Who's Flying With A Subaru

CLS447

Platinum Member
Joined
Oct 30, 2003
Messages
6,324
Location
Reading, PA
Aircraft
Air Command 503 & Air Command SxS /EJ2.5
Total Flight Time
Aprox 400 gyro
There's been some discussion about Auto engine conversion reliability.

Anyone want to share their thoughts on their Subaru engines.

Ask the guy who flies one !
 
I have flown suburas for many years,had the second subura on a gyro,aea81 from a "brat" flew that little engine for about 400 hrs. Changed to a 100 hp direct drive before I "put on" a bunch of pounds! Installed a sub four redrive and have a bunch of hours on it before the fuel pump quit. Am slowly rebuilding. Can't say enough good about them.
 
Chris,

I flew almost the exact number of hours as Stan did on 2 RAF's. Never once did I have an engine problem.
 
Love mine, never had a problem but I don't have many hours yet. I do know that there are probably way more hours flown with Soobs than what we can probably imagine. I'm very fortunate here in that we have Dr. Subaru (Don Bouchard) in our club.
 
I have a Sub EJ22 on my Tandem Air Command. Runs nicely. I had some engine fluctuations at 4300 RPM, but that resolved after some of the fuel lines were changed.
 
I was flying with a Soob...'till it got real noisey and then really quiet.

I will again soon, though. It wasn't really the engine's fault. Rather, I fault the re-drive as being inappropriate for an EJ series engine. Can't do side loads on an EJ crankshaft. Bad things happen.
 
Running an EJ22 with carb on my RAF since 1999.
Easy to work on, easy to get parts & faithfull.
 
my 2nd gyro was ea81 soob powered, that was 30yrs + ago, used nothing but soob ever since, last one was ej22 soob ......all never missed a beat. About to fly my new build fitted with an ej25 soob ........down side, they all weigh a ton.
Rotax 4 bangers........simply the best tho
 
Wow.....keep em coming !

In my world, I don't need to buy a 900 series Rotax. Their exhausts cost more than a Subaru engine !

But then I don't drive a Mercedes either !

BTW....yesterday I finally registered, insured & had inspected, My new(to me)2000 Subaru Outback Wagon ! Found her on a lot about a year ago but I just put her in the garage. 131,000 miles & a little dusty from sitting......VERY NICE CAR, hope to have her for the next 20 years ! The Local Soob dealer has all the maintenance records for her.

The last owner really took care of her ! Now it's my turn.

I am hoping this great weather keeps up, I don't want any snow, The Soob can easily handle it but I don't want to drive her through the salt !

It's like my first new car ! The 88 wagon is now to be used on the farm.

Here is a pic of the 88. I transfered the plate over to the new car. I scraped the old registration stickers off the plate. I had her alot of years & gave only $800 for her. Even drove her to Mentone one year !

Not bad for an EA82 !
 

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People that are happy with their auto-conversions are more likely to post about their experiences then those that are not, for a number of reasons.

Anecdotal postings are of almost no real value when it comes to experimental aircraft.

Soobs have caused me to experience 3 unplanned landings.

There would have been a 4th but I caught the fact the re-drive was self-destructing before the next flight.

1 downing was from a 250hr EJ25. The oil pickup tube broke off from vibrations and landed in the pan. Engine showed no sign of problems then the oil pressure dropped to zero. Thirty seconds later we were in a farmer’s field looking at a toasted engine.

I had NEVER heard of this happening before but once I started asking around I found quite a few people had experineced the same thing.

With an aircraft engine, a flaw or issue would never become this common without a service bulletin being issued.:sorry:

Once again, people do not like to post, talk and brag about failures in experimental aircraft, but they do like to go on about successes.:humble:

2 downings were from issues with the RAF carb adaption for EJ22's. NEVER fly a carb 2.2 L without EGTs! They will go lean and warp the exhaust valves.

The almost down was from a improperly hardened gear in a planetary redrive. It turned itself into shavings and since the redrive shared oil with the engine it ruined the engine as well.

I do have 2 soobs in my shop and I hope to be flying one again someday if I can find a partner to help me with my 2 place project.

My take on soobs in aircraft..

1. :DAfter conversion and successfully flying about 100 hours chances are your soob will be quite dependable, affordable to fuel, cheap to maintain.

2. To my knowledge there is no better "bang for your buck" than a EJ22 or EJ25. However, if you have the money to spend on a purpose built aircraft engine you should buy the aircraft engine.

3.:( Redrives seem to be the big issue. They are expensive, heavy and are often less reliable then the engine. Also, some such as the belt redrives can put undue pressure on the crank bearings.

4. People should not confuse soob reliability in situ (in the car) with reliability converted to aircraft use.:boink:

5. The EJ-22/25 engines provide the ability to power a 2 place gyro for 1/3 the cost of a used purpose built aircraft engine. This opens up the possibly of aircraft ownership to a much larger fraction of people, especially those entering the sport.

This is an invaluable contribution to our sport.:first:

6. :confused:Converted auto engines of any kind do require an understanding of maintaince and willingness to tinker that is greater than many people realize and for people that enjoy pilotage but NOT tinkering this can actually turn people away from the sport and introduces a risk factor.

Sometimes auto engines are turn-key solutions but many times they are not.

7. While auto engines have a solid place powering 2 place gyros I would NEVER recommend a converted engine for a single place gyro. The exception to this would be simply for someone who has built the aircraft for the experience of tinkering, but not for serious pilotage.

Rotax engines that can power single place machines are a much lighter and better choice then small auto engines for single place gyros. Used Rotax engines fall into a close enough price range with auto conversions to make them a better option.

8. My number 1 gripe :mad: is seeing people proclaim that a converted auto engine, especially one that has not been professionally converted by a highly experienced conversion shop or individual, is as reliable and "safe" as a purpose built aircraft engine.

:director:These proclaimers try to divert common sense with anecdotal examples which does a great disservice to those fooled.:lie:







my 2nd gyro was ea81 soob powered, that was 30yrs + ago, used nothing but soob ever since, last one was ej22 soob ......all never missed a beat. About to fly my new build fitted with an ej25 soob ........down side, they all weigh a ton.
Rotax 4 bangers........simply the best tho


Well said.

There is a reason why Soob rebuilders have never put a dent in the Rotax >100hp market.

Apples and Oranges.

Long live the soobs! (and long live the ablity for gyros to make zero-roll engine out landings!)

.
 
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UH..Yea

UH..Yea

Just replaced the oil pickup tune on my Sparrow Chicken last week.. ( No problems with the factory tube) But frame of mind is as needed as good equipment....
Bitta cutting and bunping on the pan internals and You Be Dunn..Be sure of what year, model, and engine you have will help that problem out too.

Sorry to hear about your engine outs Tim.. And as always..

Have a Place to go IF The Engine Lets GO!!

Sounds like you had everything under control ..
.Neva Doubted you for a second.

Steve
 
I was flying with a Soob...'till it got real noisey and then really quiet.

I will again soon, though. It wasn't really the engine's fault. Rather, I fault the re-drive as being inappropriate for an EJ series engine. Can't do side loads on an EJ crankshaft. Bad things happen.

"It wasn't really the engine's fault.."

If we could just run on the soob CORE.. that would give us amazing longevity!

There in lies the problem. The EJ25 cores have problems with oil pickups, head gasket leaks and other issues..

BUT the EJ22 core is amazing but we can't just run them that way.

We have to put on a redrive. The redrive harmonics, stresses and just plain reduced reliability make every conversion an unique experiment.

Every non-stock Subaru piece critical to keeping the engine running adds another non-aircraft grade point of failure.

It's is not about 'driving a Mercedes' it is about aircraft grade reliability and the COST involved in obtaining this measure of reliability.

You don't buy an aircraft engine to brag you have a Mercedes under the hood, you spend that money because there is an associated VALUE.

I have to roll my eyes when people boast about having 500 or 1000 or 2000 hours on a converted auto engine.

Especially belying is when they say "it made it to.." (like it was crossing the finish line of a triathlon)

The only reason that is impressive is because it IS a conversion.


Saying you have 2000, 4000 or 5000 hours on a Lycoming impresses no one because it happens so often there is likely an engine with these kind of hours in almost every little rural airport.



Yes, I fly soobs but not because I am fooling myself into thinking they are a replacement for aircraft engines but because they are a low cost alternative to aircraft engines.

Understanding the difference is critical.

It has nothing to do with wanting to 'drive' a Mercedes over a Subaru. It has to do with the extra 5-10 grand I don't have in my bank account.

Just replaced the oil pickup tune on my Sparrow Chicken last week.. ( No problems with the factory tube) But frame of mind is as needed as good equipment....
Bitta cutting and bunping on the pan internals and You Be Dunn..Be sure of what year, model, and engine you have will help that problem out too.

Sorry to hear about your engine outs Tim.. And as always..

Have a Place to go IF The Engine Lets GO!!

Sounds like you had everything under control ..
.Neva Doubted you for a second.

Steve

So true!!

ANY engine will put you down!

No engine ever made is infallible!

.
 
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We are a small group , Tim......I think 100K gyros will make us a smaller group.

Bensen had the right idea.

I got into this because it was real & I could afford it. Even the price of most new single seaters these days make people hide their wallets.

I still believe it is all about affordability or maybe we would all be flying helicopters.

I am just saying that YOU CAN AFFORD TO FLY A SUBARU ! That's all...

I also love my Rotax 503.

Does anyone ever ask you....That is so cool, How much does one cost ?

End of game for the type of people who would really do it if they could afford it.

Remember those days when you could get a complete RAF kit for about 25K ?
 
We are a small group , Tim......I think 100K gyros will make us a smaller group.

I still believe it is all about affordability ...

5. The EJ-22/25 engines provide the ability to power a 2 place gyro for 1/3 the cost of a used purpose built aircraft engine. This opens up the possibly of aircraft ownership to a much larger fraction of people, especially those entering the sport. [/FONT][/COLOR]

This is an invaluable contribution to our sport.:first:

That is one of the main points I was trying to make.

Cost savings IS the reason for air-soobs.

If soobs did not save you $5-10K there would be no soobs flying, they don't compare to purpose built engines.

I still believe it is all about affordability or maybe we would all be flying helicopters.

Not for me. If I had unlimited funds I am pretty darn sure, I would have a twin turbine powered 6-place, jump take-off gyroplane with Larry Neil's landing gear.

Helicopters are too tiresome to fly and require too much pilot input for relaxing cross country or sight seeing.

Plus, you have to convert to autorotation, watch out for ring-vortexes/settling with power, you blow the crap out of everything with rotorwash...

No thanks!
 
Reliability----This brings up some really good questions and considerations about re-drives. Your basically have 3 types,---- belt, planetary gear, and spur gear.

The planetary has essentially no offset radial load on the crankshaft because the power transfer in the reduction is thru the planet gears and is equal in all directions. The spur gear has a radial load factor due to the power being transfered from one side of the small gear to the large gear, but a lot of this is compensated for by the 2 bearings on either side of the spur gear and its precision alignment with the crankshaft which actually moves the thrust point to a vectored angle as opposed to a direct up and down load. If one is using a centrifugal clutch then the radial load is also greatly reduced. The belt drive probably has the most radial load of all the re-drives, but it too has an outer bearing but uses the rear bearing of the engine as the "other" bearing supporting the lower belt sprocket and thus you are playing with about .002 (or less) of oil clearance plus you are also flirting with crankshaft deflection if it is not DEAD ON CENTER.

This means that if you have any deflection (even a little bit) you are causing the crankshaft to flex every time it revolves. Eventually the shaft will crystalize and break at the rear main bearing of the engine, you will know what caused it when you look at the break, it will be as clean and even a if it were cut with a laser. I have seen 2 such breaks one on a EA-81 and one on a EJ-2.2

So now comes the part a lot of people overlook. Let's say you have a re-drive that is NOT a planetary and you are going to jump the HP quite a bit. No problem you think because you know the re-drive is rated for the higher HP and the engine is capable of the power boost.--- so where is the problem. The problem is you are going to increase the radial load on the rear main bearing, maybe to the point of causing crankshaft deflection or reduced oil clearance. The end result is clear, but did the engine really fail,-- no, the failure was the lack of understanding of the features of the re-drive. I saw a video of some of the testing Subaru did on their EJ series engine in the car on the test track, they were down right murderous and--- no failures. Most of the failure of our converted engines is not engine failure, it is CONVERSION FAILURE !!!!!!!!!!!!

Tony
 
Thought I posted earlier but there's no post there so unless I have been deleted for some reason, I will have another go !

My suby 2.2 EFI with a rotax gearbox & 76 inch prop has around 3700 hours, with one engine out caused by a cam belt idler evacuating the engine :eek:.
Since then, the idlers get replaced every 1500 hours.


The GA Lycomings / Continentals out here have to bee re built at certain hours and they have plenty of failures well before 2,000 hours.
 
For what it's worth....my Continental IO-470-N engine had about 600 hours since overhaul when it decided to take a crap.
 
My 2 1/2 cents on Soobs:

I flew 3 SHs with EJ-22 engines. First two were with engines converted by CCR and the only thing with them was once when cam belt idler bolt went out into belt's plastic cover and almost broke the cam belt. I felt strange jerks and found the problem before it reached the big wallet.
Third SH' engine was likely rebuilt by AAI and I had an engine out on it after ca. 30 hours when flywheel left it's place (loosen bolts) seconds after take-off. Next problem was when generator support broke - its' rodends appeared to be cheap Chinese and broke like a glass some hours later.
After that engine worked OK for some hours, I didn't see this machine from that time just heard it flies.
I had one more engine out with Soob on that yellow tractor we tested here. My guess is that a mechanic who prepared the engine made something wrong with cam belt tensioner (guy worked with it just before that flight), cam belt jumped through some teeth so pistons and valves clashed together on a downwind leg. Landing into a plowed field was OK.
All in all Soobs themselves didn't make anything bad here.
 
Just replaced the oil pickup tune on my Sparrow Chicken last week.. ( No problems with the factory tube) But frame of mind is as needed as good equipment....
Bitta cutting and bunping on the pan internals and You Be Dunn..Be sure of what year, model, and engine you have will help that problem out too.

Sorry to hear about your engine outs Tim.. And as always..

Have a Place to go IF The Engine Lets GO!!

Sounds like you had everything under control ..
.Neva Doubted you for a second.

Steve

Steve, Thumbs up or thumbs down for the Subaru ?
 
Reliability----This brings up some really good questions and considerations about re-drives. Your basically have 3 types,---- belt, planetary gear, and spur gear.

I saw a video of some of the testing Subaru did on their EJ series engine in the car on the test track, they were down right murderous and--- no failures. Most of the failure of our converted engines is not engine failure, it is CONVERSION FAILURE !!!!!!!!!!!!

Tony

BINGO.

In situ (in the car) the EJ-22's are amazing. That is where and how they were designed to be used.

Take the engine out of the car, attach a redrive and non soob components, run it in a high vibration environment at aircraft RPM and load factors and we have a whole new game.

EJ-25's have problems even in the cars. The early years esp. had head gasket issues.

Issue.........................................................Soob.......Aircraft Engine

Purpose design............................................n............y
Manufacturer support...................................n............y
Designed to turn prop...................................n...........y
Manufactuer service flaw tracking (aircraft).....n............y
Mechanic feedback to mfgr on flaws...............n............y
AD or Service Builitin system........................n.............y
Mfg designed and built redive (if needed)........n............y
Designed for high RPM use............................n ............y
Mfg standardized mounting and hardware........n............y
Mfg cooling system used................................n............y
Mfg electrical and charging system used...........?............y
Able to function after charging or elect fail.......n(few).....y
Fully redundant ignition system......................n(vfew)...y
Large numbers of standardized installations......n...........y
Designed for high power:weight......................n...........y
"over engineered" for application.....................n...........y
Known documented usage and mech history.....n(if new).. common
Adapted from FI to carb..................................common..n
Stock manafold not used................................common...n
Failures likey to be catastrophic ("out")............common...n
Cooling problems common..............................y.............n
Crank failures common...................................y (induced) n
Redive application raises thrust line..................common....n (not sig)
High investment return on resale value..............n............y


Again I am not trying to throw a wet blanket on all of the soob lovers.

I love soobs myself and it is indeed a testment to their design that they can perform as well as they do when adapted to aircraft use.

A dangerous issue as I see it is when anecdotal evidence (like seen here in this thread) is used to try to convice the unexperienced new comers that an auto-conversion is as reliable as a purpose built aircraft engine. That is simply not true.

I LOVE my soob gyros but I don't have the confidence in them that I do in an aircraft engine.

All aircraft engines can fail but how often and how catastrophic the failure is dramaticly changes between engines and applications.

I personally know several people that bought used gyros or kits that could have afforded aircraft engine powered machines if they had exercised patience. They then became frustrated by the recurrent problems and tinkering and left our sport for good.

We don't have much choice for affordable engines to power 2 place gyros, but single place machines we can get affordable 2-stroke used Rotax engines for.

Please read: http://en.wikipedia.org/wiki/Anecdotal_evidence

If you have the money or can get an aircraft engine if you get a loan or wait another year to two, go for the aircraft engine.

If the only possible way you can afford to fly is to use an auto-conversion then welcome to the club. However, don't convince yourself, your passingers or others new to the sport that the engine has the same qualities as a purpose built aircraft engine. You really do get what you pay for.

.
 
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