Static Thrust from VW engines

Discussion in 'Volkswagen' started by Rienk, Sep 10, 2014.

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  1. Sep 10, 2014 #1

    Rienk

    Rienk

    Rienk

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    Does anyone have real-world, actual test data, for static thrust measurements from any sort of VW aero engines? I hear a lot of banter about what engines can do, but no one seems to have done a simple static thrust test of their engine/prop combination.I would love to get some real measurements of rpm/prop settings to get an idea of what the VW's can actually do.

    BTW, the only info I've found so far is from Great Plains, in reference to the redrive that the provide from VE.

    The Reduction Drive Engines have really opened up the range of aircraft that can use VW power. Direct drive VW's are limited to a 62" diameter prop because of tip speed. They will produce about 200 to 250 lbs. of thrust, depending upon prop manufacturer. The reduction drive engines can turn prop diameters from 72" with a 1.6:1 ratio and up to a 84" prop with a 2.0:1 ratio. Static thrust with a 72" prop is about 350 lbs. The 2:1 ratio with a 84" prop will deliver about 450 lbs. of thrust.
     
  2. Sep 10, 2014 #2

    Norman

    Norman

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    Wouldn't it be better to measure engine power with a club dynamometer than to measure the thrust of a stalled prop?
     
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  3. Sep 10, 2014 #3

    Dana

    Dana

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    Static thrust doesn't really tell you anything useful about how the engine is going to perform on the plane. A prop that's correctly optimized for thrust at a faster airspeed will have less static thrust than one optimized for a lower airspeed.

    Dana

    "I don't practice what I preach because I'm not the kind of person I'm preaching to."
     
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  4. Sep 10, 2014 #4

    Rienk

    Rienk

    Rienk

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    I do understand that thrust at (any) speed is different than static, but it's a simple measurement that I can figure out now.
    We have a simple water dynamometer, but it's such a pain to set up and keep calibrated. So right now, while we're tuning our intake and exhaust, I'm being lazy and using static thrust for comparisons. Fine tuning and power verification will be with the dyno or torque mount.

    Nonetheless, I am an interested in what various VW engines put out as well - again, for some basic comparisons.
     
  5. Dec 26, 2014 #5

    PixiePilot

    PixiePilot

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    A lot of the previous inputs are helpful, but...my experience with a 1.7 L 4 cyl
    vw might be userfull in your quest for the right engine/prop combination. The engine has about 8:1 heads and i run 93 octane or AV gas. The first homebuilt it powered was a Sonerai 1 using a Hegy prop, as I recall 48X44pitch. After a few botched landings I realized my Cessna 150 training did me no service trying to land a pocket rocket...OK broken landing gerar and axle. Next I tried this combination (patched and balanced prop) on my newly finished Pober Pixie. Take offs were white nuckle affairs and m..ax static rpm was about 2800, well below the power curve I needed...but it did cruise at 2200RPM. I tried a new prop, as I recall 52 X something which yieled 2850 RPM and 185 lbs of static thrust. Still not within the 53 HP he little 4 banger should produce. Now I have a 56X28 prop by Sterba which runs 3300 Static and 225 lbs thrust..joy to fly...think about 4 lbs of thrust per one HP here.
    Regards, Pix Pilot
     
  6. Dec 26, 2014 #6

    Turd Ferguson

    Turd Ferguson

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    Here ya go, this guy got 205#.

    https://www.youtube.com/watch?v=2S22hONa3o8
     
  7. Dec 26, 2014 #7

    Pops

    Pops

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  8. Dec 27, 2014 #8

    Turd Ferguson

    Turd Ferguson

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    Yes, it is a type IV, intended to provide a data point. The original poster said he was "interested in what various VW engines put out"
     
  9. Dec 27, 2014 #9

    Pops

    Pops

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    Sorry, I was thinking CC's no types. Not very many Type 4's used in aircraft. For the weight, HP and cost, just better to buy a small continental core and overhaul or build from parts.

    Dan
     

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