Webra 160 pipe tuning

[wgalligan]

George,
 
You should be running more of a load on that setup.  !7x12 reg or 17x13
APC with a slightly longer pipe setting.  Inconsistent or peaky needle
settings are typical of too short of pipe or not enough load.  If you
can put the engine and pipe on a test stand start out with the pipe
extra long and shorten it about ¼ inch and record the peak rpm each time
you move it in.  When the peak rpm flattens out or drops then back the
pipe off about ½ inch and it should be just about right for in flight.
You can experiment a little shorter or longer after you see how it runs
in the air.  Lengthen the pipe if it is fat in the midrange.  Larger
props will want to run on a longer pipe and less loaded props will need
a shorter pipe.  Assuming your pump and needles are set properly.  Don’t
set the pipe for absolute peak performance as it will then suffer in the
midrange where you use the throttle most of the time anyway.   Too short
of pipe will also be hard on glow plugs.  My OS 1.40 will turn a 17x13
APC comfortably in cooler air so your 1.60 should handle the loads just
fine. 
Good luck.
 
Wayne G.
 
-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]
On Behalf Of George Kolotouros
Sent: Thursday, October 14, 2004 7:56 PM
To: discussion at nsrca.org
Cc: George Kolotouros
Subject: Webra 160 pipe tuning
 
I have a webra 160 AAR in my new eclipse with a es composites
2c160L9 long chamber carbon fiber pipe. My distance from the glow plug
to the first baffle is 21.75 in. The motor is new. It was running lean
even though we were running rich on the ground. Could it be my pipe
length is short? Im running a 17-12 apc N and running 15% cool power
fuel. Any thoughts on this matter would be greatly appreciated.
Thanx. George
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