I went out to the airport this afternoon to try
to add some flywheel weight to the single rotor. Installed
longer AN-7 bolts, each with an additional 4 larger washers, and 5 small
washers. This added about
26 ounces to the flexplate, at the 4 dampener bolt locations.
Unfortunately, it didn’t change a thing wrt the vibration
issues, or prop oscillation. Still shaky around 1000 rpm, severe drive
rattle around 1900-2000 rpm (can't bear to try to find the exact
range), and severe vibration from 2500-3100. From 3300 to
5000 it's pretty smooth, but with the scary prop oscillation getting
worse and worse as the rpm increases.
Not sure
what to try next. I do have
a two blade IVO prop that I could try in place of the 3 blade
Warp Drive, but I’d
have to cut the blades down from 72” to 68” to clear the fuselage
tube. The torque reversals might not be the best
thing for an IVO prop either. I’m starting to fear
that someone’s going to get a deal on an RD-1C drive while I look for
another solution, and build an
RV-8.
I’m
still finding that I don’t have enough fuel at anything above idle. I was actually having to run the
cold start, and mixture above 12:00 to have a mid range O2 reading at 3000-4000
rpm. I set mode 3 today,
and kept raising the fuel until I got a mid range reading with the
mixture at 12:00, and no cold
start engaged. This took 24
clicks!!! Something just ain't right here...
Before I
started today, I checked the fuel pressure using a mighty-vac pump to
simulate changes to the MAP line.
The regulator changed pressure just like it’s supposed to.
I made
myself a note to check the fuel pressure calibration again the next time
I go to the hanger. I set
this using a different sensor, that I believed to be the same as the one
that’s installed on the regulator.
That should have gotten me very close, unless I accidentally used
a sensor that was different (30 psi rather than 80 psi for
example). Once I had the
fuel pressure “calibrated” on the EM-2, I used that reading to set the
adjustable regulator for 42 psi.
Maybe my pressure "reads" 42 psi, but is really way low, like 15
psi or so.
If the
fuel pressure is correct, I’ll have to look into the injectors
themselves. They’re 400
cc/min MSD injectors, just like what was on the RV-3. These were ordered just for
this, and never used on anything else, so maybe I was sent something
smaller than 400 cc/min.
Worst case, I have a pair of 525’s that I can install if
needed.
Ah, the fun begins. Pity I don't
have time to fiddle with this much now. The QB RV-8 will be here
soon.
Cheers,
Rusty (the
weather geek)
PS- The following link is the weather station in my
back yard. The wind gust readings don't seem to be reporting
correctly by the Weather Underground software, but otherwise, it's
pretty cool. My hope is that we'll never get another hurricane,
now that I'm set up to record the wind conditions.
http://www.weatherunderground.com/weatherstation/WXDailyHistory.asp?ID=KFLNAVAR7