O-100-- interesting new engine

Discussion in 'Firewall Forward / Props / Fuel system' started by Dana, Jul 19, 2012.

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  1. Jun 25, 2019 #941

    rv6ejguy

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    As I've mentioned previously, multiple times in this thread, I like what Peter is doing with this and how he wants it to be as good as possible before market release. He's done an awesome job so far.

    My only point here is not to put out performance numbers on engines or aircraft (think Raptor or Synergy) or any other new design which have not been validated by actual testing. It serves little useful purpose and may come back to haunt you later. This applies to me , you, Pete, anybody, no matter their background- doesn't matter.

    People hopefully know enough that this half displacement engine, based on O-200 jugs, is going to only put out about half of what the big brother does- whatever that is, but it almost for sure isn't 58hp at 2900 rpm.

    And yes, power figures matter big time to safe ROC on aircraft. If someone is on the marginal side of power requirements and an engine falls short by 15-20%, that won't end up well and they won't be happy.
     
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  2. Jun 25, 2019 #942

    Hot Wings

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    But we shouldn't be and that is Pete's fault. He never should have mentioned performance numbers until he had hard numbers in his hands. Just knowing that the hp will be half-ish of the full O-200 would have been good enough.

    In the real world it won't make much difference if it makes 38hp or 50hp. The O-100 has no real competition in it's niche and looks like it will supply adequate power for it's intended market segment, based on it's limited flight testing. For me, that is good enough.
     
  3. Jun 25, 2019 #943

    blane.c

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    DP-1? lol.
     
  4. Jun 25, 2019 #944

    blane.c

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    I have balanced engines for pay. I agree. But caveat, if the aforementioned engines with numerical cylinder superiority, have inferior balance mechanism or technique to engines with lesser cylinders the engines with lesser cylinders can gain an advantage.

    Having flown airplanes before and after the engine's were balanced properly, I can say from my experience "stock aircraft engines are not balanced very well at all". Crappy balancing I say from a stock aviation engine. Crappy.

    The O-100 video I have seen shows a properly balanced engine.
     
  5. Jun 25, 2019 #945

    BBerson

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    A two cylinder even with perfect rotational and reciprocating balance (not possible) still has stronger torque pulses then a four cylinder. Can't really say much from a video. My v-twin looks perfectly still but still has stronger vibration compared with a four cylinder.
     
  6. Jun 26, 2019 #946

    Topaz

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    I absolutely agree with you on all points, but imagine how the Internet would be talking now if he hadn't mentioned any numbers at all. The dog-pile would be quite spectacular.

    "Why won't he say any numbers? It must be crap!"

    "He's not releasing numbers, even a guess! He must be having problems!"

    ad nauseum

    There's no way to win, excepting not letting knowledge of the project get out at all until it's complete and dyno testing has already been done. The Internet's going to pummel him either way.
     
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  7. Jun 26, 2019 #947

    Toobuilder

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    I'm not questioning the integrity or passion of Pete, but Ross' reasoning is sound:. The accessory losses of an O-300, O200 or O100 are going to be about the same. That geartrain loss is going to be the same regardless of the number of cylinders powering it. And the number of cylinders driving the total output is a very simple math excersize. All the "positive energy" on the internet is not going to change the physics - the output of the O100 is going to be directly linked to the output of the O200 and O300... No way around that.
     
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  8. Jun 26, 2019 #948

    Topaz

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    You're making some assumptions that simply aren't true. I'm not at liberty to go into details, because I don't have Pete's permission to do so but, again, the O-100 at this point is no longer "half of an O-200", but more a custom airplane engine that happens to use some Continental parts. I absolutely and completely respect Ross' experience and opinion, but you guys aren't working with all the facts. Unlike some others here, I'm not saying Pete's guesses at output (and he would absolutely characterize them as such and has, to me) are accurate or that they're not. I am saying that the CrackerJack, with the direct-drive "O-100" bolted on the front and a full-sized person in the cockpit, behaved in a very spritely manner, more so than I would expect a ~40hp engine to give it. I've seen several direct-drive VW conversion planes of roughly the same size as the CrackerJack operate, so I do have some point of reference. And that's my eyewitness report, obtained first hand. Neither you nor Ross can say as much.

    And for the record, my opinion isn't "positive energy", and it saddens me to have you suggest otherwise. I've got no skin in Pete's game. I've had the good fortune to see behind the scenes in his efforts on a couple of occasions because I happened to be at the right place at the right time to get the views. I understand the physics and would agree with the opinions proffered if all the assumptions were correct but, again, you're working from incomplete information and why don't we just wait and see before we decide what's wrong with everything about this engine, shall we?
     
    Last edited: Jun 26, 2019
  9. Jun 26, 2019 #949

    Toobuilder

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    The "positive energy" comment was not meant to be disparaging to anyone, merely an engineers view of reality. There may be some real genious in the design, but the cylinders are 95% of the output of an engine and if those are stock Continental parts, there's not much room for improvement. If there IS, then Pete has a lucrative career tuning F-1 engines ahead of him. This is a wet flow, carbureted engine with magneto ignition... The easy boost in power/efficiency hasn't even been touched. If he can significantly boost the specific output of a stock Continental cylinder architecture, I'll be calling him the next day to pick his brain, believe me.

    Having said that, I'll withold further speculation until dyno values are validated. But as someone who LIVES to eke out a few percent more efficiency from an aircraft engine, I remain highly sceptical of the percentages claimed here. Good engine, good product, no doubt - but the specific power claims are really a bit outside the "reasonable".
     
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  10. Jun 26, 2019 #950

    rv6ejguy

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    Further to this, the O-200 I ran extensively on my test stand was not turning any mags or alternator, it was running a dead loss system off a big battery. This casts even more doubt on the O-200's stock output figure when turning these accessories. Bottom line, my O-200 with optimized timing and AFRs, was unable to turn the identical prop any more rpm than an 80hp Rotax. I'll also mention that our O-200 has more throttle body throat area than the stock carb and would pull nearly ambient MAP at WOT which should have freed up even a couple more hp over stock if there was any more to be freed up in that area.
     
    Last edited: Jun 26, 2019
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  11. Jun 26, 2019 #951

    rv6ejguy

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    Here are photos of the 2 engines on my test stand.

    rotax108.jpg

    contirun5.jpg

    rotax109.jpg

    Eventually we ran with a calibrated test club to verify power more accurately.
     
  12. Jun 26, 2019 #952

    BBerson

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    That's interesting but could be unfare to Continental. The Rotax looks new. I assume from the looks the O-200 was perhaps 40 years old with unknown internal condition.
     
  13. Jun 26, 2019 #953

    12notes

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    What did those two engines dyno at? Look, you might be right, but without those you're requiring Pete to have dyno numbers before making a power claim while you're making power claims without having dyno numbers.

    No offense, but I think a knowledgeable and experienced guy who has access to the engine in question has a more valid opinion over a guy, also experienced and knowledgeable, that only did some analogous testing on different engines without measurable data.
     
  14. Jun 26, 2019 #954

    rv6ejguy

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    These are not on a dyno however I think we can agree that a Rotax 912UL doesn't put out 100hp. When test running the 912 with the calibrated 4 blade club you see, max corrected power came in at 81hp with the carbs, a little over the rated rpm. The O-200 was not run with the club as it was borrowed from a Rotax dealer years ago but we did run both with the same prop that I own here.

    You folks can believe what you want. I've been doing this stuff for 40 years and built my own dyno 30 years ago and have logged thousands of pulls on several different dynos on about 180 different engines, so I'm somewhat familiar with this topic. William Wynne also dynoed an O-200 and came up with only 80-81 corrected hp: http://www.flycorvair.com/thrust.html. This closely matches my observations.

    So while I've presented some compelling real world test numbers here to support my view, everyone else is just speculating. Show me a dyno or club run on a stock O-200 producing 100 hp at 2750rpm and I'll take notice.

    To think that an O-100 with a bit more CR will produce 58hp at 2900 is not supported by any facts that I can see.
     
    Last edited: Jun 26, 2019
  15. Jun 26, 2019 #955

    BBerson

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    WW could be a biased competitor in the same market. There must be some other unbiased data on the Continental engine other than Continental. How do they certify the data for a Type certificate?
     
  16. Jun 26, 2019 #956

    BJC

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    I don’t know how they certify the data, but they do claim 100 HP.

    http://150cessna.tripod.com/e252tcds.pdf


    BJC
     
  17. Jun 26, 2019 #957

    AJLiberatore

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  18. Jun 26, 2019 #958

    Victor Bravo

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    OK, then let's ALL stop talking about horsepower until the Dyno is done. That includes the people saying it will and will not make X horsepower. Deal?
     
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  19. Jun 26, 2019 #959

    blane.c

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    I like the soft hue of the aluminum alloy cases.
     
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  20. Jun 27, 2019 #960

    dragon2knight

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