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Polishing intake manifolds

in General Tech Discussion 7 years ago

  • Re: Polishing intake manifolds

    by » 7 years ago

    Don't have any test instruments at all. But I do feel it with my seat. I did get some compliments from local pilots who were watching me taxiing and taking off. They think engine sound very good.

    Engine runs very stable at 1600 RPM. I can go lower but I was told it's not good for the gearbox.

    I know it is not very scientific answer. But if it is for sure good enough for me. So it was for many another guys I talk to. And for another company in Europe who started to make replacement kit with one inch balancing tube.
      
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  • Re: Polishing intake manifolds

    by » 7 years ago

    Most well designed 4-cycle engines include some tuning of the intake manifolds to take advantage of the pulsing air flow due to the opening and closing of cylinder intake valves. This allows the natural pulsing to help "supercharge" the intake air/fuel and pack more into the cylinders. I don't know how much of this effect is designed into the Rotax 912, but it seems to me that any crossover tube, especially a large one, would have a negative effect on this feature. I haven't heard anyone bring this up in this discussion, but I think it is food for thought and would support Roger's premise that without instrumented testing we don't know all the side effects. The large balance tube may mask out of sync carbs, but may also be somewhat reducing overall power and efficiency.
    Thank you said by: Rob Seaton
      
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  • Re: Polishing intake manifolds

    by » 7 years ago

    Eugene, checkout the vibration monitors for the iPhone in the App store. For about $5 some are free you can get an app that monitors and records vibration on the X,Y and Z axis.
    Thank you said by: Eugene Klimenko
      
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  • Re: Polishing intake manifolds

    by » 6 years ago

           Finally managed to stop and talk to Rotax guys at OSH. They didn't have any problems with my 1" balancing tube. They do understand what it does and they did tell me that 10 years ago some company in Europe did some testing and found it to be beneficial. And "if it is working for you, and you feel the difference, then keep it! No problems at all!"

         Flying in and trying to keep up with everybody, my oil temp got to 220°F. But they tell me its OK and nothing to worry about.

      
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