Mike,
You should get more power at WOT if you richen the mixture from stoich
while at WOT. I was wondering the other day about how much control over
mixture the knob gave us. The answers I got indicated that if you were at
stoich at 12:00 oclock, then best power should be around 1:00-2:00 oclock.
After that you should start getting black smoke and then maybe bog??? Let
us know…
Bill B
Sorry for the delayed reply again. My bad for creating
confusion with my comment re stoich at full throttle. To clarify, stoich (as
displayed on my narrow band O2) at full throttle with the mixture knob
centered, but I can drive it off scale rich by turning the knob. Not sure if I
can richen it enough to bog the engine.
----- Original Message -----
Sent: Friday, October
16, 2009 5:35 AM
Subject: [FlyRotary] Stoich
A/F Ratio?? : [FlyRotary] Re: where's the missing power?
Hi Mike,
I guess I’m missing something - If
your mixture monitor shows stoich at full throttle, then it’s not solely
an airflow problem – it appears to me that it’s the lack of
sufficient fuel. IF you are at stoich 14.7:1 A/F ratio then that means you have
more oxygen available in your system to support burning more fuel = more
power. You should be able to enrich the mixture particularly at
full throttle (assuming you are wanting full power at full throttle) to around
12.65:1 air/fuel ratio for best power. I know you know all of this - that
is why I am puzzled by your statement that you feel it’s an airflow
problem when on the surface with the Stoich ratio it would appear it’s a
lack of sufficient fuel.
Ed.
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Mike Wills
Sent: Thursday, October 15, 2009
11:22 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: where's
the missing power?
Sorry for my absence on a topic I started. My nephew
had a skateboarding accident last weekend and is in the hospital in a
chemically induced coma until his brain swelling is under control. And I
thought car powered airplanes were dangerous. Stay away from skateboards.
Tracy - My
mixture monitor shows stoich at full throttle. I suspect an airflow issue
rather than fuel.
Al - my vacuum gauge is located in the plenum directly
behind the throttle plates.
Lynn - I agree
that the TB inlet is horrible and needs a bell mouth. The inlet is also pretty
obstructed by the cowl which isnt visible in the pics I sent. I think I'll make
an attempt to clean this up some and see if it gets me anywhere. If not I'll
live with it for a while.
Kelly - always tough to determine if the problem is an
engine issue or if the load is simply too much for the engine to overcome. I'm
going to experiment with the shallow dive several have suggested and see what
happens.
----- Original Message -----
Sent: Tuesday, October
13, 2009 4:21 PM
Subject: [FlyRotary] Re:
where's the missing power?
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Al Gietzen
Sent: Tuesday, October 13, 2009
7:22 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: where's
the missing power?
I dont have a regular manifold
pressure gauge, just an industrial type vacuum gauge ( I really gotta get an MP
gauge). Anyway, the vacuum gauge was indicating 4" of vacuum.
Where are you measuring the 4”
vacuum? If it is near the ports it is no unusual; if it is out before the
runners; something is wrong.
Al
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