<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2800.1170" name=GENERATOR>
<STYLE>@page Section1 {size: 8.5in 11.0in; margin: 1.0in 1.25in 1.0in 1.25in; }
P.MsoNormal {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"
}
LI.MsoNormal {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"
}
DIV.MsoNormal {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"
}
A:link {
COLOR: blue; TEXT-DECORATION: underline
}
SPAN.MsoHyperlink {
COLOR: blue; TEXT-DECORATION: underline
}
A:visited {
COLOR: blue; TEXT-DECORATION: underline
}
SPAN.MsoHyperlinkFollowed {
COLOR: blue; TEXT-DECORATION: underline
}
SPAN.emailstyle17 {
COLOR: navy; FONT-FAMILY: Arial
}
SPAN.EmailStyle18 {
COLOR: navy; FONT-FAMILY: Arial
}
DIV.Section1 {
page: Section1
}
</STYLE>
</HEAD>
<BODY lang=EN-US vLink=blue link=blue bgColor=white>
<DIV><SPAN class=321015219-05052003><FONT face=Arial color=#0000ff size=2>Sorry
for the incomplete response, before.</FONT></SPAN></DIV>
<DIV><SPAN class=321015219-05052003><FONT face=Arial color=#0000ff size=2>Most
2-C setups require a lengthening of the pipe to cure the midrange richness or
bog, and to eliminate the power versus throttle position hysteresis that can
plague any piped 2-C.</FONT></SPAN></DIV>
<DIV><SPAN class=321015219-05052003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=321015219-05052003><FONT face=Arial color=#0000ff size=2>The
problem was that if you pushed to level from warmed-up WOT vertical and reduce
to 1/2 throttle the engine may stay "on the pipe" and you get a different power
setting than if you came from idle to the same stick position. Or (and this is a
goodie) you may end up with a level flight cruise setting that changes with what
thermal/load condition the engine was in a few seconds ago, or a lagged settling
time at 1/2 throttle. How about rounding the top of the square loop, pulling the
throttle back, getting a good setting, then 1/2 way across the top of the loop,
the engine falls completely off the pipe, and gets soft.</FONT></SPAN></DIV>
<DIV><SPAN class=321015219-05052003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=321015219-05052003><FONT face=Arial color=#0000ff size=2>The
long pipes fixed that set of problems, and caused the airspeed dependant mixture
problem. O.S. fixed it with a box that looked at RPM versus throttle position,
and corrected the mid-range mixture to get rid of the hysteresis. One other way
to fix ( or at least help ) this would be controlled spark timing; the
other is to make the engine equilibrate thermally much more quickly. As you
know, temp is ignition timing in a glow engine. </FONT></SPAN></DIV>
<DIV><SPAN class=321015219-05052003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=321015219-05052003><FONT face=Arial color=#0000ff
size=2>Dean</FONT></SPAN></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Woodward James R Civ 412
TW/DRP/ACQ [mailto:James.Woodward2@edwards.af.mil]<BR><B>Sent:</B> Monday, May
05, 2003 3:44 PM<BR><B>To:</B> discussion@nsrca.org<BR><B>Subject:</B> RE: 3M
Mintor 170 questions<BR><BR></FONT></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Hi
Dean,</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">I'm still sort of
new. Does W.O.T. = with out throttle? On 45 degree downlines of
medium length like the reverse Cuban eight from the top (Masters sequence),
I'd say the motor just unloads some. If it were lean, it might cut-out
for a second when throttling up. If it were rich, it might gurgle or
give signs of loading up. The 140 or 170 do neither. They just
increase in rpm as the throttle is increased. </SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">On the 140 setup (15%
C.P., 2 OSA5), I needed to lean the low-end screw 1/8 turn during the
2<SUP>nd</SUP> tank on the ground. This setting has held fine since, now
with 1.5 gallons through it. The engines will idle very low, however, I
raise it to 2000 for takeoff and flight. </SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Your technique is the
first I've heard of like this. So, once you get this one flight profile
right, you find a prop that gets the torque you want?</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Jim</SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P class=MsoNormal style="MARGIN-LEFT: 0.5in"><FONT face="Times New Roman"
size=3><SPAN style="FONT-SIZE: 12pt"></SPAN></FONT> </P>
<DIV>
<P class=MsoNormal style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue
size=2><SPAN style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">Thanks
for the response Jim,</SPAN></FONT></P></DIV>
<BLOCKQUOTE style="MARGIN-TOP: 5pt; MARGIN-BOTTOM: 5pt; MARGIN-RIGHT: 0in">
<DIV>
<P class=MsoNormal style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue
size=2><SPAN style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">That
sounds right, though I just like more prop and more
quiet.</SPAN></FONT></P></DIV>
<DIV>
<P class=MsoNormal style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue
size=2><SPAN style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">When
you dive W.O.T at about 15 degrees or so ( simulating using windup for
extremely windy conditions) does the engine lean/richen/or just unload ?
With the 17-13 on the 140, I shortened 'till the richening was gone. That
was just under 1" gap from stock.</SPAN></FONT></P></DIV>
<DIV>
<P class=MsoNormal style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue
size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">Dean</SPAN></FONT></P></DIV>
<BLOCKQUOTE
style="MARGIN-TOP: 5pt; MARGIN-BOTTOM: 5pt; MARGIN-RIGHT: 0in"><P
class=MsoNormal style="MARGIN-LEFT: 0.5in"><FONT face="Times New Roman"
size=3><SPAN
style="FONT-SIZE: 12pt"></SPAN></FONT> </P></BLOCKQUOTE></BLOCKQUOTE></DIV></BLOCKQUOTE></BODY></HTML>