Kevin,
I would not run without the prop. Get a ‘One Touch’
prop rpm device (around $45) . There usually is someone that has one. A guy in
my EAA chapter has one. The local AP would have one.
An example is on page 17 of the April edition of EAA’s
Sport Aviation.
Money well spent!
T Mann
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of kevin lane
Sent: Sunday, April 04, 2010 10:13 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] youtube strobe
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.