Yep! any time the drone of the engine
changes - it immediately gets your attention (or should) {:>). I too
have turned on the cold start when meaning to change controllers - but
fortunately have always immediately recognized the problem.
There are several possibilities about
your staging problem.
1. You may not have the cross
over adjustment (mode 6) tuned properly and when it stages its either too rich
or too lean when running on all four. However, adjustment of you manual
mixture control should indicate which direction (lean or rich) helps the
situation.
2. Always possible that a secondary
injectors is not functioning properly - you should be able to check this possibility
easily (if you have the injector disable switches that Tracy shows in his installation). While
on the ground - switch off the primary injectors (you may get a momentary
hiccup if you secondaries are not adjusted properly, but a quick tweak of the
mixture control should keep it running), If it idles/runs fine on the
secondaries then they are likely to be OK.
3. You Fuel Map bin values right
after the staging point could have inappropriate values - Tracy's default
is 128 or I guess it shows up as zero on the EM2 and your adjustments are +- to
that zero reference (128).
You mention the results of
enrichen/leaning was inconclusive - what exactly do you mean? Do you mean
you could not tell if the engine was running rich or lean? The
Air/fuel Ratio indicator of the EM2 is not giving you consistent
readings?
Its pretty important as you know to
be able to discern what effect any adjustments are having and mixture is one of
the more important ones.
You'll get it sorted out - some
installations simply take a bit more sorting out than others
Sent: Wednesday, November
10, 2010 9:51 PM
Subject:
[FlyRotary] Re: Improved performance of my new (2009) intake manifold
Interesting manifold. Are you still using
the VDO fuel pressure sender? I had heard that it might not be suitable for use
with fuel, I am still using mine at present however.
I went up today for a few laps at 3000
over Paine Field. The engine ran well below the staging point, but started
stumbling when above the staging point. It ran smoothly through the staging
transition on the ground, but when in the air I could not tell by the mixture
monitor if it was lean or rich. I tried leaning it out and richening it up, but
results were inconclusive so I stayed below the staging point for the remainder
of the flight. Temps were down around 130 degrees at 4800 RPM and 110 mph, MP
was not noted.
I accidently hit the cold start switch
while on downwind with two other planes ahead of me, the tower told me to go
around on final, but the plane ahead turned off onto the taxiway just in time
so I told the tower that I would really like to land, so they cleared me. The
engine died as I turned off onto the taxiway and then I noticed the cold start
switch. The first order of business was making and installing a switch guard
for the cold start switch. I'm also going to pre-load the switch with a rubber
band so it stays in the off position unless I'm pushing it on, and can just
pull the rubber band off of it if I need to shut down a set of injectors and
run the remaining injectors on cold start.(limp home mode for failed injector.)
The fuel self transfering issue was
resolved by installing manual valve on the transfer line between the tanks.
-----Original
Message-----
From: Dennis Havarlah <clouduster@austin.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wed, Nov 10, 2010 12:27 pm
Subject: [FlyRotary] Improved performance of my new (2009) intake manifold
As some of you know I started flying my
RV-7A with a cut - off Renesis intake manifold. In 2009 I installed an
new intake designed to route pressure waves from the closing of rotor
#1's intake into rotor #2 just before rotor #2's intake closed.
After using the new intake for over a year I am still very happy with it's
performance.
I gained about 15 mph TAS at the same
altitude and manifold pressure
My static engine rpm increased 300 to 350
rpm.
My takeoffs are faster and shorter with
noticeable increase in acceleration
My oil and water cooling is more critical
now because I make more HP.
But - I must confess I don't believe the
manifold can be reproduced economically. It's just too complicated.
I also believe it should have slightly
shorter intake runners to increase the performance at higher RPM.
Decreasing the intake runner length probably would require complete new
geometry of the system.
I have another concept for designing a
Renesis intake that using a reflected wave from Rotor #1 returning to
Rotor #1 .
I believe it would be much easier to
build and small enough to fit into the James rotorary cowl but because my
intake works well I am not moving ahead with completing the design and building
it.