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I questioned my tach accuracy in my video.
it was shot at 30 fps, or 1800 f/min. I saw the engine start and indicate
about 300rpm, and 6 prop blade blurs show. I sped it up until it started
to die at 1500 rpm indicated.[prop blur shows reverse rotation]. at what
I'd guess was indicating 1000rpm the prop shows as a steady, 2-bladed
non-rotating blur. assuming that the camera is catching the same prop
blade twice, 180° apart, that would be at half the 1800 rpm on the camera,
right? so, 900rpm isn't far from my guess of 1000rpm [from memory based
on how the engine sounded in the video]. same for 300rpm/6
blade blur - 1800/6 = 300 rpm. still seems like a lot of wind for
300rpm, considering my Lycoming idles at twice that speed, but then, I'm
typically inside the cockpit, and the test prop 68x66(?) [from a 150hp
rv-4].
I intend to run it without the prop in a week so
I can check my timing without endangering my life. the msd ignition box
has 3000/6000/9000rpm limiter pills which can assist in keeping limits,
altho the trailing ignitions have none. I can attempt to run the ignitions
separately, no idea if it will run that way at this point. another option
would be to tow it over to pineapple racing and hear what rob golden has to
say. they are just on the other side of the
airport.
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