MT prop on S-2A, is it worth it?

Discussion in 'Firewall Forward & Fuel System' started by Flying Ant, Jun 11, 2013.

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  1. Jun 11, 2013 #1

    Flying Ant

    Flying Ant

    Flying Ant

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    One of my friends is restoring and S-2A, 1972 Factory build, I guess that makes it one of the earliest ones. Anyhow we were discussing the merits of the 3 blade MT conversion, what's the thoughts of those who have tried it?

    Worth the money? Different to fly? Better? Worse? Same?
     
  2. Jun 11, 2013 #2

    PittsDriver68

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    Another local pilot did that conversion. My observation was that it looked really cool but I had no problem posting a higher score at contests. Some folks on the Acro Exploder have posted the results of the best comparison testing that they could do and near as I could tell the available MT performed somewhat better than the aluminum Hartzell, but maybe not enough to justify the cost for that reason, and maybe not enough to give you a competitive advantage. The big win is the loading on the crankshaft. The guy who bought one wanted to try some tumbles in his S-2A and you should not do that with a Hartzell prop if you want to avoid problems.

    MT needs to come up with blades that provide performance closer to what the Hartzell Claw does. That would be a winner.

    Best of luck,

    Wes
    N78PS
     
  3. Jun 11, 2013 #3

    an8pilot

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    MT compared to going with composite fixed pitch 3 blade prop?

    Or, should that not even be brought into the conversation?














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    Last edited: Jun 11, 2013
  4. Jun 11, 2013 #4

    smutny

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    When I saw the new 2-blade MT on the Xtreme Decathlon, I wondered if that was the goal. That might make a good S-2A, S-1T and Eagle prop.

    Have been meaning to do a little research on it.
     
  5. Jun 11, 2013 #5

    smizo

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    I flew the extreme decathlon on Sunday, that prop pulls like mad! It also has a huge ammount of drag when you pull off the throttle. That prop and the 390 are a great combo!

    I heard the blades are the same as on the extra 330 but there's just 2 of them on the 390
     
  6. Jun 11, 2013 #6

    PittsDriver68

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    The challenge is that MT has not announced that they are putting the new blades on the 3 blade prop STC'ed for the S-2A. And the two blade used on the Extreme D is not STC'ed for the S-2A. One of the posters here talked to MT about this. Perhaps someone else would like to speak to MT?

    Best of luck,

    Wes
     
  7. Jun 11, 2013 #7

    S2e

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    I have an S2E. I would like to replace my Hartzell. From what I am reading, it seems Whirlwind might be a better choice for me than the 3-bladed MT.

    But, if the 2-bladed MT pulls like the poster who flew behind it in a Decathlon wrote, I wonder if that is a good option for me and my S2E?

    I guess I'll talk to them at Oshkosh about it. (If my wife lets me go this year.)

    (I really like the idea of being able to use my existing governor with an MT product. I understand the new governors are better than my old Hartzell governor. But, I have a rear mounted governor. I'm really not looking forward to replacing it and figuring out how reroute the prop governor cable. My patience with building ended 28 years ago when we finished building the Pitts.)
     
  8. Jun 11, 2013 #8

    Redfoot

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    I was thinking the same thing. "how would this compare to the Hartzell 2 blade claw"... With the construction of the MT being mostly wood compared to the Hartzells' carbon kevlar whatever maybe that reported bad harmonics would not be a factor.....
     
  9. Jun 11, 2013 #9

    smizo

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    As far as I know the XD MT prop is only being put on the 210 hp 390 so that may be a factor......
     
  10. Jun 11, 2013 #10

    smutny

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    Well then, it's time for the 390 to be STC'd on the S-2A and S-1T.

    Who's gonna get right on that?

    Bueller...? Bueller...?
     
  11. Jun 11, 2013 #11

    jerr888

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    Hi all:
    Is the 3 blade MT a little heavier (1#) than the 2 blade hartzell?
    Is the 2 blade whirlwind about 15# lighter?
    Seems like less weight on the flange is the best way to reduce stress, even if the prop disc is a little larger in diameter?
    Jerry
     
  12. Jun 11, 2013 #12

    PittsDriver68

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    Those weight estimates are correct. But even with the 3 blade the big win is where the weight is distributed. The MT weight is in the hub more than the blades so the front of the crankshaft is not flexing as much. The gyroscope has less inertia to overcome when you do snaps or whatever.

    They guys who fly MT's tell me that it changes the feel of the airplane when doing hammers and snaps.

    The 2 blade MT or Whirl Wind sounds like a great idea for an Experimental.

    Come out to the Northeast contests and score some points with one.

    Best of luck,

    Wes
     
  13. Jun 11, 2013 #13

    smizo

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    Good - bad, or just different?
     
  14. Jun 12, 2013 #14

    PittsDriver68

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    I think that its just something you get used to. I think that I recall being told that the airplane feels looser as you are not coaxing as much of a gyroscope around. With the Hartzell, when you pitch quickly you need more rudder as the gyroscope translates each input 90 degrees according to the right hand screw rule that you learned in physics class.

    Getting back to basics though, World Champion Leo Loudenslager once famously said that if you have $100K and you want to win contests, spend $50K on an airplane and the rest on gas and coaching. I keep telling myself that as I drool over cool accessories for my airplane. My current experience is that if I do my part, the airplane, with its Hartzell propeller, gets me the points to take home a trophy. I just have to consistently do my part.....

    Best of luck,

    Wes
     
  15. Jun 12, 2013 #15

    Optima200

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    I used both the hartzell metalic prop and now the 2 blade MT propeller on my " modified s2a"
    As wes says the feeling in Hamerhead is different (less to no rigth ailerons) and snap are different . All the aircraft feel lighter.
    In cruise it is nearly the same but in climb the Mt is a little bite better.
    The main advantage is gyroscopic force on the flange .

    A freind of me use the 3 blades and regrets the 2 blades , he saw a small decreasing in climb and cruise but with less noise:cool:
     
  16. Jun 12, 2013 #16

    plschulten

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    I went from the 2 blade metal prop to 3 blade MT on my Eagle. It totally changes the way the plane flies. About 5K less cruise speed but better climb, much more "pull" at low speeds vs high, LOTS less gyroscopics, LOTS more drag with the power back. I really had to relearn how to fly the airplane. For a given pressure/movement on the stick in pitch, the plane will pitch much quicker with the MT - its like someone took a big dampener off the front of the plane, or, put another way, it greatly lightened pitch forces. Roughly 1/3 of the rudder is needed on a hard pull to vertical. It takes some getting used to but is all good. Steve Wolf puts it best - the plane is much "happier" with the MT. ;)
     
  17. Jun 12, 2013 #17

    wminear

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    I have whirlwind blades in a McCauley hub with a rear governor on an io-360. My 360 came off a Mooney, so it has the lightened crankshaft so I'm concerned with the gyros on my hub. I don't believe the whirlwind are STC'd yet, but the blades are much more reasonable priced compared to MT blades.
     
  18. Jun 13, 2013 #18

    plschulten

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    I seem to recall reading somewhere the MT prop vs the metal two blade was 67% less gyroscopic forces - don't know but it feels like it from where I'm sitting.
     
  19. Jun 13, 2013 #19

    an8pilot

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    Wow that's an interesting thought. Whirlwind blades on a McCauley hub.

    I didn't know that was possible.

    So do you just ask Whirlwind to fit blades to your hub?

    How bout a 3 blade McCauley or Hartzell hub?





    .
     
  20. Jun 13, 2013 #20

    PittsDriver68

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    I believe that Whirlwind and maybe MT did not originally make their own hubs. They do now. McCauley apparently will sell their hubs to other manufacturers. Never heard of Hartzell doing that. So there appears to be some ability to mix and match components. That said, this is NOT something to be done casually. A propeller failure often results in very substantial damage to the airplane. There is a lot of ground testing done before a propeller is first hung on an airplane. Some manufacturers sell to the airboat industry first to build up reliability and durability, before moving to aircraft.

    Best of luck,

    Wes
     

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