Subaru Engine

Discussion in 'Home Builders and Sport Pilots' started by MHarrow, Jan 30, 2019.

  1. painless

    painless Pre-takeoff checklist

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    Jeff Orear
    If you are not comfortable with the engine you are potentially flying behind, where is the fun in that? Make an offer on the airframe factoring in swapping out the Subie for a Rotax. Recoup what you can by selling the Subie. Walk away if no sale.
     
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  2. zaitcev

    zaitcev En-Route

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    I know a guy who has a Subaru with 315,000 miles (well, more now). It's his daily driver, and he works a factory floor. Although, he was "thinking about" replacing it for the last 3 years at least.
     
  3. weilke

    weilke Touchdown! Greaser!

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    You just got to do it right. VW based direct-drive engines have been in use in touring motorgliders in europe since the 1950s. Now they don't pull an engine out of a beetle, companies like Limbach and Sauer start with industrial engine kits from VW and build the engine with lots of aircraft specific internals. Most of them are in the range between 75 and 100hp (DIN) and have been very reliable.
     
  4. Doc37

    Doc37 Filing Flight Plan

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    There is nothing wrong with auto engines in airplanes other than trying to make them conform to the stupidity inherent to modern thinking influenced by FAA insanity. The reason (Forgotten) for a redundant starter system is because of the crappy electrics in the 30's. Todays modern engines electrical systems are superior to current aviation engines... The Subaru engine was designed to be an airplane engine and the EA81 is only less than the EA82' Why reduction? This is because the engine is overly powerful for GA needs.Use direct drive and put a stop on the throttle to where it cannot exceed 3,000 rpm. Doing this will eliminate the annual and change it to the bicentennial. Think about it, if pilots were smart they never would have permitted the bureaucrats in FAA to ruin such an inherent right we call aviation. For proof let me ask you :"what difference does it make if a sport pilot buys a plane that is rated to 1450 LBs as opposed to their stupid 1260 Lb infringement? The pilots can physically handle and fly both. What it does do is hurt the industry and kill the sales of a lot of Ercoupes, Piper Pa 28's etc. Take back aviation, fly safe and relegate the FAA to commercial aviation only unless they infringe on GA. That said quit trying to destroy auto engines by converting them to idiotic thinking. Use their electrical system as is , use direct drive. eliminate all regulations not productive to the enjoyment of flying and prepare to smile a lot. Once you overcome dinosaur thinking you will discover the Auto engine will last longer than you will and maybe he next several pilots of it as well will no crashes and a hell of a lot cheaper than mind block thinking.(And never forget HP does not drive props torque does)
     
  5. Kenny Phillips

    Kenny Phillips En-Route

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    Horsepower drives the prop at the proper speed with the proper pitch; power (as the term is used for recip airplane engines) is the product of torque and RPM. I can get a million foot-pounds of torque out of a lawnmower engine with the proper gearing. Hook it up to a prop and you get ... not much airflow. Auto engines may have "too much power", but that's rarely used. Airplane engines run at a greater percentage of their maximum power for most of their lives than anything outside of auto racing.
     
  6. Dana

    Dana Cleared for Takeoff

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    I'm not real familiar with Subaru or Corvair conversions, but the VW conversions have a pretty good track record. Other than redrives, some of which are good and some are not, where you run into trouble with auto conversions is when you try to get more continuous power out of them than the cooling system can handle. VW engines are limited in the max continuous HP they can put out, but they're cheap.

    I flew behind a half VW for a few years. Limited power, cheap parts, easy to work on... and the biggest trouble I had with it was its Slick aircraft magneto.
     
  7. PaulS

    PaulS Final Approach

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    Yup, horsepower is important.
     
  8. Doc37

    Doc37 Filing Flight Plan

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    Horsepower has nothing to do with driving the prop., because Horse Power is hypothetical and speculation, i.e. it does not exist in the real world.Torque is the only thing driving a prop. So called airplane engines have to use two spark plugs for every cylinder for reasons GA has forgotten all about. The redundant requirements have nothing to do with fact other than in the 20's and 30's we did not have the advanced electronics we do today.If you want to have an adjustment to your thinking read all about B.H. Pietenpol and his use of the Model A car engine for flight. It was only a 40HP rated engine yet it could fly two 200 Lb men with ease because of torque. This was an inferior engine by any standard yet it is still flying after 80 years. What were you saying about dependable?
     
  9. Doc37

    Doc37 Filing Flight Plan

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  10. Kenny Phillips

    Kenny Phillips En-Route

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    Ignorance is curable.
     
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  11. Doc37

    Doc37 Filing Flight Plan

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    AS FOR AIRFLOW FROM A PROP THAT IS DECIDED BY THE RPM IT IS SPINNING. AT AROUND 3000 RPM IT IS SUPER SONIC AND USELESS. Most modern auto engines can turn 7,000 rpm but not all day, however 3,000 rpm and less is nothing for them and they have ample torque to sustain that. And they do not require a redundant spark plugs
     
  12. Doc37

    Doc37 Filing Flight Plan

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    Stupidity is terminal!
     
  13. PaulS

    PaulS Final Approach

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    I can apply 2,000 lb ft of torque to a 2 inch bolt by standing on a 10 foot cheater bar. But no work gets done. Torque is a measurement of force, horsepower is a measurement of work done. Moving an airplane requires work to be done. Horsepower spins the propeller and keeps it spinning. Torque is the force applied to the propeller, but again, full torque, in theory, could be applied to a stationary propeller and no work be done.
     
  14. wanttaja

    wanttaja En-Route

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    Being in existence for 80 years is not the same as being reliable, nor does one example prove anything.

    If you look at homebuilt aircraft accidents from 1998 through 2016, about 25% of the fixed-wing aircraft accidents were due to problems with the engine. For fixed-wing homebuilts powered by traditional engines, 18% of the accidents were due to power issues. For auto-engine conversions, it's 43%.

    Certainly individuals can and have produced reliable auto-engine conversions. Statistics indicate the average homebuilder has difficulty with the process.

    Ron Wanttaja
     
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  15. Kenny Phillips

    Kenny Phillips En-Route

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    But you'll never convince some people.
     
  16. Flybuddy

    Flybuddy Pre-takeoff checklist

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    If anyone is interested in an aviation Subaru set up my next door neighbor removed one (4cyl) from his RV6 and replaced with an O360 Lycoming. He flew a lot and just wanted more power and got a good deal on the Lycoming. He had put about 500 hours on the Suby. It comes with an MT prop and can be had cheap.
     
  17. UrfinJus

    UrfinJus Filing Flight Plan

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    If anybody experienced with Honda conversion? Also promoted like Vicing 130hp. Please comment this engine.
     
  18. James331

    James331 Touchdown! Greaser!

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    The only thing I am not a fan of is the non direct drive you find on many auto conversions, but that also applies to aviation engines.

    I’ve driven and wrenched on Subaru’s and I really like their engineering, at least in land based toys.
     
  19. Shuswap BC

    Shuswap BC Pre-takeoff checklist

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    I had a Subaru WRX for 4 years, not one mechanical problem with it, just regular maintenance. That engine seemed to be bulletproof.
     
  20. weilke

    weilke Touchdown! Greaser!

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    You also didn't drive it at full throttle 90% of the time.
     
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  21. tspear

    tspear Pattern Altitude PoA Supporter

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    You would be surprised how hard I ran mine. Three years, 120K miles, very few cruising miles. Generally running traffic (DC area), mountains roads (western MD), often with the engine between 4K rpm and 6K to get the best power.

    Tim
     
  22. weilke

    weilke Touchdown! Greaser!

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    For every trip up Polish mountain, there is a trip back down. Even at 70 or 80mph, the car engine only puts out less than 50% of its rated power.
     
  23. tspear

    tspear Pattern Altitude PoA Supporter

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    Ah Polish mountain. Fun roads through there,
    Anyway, downshift, compression braking actually runs the engine pretty hard. Saves brakes.

    Tim
     
  24. IK04

    IK04 Pattern Altitude

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    Coming from the experimental Gyroplane world, all the auto conversions have been just as reliable and powerful as certified or experimental modified aircraft engines. The Two-cycle engines are more prone to failure for all the usual reasons.

    The modern Honda or Mitsubishi conversions like the Viking, with dual ignition and redundant ignition have excellent safety and durability records and are only as good as the knucklehead who operates them...

    Personally, I would prefer a Corvair conversion, built by me from parts from flycorvair.com.
     
  25. Capt. Geoffrey Thorpe

    Capt. Geoffrey Thorpe Touchdown! Greaser!

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    Look at the third post in this thread. https://www.pilotsofamerica.com/community/threads/subaru-engine.116582/#post-2672096
    Auto conversions are not failing because the engines are wearing out. Cooling (which can be an issue when running continuously at 75-100% for hours on end. No matter how good your radiator is, if the piston crown or the head overheats, u b skrewt), reduction units, ignition, "undetermined" (engine did not blow up).

    Running for a bazzilion hours in your butt hauler means nothing. I just rolled over a buck and a half with my Focus in spite of the fact that I suck at getting the oil changed and use it to pull a trailer (POH sez "There is no trailer tow package for this vehicle").

    I also worked on the Ford 2.3L turbocharged engine back in the olden days. They were fine in the US. Tended to melt the top edge of the piston when the engineers got them on the autobahn in Germany. Different duty cycle.
     
  26. steingar

    steingar Taxi to Parking

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    The fact that the OP has to ask a group of complete strangers on the internet if the engine is safe answers the question right there.
     
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  27. wanttaja

    wanttaja En-Route

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    In the rotary winged world, auto conversions have had proportionately fewer reported accidents. This table shows the percentage of total accidents due to loss of engine power for both fixed wing and rotary winged homebuilts. Auto engines, indeed, come out better.
    _________________________|_Fixed Wing_|_Rotary Wing_|
    ___Traditional Engines___|____17.8%___|____16.7%____|
    _Aftermarket Traditional_|____17.9%___|____33.3%____|
    _____Foreign Designs_____|____28.0%___|______-______|
    _______Auto Engines______|____43.3%___|____11.5%____|
    __Non-Cert Four Strokes__|____17.8%___|____28.7%____|
    _______Two-Strokes_______|____35.7%___|____29.4%____|


    I'm suspecting the flight mode of gyros tends to minimize the effect of engine failures. The aircraft is autorotating anyway and gyros tend to be able to land short, so an engine failure may be less likely to result in a reportable accidents.

    Ron Wanttaja

     
  28. Rogue_Ryder

    Rogue_Ryder Filing Flight Plan

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    There's a lot of info/debate out there on the Vikings
    http://www.vansairforce.com/community/showthread.php?t=27258

    I love the idea of "Modern" engines, but I think if I were going to put a "Modern" Engine in a plane that I'm going to be flying in it would be a Rotax, Jabiru, UL, etc. not a car engine and more than likely if I built an airframe that could accept it; I'd run a non-certified or a lost logs/tags Continental or Lycoming. "But the Car engine makes more power and 1/2 the cost" yeah that's a good argument for any automotive engine; but what about 10 years down the line? Rotax will probably still be producing new 912s while Honda will have long since abandoned their engine and may not even offer any OE parts (I sure as heck wouldn't want to be maintaining the powerplant of my aircraft with Chinese parts from Autozone). I'm not sure if Rotax 912s can run on avGas but let's say you land at a field that doesnt' have Mogas, you're forced with putting in 100LL; that is NOT good for single plug car engines. I've seen lead fouled plugs on real aircraft engines, but because of the dual ignition system no failure or power loss; get a lead fouled plug on that tiny Honda Spark plug that fouled plug might mean you're crashing.

    Some good discussion on the Subaru's here:
    https://backcountrypilot.org/forum/subaru-e81-engine-reliability-12702

    An EA81 Subaru makes similar peak power to an O-200; and you can get a timed out core (well cared for O-200s can go well beyond the 1800 TBO) or one with lost logs or tags for a reasonable price. Since you're installing it on an experimental you can overhaul it yourself and put in higher compression pistons and a different cam and get more power out of it! There's so much information and knowledge out there on the O-200 it's not even funny.
     
  29. Capt. Geoffrey Thorpe

    Capt. Geoffrey Thorpe Touchdown! Greaser!

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    You can, just change the oil and inspect the gear box more often if you run on 100LL most of the time.
     
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  30. topgun260

    topgun260 Pre-takeoff checklist

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    Why has it been sitting for 10 years?

    Doing a Google search for Subaru conversions for aircraft will get you some great reading. Lots of history, not all good.