Mailing List flyrotary@lancaironline.net Message #50713
From: Mike Wills <rv-4mike@cox.net>
Subject: Re: [FlyRotary] Re: FLIGHT DATA 1
Date: Tue, 30 Mar 2010 20:25:21 -0700
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Well that’s just not fair after all the hassle I went through to get mine to run.
 
Mike Wills

Sent: Tuesday, March 30, 2010 7:52 PM
Subject: [FlyRotary] Re: FLIGHT DATA 1

As another data point, we recently put together an engine stand to take to the Contact Magazine alternative engine roundup in Jean, NV last weekend.  The engine is a 1987 13B NA with the stock automotive intake and injectors.  The MAP sensor lines were connected to the dynamic chamber with no damping elements.  The engine ran perfectly at all throttle settings using the default EC2 parameters with absolutely no tuning.  Static RPM with the reduction drive and propeller was 5000 rpm.  I don't know how that propeller compares with those normally used.
 
Steve Boese  

From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of Tracy Crook [tracy@rotaryaviation.com]
Sent: Tuesday, March 30, 2010 8:13 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: FLIGHT DATA 1

Those are not good places to get the manifold pressure from for the very reasons you are saying.  The best place is in the plenum chamber just after the throttle body.  I have never experienced the bouncing MP that others have experienced when using that location.  I have a fairly long silicone hose to the EC2/3 which may also help but there is nothing wrong with the small orifice & accumulator that some are using.

Tracy

On Tue, Mar 30, 2010 at 7:56 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:
I bought a couple of fuel filters today.  Before I install them I have a
couple of questions.
I have two taps into the intake manifold about an inch apart.  Each of these
taps connect to completely separate lines(one of them has a "T" in it which
goes to the fuel pressure regulator) which go to the two separate inlets on
the EC-2. These two lines are probably of different lengths, and the one has
a "T" in it.  So any pulses could get to the EC-2 at different times even
though they originate from the same place.
Question:  should I "Y" these two lines together into the same filter and
then back out and separate them to go to the EC-2 so the pulses are more
"homogenized" between the two inlets to the EC-2, or keep them separate as
before?
Is this going to slow down the response to a throttle change and cause the
engine to "bog" when the throttle is first opened?  It occurs to me the
factory probably solves this problem with the throttle position sensor which
we don't have.

I am interested in Tracy's take on this since he knows how his system
operates.  I am assuming that we need to do this in the first place because
his system calculates so fast that the pulses cause a problem???

Bill B

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Steven W. Boese
Sent: Tuesday, March 30, 2010 10:07 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: FLIGHT DATA 1

I used small fuel filters in the MAP sensing line.  I soldered the end
closest to the intake manifold shut and then drilled a small hole through
the solder.  This hole was small enough to cause instability (surging) of
the engine at idle.  The hole through the solder was successively drilled
larger until the surging stopped.  The resulting damping system has been in
use on my plane for several years now.  I haven't tried removing it to see
if the upgraded EC2's don't need this.  It's been long enough that I can't
remember what size of hole I ended up with, although that would be easy
enough to measure next time the cowl is off.

Steve Boese


________________________________________
From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of
Bill Bradburry [bbradburry@bellsouth.net]
Sent: Monday, March 29, 2010 9:37 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: FLIGHT DATA 1

I have heard of others using some kind of expansion chamber like this, but
Don is the first I have heard of including a restriction in the line as
well.  He got an improvement with the restriction before he added the
expansion chamber.  I wonder if both would be needed to dampen out the
pulses?

Bill B

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