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Thread: Engine Help??

  1. #11
    Matt Gonitzke's Avatar
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    Quote Originally Posted by martion007 View Post
    I figure it like this, (My opinion only) An automotive engine is alot more reliable than any certifyed aircraft engine because millions more have been spent on designing them.
    There is no correlation between the amount of money spent on something and how good of a product it is. Good products are developed with little money, and bad products are developed with lots of money, and yes, sometimes the reverse is true. An auto engine is designed to live a long time by being run for a long period of time at a small fraction of its rated horsepower; and aircraft engine is designed to live a long time by being run near its rated horsepower for a long period of time. Statistically it seems that auto engines installed in aircraft are less reliable than aircraft engines, but there are also a lot of other variables, too.

  2. #12
    Aaron Novak's Avatar
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    Quote Originally Posted by Matt Gonitzke View Post
    There is no correlation between the amount of money spent on something and how good of a product it is. Good products are developed with little money, and bad products are developed with lots of money, and yes, sometimes the reverse is true. An auto engine is designed to live a long time by being run for a long period of time at a small fraction of its rated horsepower; and aircraft engine is designed to live a long time by being run near its rated horsepower for a long period of time. Statistically it seems that auto engines installed in aircraft are less reliable than aircraft engines, but there are also a lot of other variables, too.
    Matt,
    You are 100% correct. Automotive engines have far different requirements than aviation engines. From a base engine perspective they are designed to run at about 15% power output for extended periods. Some are better than others, but the primary goal of the auto engine maker is to design an engine that passes emissions, lasts long enough to get out of warranty, and to be as CHEAP as possible. And no im not talking about "harmonic balance", whatever that is. ALL inline 4 engines with a flat plane crank have a second order vibration, hence the balancer that spins 2x crank speed. Low speed car engines can get away with it if the engine is heavy enough. But a light engine mass can be a real problem. Maybe someone has one of those "viking" engines with 2000 hours on it? It would be interesting to see how long it would really last.

  3. #13

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    Quote Originally Posted by martion007 View Post
    I don't think You would have that with the Viking engine or they wouldn't be selling them. If You check out their website You can tell they have extensive experience in aircraft engines.
    Eggenfellner does have an extensive engine background with Subaru engines. Unfortunately, customers give/gave mixed reviews (at best) on those engines. A google search of "Eggenfellner engine problems" will deliver a lot of information.

    Will the Viking engine be different? Who knows. Personally, before I invested my $$ and time, I'd wait until his initial Viking customers put enough hours on their engines to give some indication of whether the engines are a good Rotax replacement, or whether they are a disappointment like the Subarus were as Lycoming replacements.

  4. #14
    Max Torque's Avatar
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    Corvair!

    Buid it as specified by William Wynne - www.flycorvair.com - (or have William build one for you) and don't look back.
    "You have to be alive to spend it..."

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