modify if you are not doing an (A) model kit, otherwise, we weld the entire mount. If you are building an (A) model, you are saving some money because the engine mount is included in our package price and it goes all the way to the fire wall, eliminating the need to purchase a dynafocal one.

QUESTION:  How do I know the engine has the HP claimed

ANSWER: We only claim less than what the engine was designed to produce in the car it was originally designed for

QUESTION: But the Subaru factory data is no longer valid as you have changed the intake and exhaust and perhaps other 'critical to HP' items. Not that these changes are harmful to HP, but they likely will change the HP and torque values over the engine operating range

ANSWER: Our flight testing also confirms the HP values.  The performance is equal or better than traditional engines. This, in conjunction with a basic fuel flow computation, will tell you how much HP the engine is making.

QUESTION:  What other advantages of the Subaru come to mind ?

MUCH LESS NOISE:  "When making short flights to the other islands or local demo flights. I have been cruising at 3800 engine rpm. The fuel flow is only 5.5GPH and it's so quiet it's almost spooky." Charlie Walker

REDUCED PILOT FATIGUE: This engine/airplane is a delight to fly and everyone I demo the engine to is very impressed with the smoothness and how quiet it is. Richard Herr  

REDUCED PILOT WORKLOAD: "My airplane is fully automatic with a constant speed propeller, automatic engine management, slaved GPS autopilot and so fourth. The program NASA is funding to simplify general aviation aircraft could save a lot of money if they just came to see my airplane:)  I don't have a carburetor heat control, no mixture control, no need to look at engine instrumentation (my instrument will tell me if something is out of limits),  no EGT or CHT gauges and on and on."   Bob Warfel

LOWER INITIAL COST: Jan, we had our local EAA meeting last night at my hangar and we had one of the largest turnouts for a weekday meeting that I can remember. There were probably close to 25 people checking out my engine. And all the comments were very positive. Everyone was very impressed with the engine, how smooth it ran, and the quietness. I am sending one picture along with this that shows a few of the men checking out your engine. I would encourage builders to take some time and add together everything they need in front of the firewall, all the way out to the tip of the spinner, for a Lycoming and also for the converted Subaru.  The real #'s are scary. Richard Herr

LOW MAINTENANCE:  I keep checking the oil before each flight, just doesn't use a drop and that is after 100 HR. When do you suggest I change the oil for the first time?  I'm using Castrol 5W-50 ,  Charlie

SAFE CABIN HEATING AND SAFETY: Use hot water heater and not a system relying on the exhaust for heat.  Don't worry about carburetor ice since you don't have a carburetor, low cabin noise and workload increases safety.

QUESTION: Two engines, both with say 175hp, one needs 5300rpm and the other needs 2600rpm to deliver the Max output. In order to get to the Max prop speed, the faster turning engine needs a reduction drive, the other drives the prop directly right? Is it true that with a reduction drive the torque of the output will be doubled if using a reduction drive with a 2:1 ratio? If yes then how would the torque on both engines compare? I have no idea about the torque a similar rated aircraft engine produces but if my theory is right, the auto conversion engine could have more torque at the same prop speed. This would allow a more coarse pitch on the propeller or even a larger diameter.

ANSWER: The torque on the air-cooled engine is derived through the long stroke and large piston. It is like hammering a nail, you either grab the big hammer and drive the nail in a few slow but heavy blows or you use the little one and tap it in little by little with fast light blows. In either case you set the nail in the same amount of time, hence you would have accomplished the same amount of work. Just using two different methods. If you elect to use the big hammer, you better make sure the surrounding structure can take the jolts.

QUESTION: How about fuel burn? I have seen listings by other auto conversion companies showing spectacularly low fuel burn. You're engines seem to use almost as much fuel as the traditional air cooled aircraft engines?

ANSWER: There is no free lunch. All combustion engine's are very similar in the amount of gasoline they use to produce a given amount of power. Some are slightly more efficient than others but this difference would be measured in ounces per hour and certainly not gallons per hour. To produce a given amount of horsepower, a given amount of gasoline must be burned. The formula normally used specifies how many pounds of gasoline is needed to generate one horsepower for one-hour. Most engines average about the same. The reason a Geo Metro automobile gets three times the gas mileage of a Suburban is not because the Geo's engine is so much more efficient but because the Geo only has to produce one third of the horsepower to propel the lighter car.

When someone tries to sell you an engine that claims both extraordinary horsepower yet incredibly low fuel consumption a red flag should pop up.  There is no such thing. You want power, you burn fuel.

However, that being said, the Eggenfellner Subaru / MT propeller combination, at reduced RPM settings. is a VERY efficient aircraft engine package and can cover large distances on very little fuel.  Any turbo or supercharged engine will need to run 100LL to prevent any possibility of detonation.

QUESTION:  What about weight?

We could all build our planes lighter if we really wanted to, but not
everyone is compelled to do so. I for one, love my creature comforts,
plush interior, extensive electronics and coffee warmer. It all goes
well with the theme of a smooth, quiet, modern powerplant. My weight?
1190 lbs. Do I care or need to pack light? Not at all!

Liquid cooled "automotive" engines are heavier than air-
cooled "aircraft" engines for obvious reasons that should be apparent
just by looking at one and thinking of why it was designed the way it
was. This should not be a difficult concept to grasp.

A liquid cooled engine must have a cooling jacket. This equates to
larger area in the cylinder head castings as well as water pump and
related drive mechanism, thermostat, hoses, radiators, coolant
reservoirs, heater cores and fans, etc. Because modern engines are
computerized, we require a rock solid electrical system that calls for
dual batteries. Because small-bore automotive engines require higher
RPM to achieve max hp & torque, we require a gearbox to reduce the RPM
to something that can drive a prop without shattering. Modern engines
use overhead cams, not pushrods. These are the primary factors
leading to a heavier overall engine. However, we make up for
this weight by using modern light-weight carbon fiber propellers. We
can run these props because the end result of our
powertrain is far smoother than a Lycoming (as witnessed by anyone who
balances our props or flies in our planes). These same props are not
allowed to be used on Lycomings because their direct drive impulses
would shatter the blades.

 

QUESTION: I live in Texas so most of the summer it's 100+ are there any cooling problems?

ANSWER:  An adjustable cowl flap should be installed if you live in such a hot climate and enough cooling will not be an issue.

QUESTION: I noticed that the cooling radiators are smaller and thicker than their automotive counterpart. However, it seems that the total area of both is so small that the extra thickness could not compensate for the loss of area. What kind of "magic" were you able to work so you can run cool in the hot (100+ degrees) Texas sun?

ANSWER: Small radiators but BIG fan (propeller).

Torsional resonance can safely be dealt with.

Electric motors and turbine engines don't have these problems because they generate their power smoothly and not through a reciprocating motion as in a combustion engine. So the first step is to get closer to the smoothness of a turbine. This can be done in several ways and this is how we do it: 

Use an engine with a short stroke and relatively high RPM. This places the power pulses closer together so power is generated through many low inertia pulses rather than a few heavy blows.

Use a relatively heavy flywheel with most of the mass along the outer perimeter. Bolt the flywheel to the crankshaft of the engine so that it will produce massive amounts of inertia while spinning 2.02 times faster than the propeller. This will further smooth out the engine pulses. We now also use a very specific, torsion dampening flywheel.

Use a propeller with low blade weight. The Subaru is so smooth that carbon fiber propellers can safely be used. Some of these props would shatter on a traditional engine. The low inertia of the propeller blades is no match to that of the spinning flywheel. The drives have thousands of test HR on them and have been flying in airplanes for 15 years.

Forgive my layman’s description.  I am just trying to hit the major points (plus I've got some time to kill this morning).

First, consider the forces involved when you bolt a heavy prop directly to a crankshaft driven by several very large pistons.  A prop can be modeled as a solid disk mass when spinning.  One of the critical factors in sizing a prop is maintaining tip-velocities just below supersonic.  Thus, the disk is typically as large as it can be (ignoring for this discussion other practical factors such as ground clearance and available torque).  A large rotating mass will produce substantial gyroscopic and acceleration forces and transfer them directly through the crankshaft.  Additionally, each cylinder produces a sharp energy spike when it fires.  The spinning prop mass helps to absorb these spikes, but this of course further stresses the crankshaft as it alone must transfer the spikes to the rotating mass.  More cylinders typically equates to a smoother engine because these spikes occur at closer intervals.  Thus the prop does not need to accelerate then decelerate as much between firings.  Without the added mass of a flywheel, balancer, and the prop, no engine could survive this abuse for very long.

Our Subaru's are different (better) in many ways.  First, the pistons are much smaller, producing less of a spike at each firing.  Of course this means we have to fire more often to produce similar horsepower (thus our higher RPMs).  A side effect of smaller pistons is that we have a cute little crankshaft with closer rod spacing and thus shorter overall crankshaft length.  Next, Subaru uses more and closer spaced main bearings than Lycoming, helping to minimize crank deflection and overall bearing wear.  Next, our crank is connected to a dual-mass flywheel-within-a-flywheel (recent upgrade).  The inner flywheel is isolated from the outer one by a series of springs, which further absorb firing spike vibration.   Finally, we spin a very lightweight prop where the gyroscopic forces are decoupled from the driving forces via the PSRU.  In short, the prop is not directly bolted to the crankshaft thus its forces are not entirely transferred to the crankshaft.  Even though we use automotive engines which might not fare well if we bolted a prop directly to their crankshafts, our PSRU is built to absorb the unique prop forces and isolate the crankshaft from the most damaging of these forces.

Our most critical issue is minimizing prop imbalance.  Since the major prop disk forces are transferred to our PSRU, a well, balanced prop is essential for long PSRU life.  I flew for a year before we all realized how important this is.  I was so pleased by how smooth my plane was compared to the spam cans I had flown that I had no idea anything was wrong until I took Jan for a ride one day.  The very first thing he said was "you need to balance your prop".  After balancing, the difference was astonishing.  I have a detailed graph showing the before and after effects which I will be happy to show anyone who asks at Oshkosh.  

"We are smooth, ask us why" 

Have a smooth, stress-free day and may the forces NOT be with you ;^)

Gary

Reliability

QUESTION: I enjoy cross country skiing. Often this means starting my LYC when it is around zero. I am always worried about the availability of pre heat. I understand the advantages of liquid cooled engines in cold weather operations. My question is what about cold weather starting with a Subaru ? What type of oil is used in a Subaru engine?   Mike

ANSWER: We use  a 5W-30  in the Eggenfellner Subaru.  It starts exactly the
way a Subaru car starts - every time.  Subaru also have a 110V block heater available in their accessory catalogue if you want to keep it plugged in :)

QUESTION: I, too, would like to know if the Subaru, in Jan's configuration, has been run on a Dyno for an extended stress/torture test (48+ hours non-stop high RPM). If so, I'd like to see the results.

ANSWER: I used to spend my weekends doing that kind of testing in NH. I don't think you could hurt the engine if you tried really hard because we tried. It is so overbuilt and balanced that if you (and this is the key) keep it cool and feed it oil and electric, it will go for a long time.

The variable valve and ignition timing, working together with the knock sensor, will not let you put more stress on the engine than it is designed to handle. They run Subaru's in Rally cars, close to the same exact engine, with over 400 HP. This does not say much for how long it will last but proves the crank and case to be plenty strong.

The best test is an engine, a propeller and several weekends with a thermos and sandwiches for continuous running. We had one prop strike on a Glastar airplane, it cut up another airplane and bent the prop but didn't do a thing to the engine or gear drive.

We ran the engines for days straight to prove the gear drive with heavy metal props and to verity the power settings. Nothing got hot, showed any sign of wear or otherwise deteriorated.

The best assurance to know if this works or not is still to talk to someone flying one.

QUESTION: What is the estimated TBO?  The Lycoming is typically about 2000 hours, which is considered a long time for small aircraft engines of this class--but when I compare it to a car engine, it always seemed a bit short. Is this short TBO a result of the basic problem with air cooled engines or is it a result of the very conservative safety requirements necessary for airplanes?

ANSWER: 2000+ hours.  Air cooled engines have a shorter life expectancy.

QUESTION: As the manufacturer of the plane what is my liability for using a non aircraft engine?  Can your company survive a case like this and continue to support us?  

ANSWER: You are totally responsible for choosing the engine for your own airplane. You have to do enough research to be reasonable certain that the engine you choose for your airplane will satisfy the requirements you have for your airplane. This applies to the aircraft kit you decided to buy, the electrical wires you are using, the seat belts you decide to use and so fourth. The company or individual selling you the cotter pin for your landing gear attachment nut at the local hardware store, that failed during landing and then got you hurt is not responsible for your accident, you decided that these part would serve your aircraft project and then went ahead and installed it. Nor were the person that sold you the part present to observe if you installed or maintained the part correctly. You will have to sign a statement to this effect if you buy an engine from us.

QUESTION: Why not use two separate Electronic Control Units for the engine

ANSWER: On engines of modern design, ignition systems are manufactured with no moving parts and have very high voltage output for a strong and clean spark. Spark plugs are unlikely to go bad or fault like they do with the low voltage magneto systems.

As far as redundancy, the necessary electrical power for this system to work, is provided through dual and independent battery systems. A coil is used at each spark plug so that if one is lost remaining cylinders stay working for partial power operation. The electronic part of the system is placed within the aircraft itself and has backup circuitry within to keep things working even with partial failures. However, there is no such thing as completely independent electronic boxes for the simple reason that it makes the system less reliable with the additional required wiring. Electronic systems are not 100% full proof, but they are good. When they fail, it is usually not after the engine is running and at operating temperature but rather after an idle period or from the lack of electrical power.

It comes down to what is the safest approach to the problem at hand.  In this case the decision of the designer, me, to opt for a simpler, rather than more complicated approach to the task of operating the fuel injection and ignition system of the Eggenfellner engine in an airplane configuration.  And making this decision on the belief that it is a more, rather than less, reliable approach.  Obviously, anyone that would like to use this engine in their airplane would have to share this view.  Automotive ignition systems have been getting better every year and failures, due to the system itself having flaws, are not at all common.  Also, some automotive manufacturers have a better track history than do others.

As is the case all over an airplane, many parts do not have backups.  There is no backup to a throttle cable binding, an exhaust pipe breaking and putting something on fire, the wing spar buckling, the propeller failing, the control stick come off, the cables binding, pulleys or push pull rods moving the controls failing and so on.  Any one of these items failing is a likely disaster.  As humans we tend to trust these components because we feel that something mechanical, something we can see and touch is less prone to failure than an operation done through electronics with no visible and moving parts.  Modern automobiles have proven this to be completely wrong.  Cars usually don't need to be brought back for service for 100,000 miles, a far cry from the days of mechanical distributors, magnetos and carburetors that needed constant attention to operate.

So why not just throw in an additional ECU.  Because the additional complexity of wires and a switching device would be far less reliable than the original system.  The ECU does have multiple circuits for it's own redundancy.  Car manufacturer are interested in keeping their customers happy and go to great length to make the car drivable even after some fault might develop.  A tested and proven ECU has no reason to just suddenly go bad, like I said, there are no mechanical devices that can wear out. 

The likely failure modes are in the installation wiring, the grounding and the backup battery circuit.  Something as simple as neglecting to install a redundant electrical system is very serious.  Or to not provide the pilot with a warning if the alternator goes of line.

The only mechanical parts to the system is the fuel pump, the alternator and the fuel injectors.  The alternator failure is guarded against by keeping a backup battery fully charged through it's own charging circuit and with it's own Volt meter.  The fuel pump must have a backup pump and be wired for automatic switchover if one fail. (See the installation guide pages)  The injectors are unlikely to all fail at the same time so we take the risk of partially or completely loosing one cylinder for reduced power operation. 

The ECU should be mounted inside the airplane, should be shock mounted (even though hardly any vibration exist) and the system should have multiple power sources and multiple grounding paths.  There should also be a last resort backup circuit bypassing all battery contactor relays and provide direct current to the ECU and one fuel pump for operation of the engine after power is lost due to a system malfunction other than the battery itself.  In other words, it should be wired according to the installation guide on this web site.

I worry about all of us staying as safe as possible, obviously, for those that do not agree with the design criteria, this is not the engine of choice.  There are simple systems available that in theory could be made to run the same injectors and coil but again they would have to be switched into the system mechanically, making the 2 systems less reliable. 

The dual mags on traditional engines do provide a way to fire 8 plugs on a 4 cylinder engine. However, they are driven by the same mechanical accessory case on the engine. If you follow the "dual" system redundancy, then it has to be truly redundant. They should not ultimately end up in a single point of possible failure. We don't wire the 2 fuel pumps to the same battery, we don't even ground them to the same terminal. If the 2 magneto's were installed because it would give true redundancy to the ignition system, then why are they driven by the same gears and the P-leads brought to the same switch where an internal mechanical breakdown would shut down bought magnetos? The dual mags are there because  the engine needs dual spark to operate efficiently. Not only are the mags mechanical but the internal coils are absorbing all of the heat from the engine, making their life span short. It's like the idea of having two engines running a single prop through the same prop drive. The single point of failure would be the drive and if one engine failed, it likely would take the other with it. Many engines even have a single housing with 2 mags and one drive gear, now where is the redundancy in that?

By finding out what is likely to fail, we provide backup, but to back up on everything is impossible, expensive and likely would complicate and render the system less and not more reliable.

Keep in mind that we are using ECU's that are continuously being improved upon by designers that care about that the cars they design for keep running. Cars are rated by how often they have to return to the dealer for service in most auto magazines and consumer report. It is not true that Automotive electronic designs are fragile and don't go through the destructive testing of lets say military avionics. The mass production of these components allow for excellent manufacturing techniques that only large volume production can afford.

QUESTION:  Are Subaru Aircraft engines for everyone?

ANSWER: "I am one of the RV9'ers committed to using the Subaru. I've asked the same questions and am satisfied with the responses, though they are not yet backed up by scientific studies. Come to think of it, if you investigate the RV9's brief history, it's crash rate is rather high. The point being, this is the very nature of "Experimental" aircraft construction. You as the builder are entirely responsible for making the myriad decisions regarding your own safety margin. If you want well proven historical evidence, get yourself a Cessna. If you are confident that you can build an airframe that is satisfactorily safe, but you don't have the confidence to assess the safety of your engine, get yourself a Lycoming. If you are willing and able to help the quest for competitive engine development, Subaru's are an excellent choice. "            Gary

I fly behind the H6 (don't sell them), like it, and report what I see.

This morning the RV broke ground before the second hash marks on runway 8L at KSUS with the ATIS wind at 050/07.  I believe those marks are at 500'.  This was not imagined.  It  happens on every flight unless full of fuel, heavy with stuff and it is hot.  (Also, I am seeing more and more 150 mph at 6 gallons burn.  This I do not understand as it had been running around 143 before the trip to SNF.  It could be the new gear reduction and fly wheel are more efficient than the original as these items were installed at Jan's during that trip.  Or it could be a regular diet of 93 mogas...?)  

If, for anyone, the information published on this forum by guys flying these engines, and on the Egg web site, is insufficient, perhaps Lycoming would be a better choice for that person.  Some have a need for EVERYTHING to be cut and dried as in a Cessna or Piper and Lycoming.  This you will not find here.

What you will find here is an effort to make these engines run better and better.  It is an ongoing process and anyone interested in joining the effort is welcome.   

dd   
 

Installation

QUESTION:  How do I best prepare the airplane while I am waiting for the engine to arrive?

ANSWER:  Consult the installation manual now available.  It has an entire chapter on this :)

QUESTION: You list the output rotation as traditional clockwise. Is this correct?

ANSWER: Yes, the propeller rotates c/w as seen from the pilots seat. This is standard in most airplanes.

I weighed the rebuilt RV-7 today with the H6 and the Felix fixed pitch wood prop.  Weight = 1175  CG = 77.43  I ran a preliminary weight and balance situation with full tanks and 360 pounds of pilot and passenger.  The gross weight came in at 1787 and the CG at 81.83, which is 3.1" aft of the forward limit 78.7".  It would appear the H6 is just fine for the RV-7 or 7A with its CG range of 78.7 - 86.82 aft of datum.  I have no way to transpose these numbers to a RV-9 or I would, however, it is my gut feeling it will be OK with a light prop.    The RV-7 with the H6 probably will be OK with the MT prop also.
  dd

Operation

QUESTION: How long will the engine continue to run after an alternator failure, assuming minimal       electrical accessory usage.

ANSWER: With 2 batteries you have more than 1.5 hour. Plenty to find a place to land. If you need more, just install a larger battery. The drain is about 7 A for one fuel pump and the ECU at partial power.

What oil / fuel should I use with my engine?

The 4 cylinder, non supercharged engines, can operate on 87 octane car gas, or 100LL with the recommended amount of Marvel Mystery Oil mixed into the 100LL, as shown on the label.

Six Cylinder engines are high compression engines and therefore MUST use high octane fuel (91 octane or above)  100LL is also good if Marvell Mystery Oil is mixed with the gasoline.  This requirement is also for any turbo or supercharged engine.

Oil, for all engines should be 5W30 or 5W40 weight.  Use regular oil if you use 100LL fuel and not full synthetic oil.  You can use synthetic oil, after a 100 hr brake-in period, only if you do not use 100LL fuel. 

Please read and understand all operating instructions for this engine in the Subaru maintenance and vehicle operations manual.

QUESTION: If my car ran at 5600 RPM I would be concerned. The Subaru is essentially an auto engine even after it has been converted for aircraft use. Should I be concerned about this?

ANSWER: We don't operate @ 5600 RPM but high RPM is an excellent way to get power from a well balanced engine with a short stroke for a short duration such as for takeoff and initial climb. In the H-6 engines, we get plenty of power @ 4900 RPM. This RPM is used for takeoff and climb. Then 3200-4200 RPM is used for cruising.

The Subaru is no ordinary car engine. There is a main bearing every 2 inches and this, together with a balanced flywheel and lightweight pistons, provides for an easy turning engine. It is not a coincidence that we only work with Subaru engines. Drive a Subaru and wind it to its redline of 7,000 RPM, it will be smooth as silk and you will understand that 3200-4200 for continuous use is not a problem.

Be careful not to dismiss this wonderful engine before getting all the available information. If you get to fly in one before making a decision I think you would prefer an Eggenfellner Conversion over a traditional engine.

Eggenfellner Aircraft Inc is here to stay, we have been doing this for 16 years and thrive on making sure each customers modern airplane becomes a flying success with a modern engine up front.

Overhaul Cost

QUESTION: You mention that I can get spare parts for the engine from my local dealer. This is a VERY good thing. However, you must have made some modifications or designed/manufactured some additional parts to adapt the engines to aircraft use. Are these parts available from you?

ANSWER: Anything not from a local dealer is made here and can be purchased here or duplicated by any welding or machine shop. 

QUESTION: What is the TBO (time between overhaul) of the reduction drive and the cost to overhaul it?

ANSWER: The TBO is 2,000 hours and the overhaul cost is $2,000.

QUESTION: Do you have a recommended engine monitor that works with your engine? Your website has a picture of an RV-9A with its instrument panel. It appears that in addition to two automotive gas gauges, there is some kind of engine monitor. Who's is it?

ANSWER: We recommend the Grand Rapids Technologies EIS monitor and also the EXP bus Control Vision Corporation dual electrical panel. (Please see "suggested products" section of web and the installation manual)  They also have a wonderful EFIS system now available.

QUESTION: Does it make sense to have two alternators or just go with two batteries to provide fail-safe backup for my all-electric panel? Is 50 amps from the alternator enough for an all-electric panel?

ANSWER: We run two batteries and a single alternator

Aerobatic

QUESTION: Also, how does it perform inverted, or in a steep angle at low G's ??? Would simple aerobatics like a roll or loop cause problems like oil feed?

ANSWER: You can do simple aerobatics like you describe. The only engines that can spend time inverted are those equipped with a dry sump type of oil system. The Lycoming don't come with this but can be equipped with it for additional money. The Subaru does not have this system but has three layers of baffles in the oil pan to keep the oil away from the spinning crankshaft. Inverted flight is however limited to positive maneuvers including loops and rolls but no inverted flight beyond a few seconds. The oil pressure will start to drop at that point.

Propeller Options

QUESTION: Will your engine package accept a fixed pitch metal prop? Do the flange holes line up? What difficulty can I expect?

ANSWER: The bolt holes do line up but metal propellers can not be used.  They are far too heavy for any airplane but are able to handle the direct drive pulses from a traditional engine.  On the smooth Eggenfellner engine we use an adjustable (constant speed) composite propeller with great results and half the weight.  You can also use ground adjustable propellers.

QUESTION: Some of us builders who are interested in your engine package would like the simplicity of fixed pitch props (ground adjustable), is this type of prop a viable option to use with your engine package on an RV? What are the performance issues??

ANSWER: The advantage of a constant speed propeller is greater on the auto converted engine due to the large RPM range available for flight.

The airplane will fly with a fixed pitch cruise prop but will have reduced climb performance.  The H-6 engine has enough power to generate max allowable HP in the RV-9A with a fixed pitch propeller.  We now offer a 3 blade Sensenich ground adjustable propeller for these applications.

I'm concerned about using Jan's prop balancer tool. If my engine gets any smoother, I may not know if it's running or not :)
Robert .....   P.S. See many of you soon at Osh

TECHNICAL QUESTIONS

1. A new bearing was added to the center of the flywheel to accommodate a stub shaft from the "adapter shaft" for what appears to be side loading? Was / is that an issue with the old box? What bearings did you use inside the new box, ball or roller bearings, both?

The bearing you refer to is identical to a clutch pilot bearing used with a manual transmission car. This small sealed bearing does not turn but does move slightly when the torsion damping flywheel is exercising it's damping function. Its function is just to center the splined drive shaft perfectly on the crank centerline. From your description, it sounds as though you were working on an engine with a solid flywheel, and in that case, the bearing is only used for centering purposes during assembly. The new drive exclusively use ball bearings. To support the input gear, G1/G2 drives had a single input bearing and an internal roller bearing to the gear. G3 drives have two different sized ball bearings, spaced apart, on the outside of the input gear and a single ball bearing internal to it. Side loading is not the issue in this area. Creating a system with plenty of support, easy oiling and large enough bearings to handle the impulses from the engine, yet small enough for the RPM is the key. These are the fastest tuning bearings in the drive unit.

2. While the "engine mounting plate" appears stout enough, have you measured for "flexing" under the sever gyro force load of the spinning prop? Is that where side loading may be developing?

You are confusing the entire plate with what happens inboard of the bell housing perimeter. The plate is bolted in 10 places around the bell housing, effectively making it one with the housing. Then, only 1" inboard, the structure from the aft drive section, further reinforce the integrity and assure consistent alignment of the drive input shaft to the crank centerline. We have tested this by flexing the tip of the plate forward 4" with less than 0.001 deflection inboard of the bell housing perimeter. Many mistakes this plate for being very heavy. In fact it is not. The weight is only 7.5lb and provide the engine with an engine mount, gearbox mount, starter mount, oil cooler mount and cooling system mount. the plate is reinforced by traditional aircraft triangulation, using 4130 N steel tubing.

3. What temperatures rises (over ambient air temp) should a new Gen 3 gear box see during break-in and normal operation?

There is no brake-in period. The temperature should remain 15 F below the engine coolant temperature. Max engine coolant temp. is 220 F. Enough air cooling of the drive should be provided to maintain this ratio. The spinner to cowling gap is directly related to the temperature of the drive unit and a 1/2" gap is preferred over a smaller gap. This also allow for easy cowling installation / removal.

4. Do you suggest having an oil analysis done at regular intervals? Do you have any base lines for "normal wear".

Yes, send in a sample every 50 or 100 hr. The company you send it to will provide a guide for normal wear. What you are really looking for are trends, comparing your first analysis to the next, to the next.

CAN I MAKE CHANGES TO MY ENGINE:

No, you can not.  Someone recently asked about changing the Engine computer.