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<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff size=2>That's
right, Bob.</FONT></SPAN></DIV>
<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff size=2>The
hopper needs a fair bit of air in it, which is exactly counter to the use of a
hopper in order to de-bubble the engine run near the end of the main
tank.</FONT></SPAN></DIV>
<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff size=2>It is
only good in the short term, but that's OK. It helped in my 1/3
Laser.</FONT></SPAN></DIV>
<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff size=2>Many,
many moons ago, Kavan sold a pressure carb for the popular 60s of the
day.</FONT></SPAN></DIV>
<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff size=2>The
one for the Enya 60 (hey, Phil Kraft won the World Champs with one just the year
before!) had a </FONT></SPAN></DIV>
<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff
size=2>bicycle valve biult into the side of the carb, attached to a fuel nipple
that was plumbed to a tank vent.</FONT></SPAN></DIV>
<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff size=2>A cam
attached to the </FONT> <FONT face=Arial color=#0000ff size=2>throttle arm
would open the valve below 1/2 throttle and burp the
tank.</FONT></SPAN></DIV>
<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff size=2>Of
course, if the plane was interted, it would pee out the side of the
carb.</FONT></SPAN></DIV>
<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff size=2>I
spent hours in the backyard, annoying the neighbors and trying to get that thing
to transition consistently.</FONT> </SPAN></DIV>
<DIV><SPAN class=038565020-02122004><FONT face=Arial color=#0000ff size=2>No Sir
... didn't like it.</FONT></SPAN></DIV>
<P><FONT face="Times New Roman">Dean Pappas</FONT> <BR><FONT
face="Times New Roman">Sr. Design Engineer</FONT> <BR><FONT
face="Times New Roman">Kodeos Communications</FONT> <BR><FONT
face="Times New Roman">111 Corporate Blvd.</FONT> <BR><FONT
face="Times New Roman">South Plainfield, N.J. 07080</FONT> <BR><FONT
face="Times New Roman">(908) 222-7817 phone</FONT> <BR><FONT
face="Times New Roman">(908) 222-2392 fax</FONT> <BR><FONT
face="Times New Roman">d.pappas@kodeos.com</FONT> </P>
<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> discussion-request@nsrca.org
[mailto:discussion-request@nsrca.org]<B>On Behalf Of </B>Bob
Richards<BR><B>Sent:</B> Thursday, December 02, 2004 3:46 PM<BR><B>To:</B>
discussion@nsrca.org<BR><B>Subject:</B> Re: OS 160FX
setup<BR><BR></FONT></DIV>
<DIV>Running crankcase pressure was a very good thing for control-line
engines. I had a ST .15 that would not run well without it, but ran great in
every attitude with it. </DIV>
<DIV> </DIV>
<DIV>One problem with RC application is the fuel metering of the an RC
carb does not work well with the pressure. Also, when the crankcase pressure
drops as the engine idles down, there is a good chance that raw fuel can run
back from the tank and into the crankcase, which will flood the engine. With
muffler pressure, a little raw fuel in the muffler won't hurt anything. If you
put a one-way check valve in the pressure line, then you won't get the
variable pressure to the fuel tank that you really need for the carb to work
well.</DIV>
<DIV> </DIV>
<DIV>I've used one of the Cline regulators, and it seemed to work very well,
but I did not get a chance to use it very long. I was testing an MVVS .61 for
pattern. (Great engine!). One problem was that the carb had to be modified
slightly. The carb was designed for muffler pressure, but the Cline regulator
reduces the fuel pressure to atmospheric. I had thought about running a
muffler pressure line to the vent (atmospheric) side of the regulator
diaphragm, but never had a chance to try it out.</DIV>
<DIV> </DIV>
<DIV>For the life of me I can't understand how the hopper tanks work. If the
main tank drops 6 inches, then you still have to pull fuel from 6 inches, with
or without the hopper tank. The only way I can think of it working is if
there is some air in the hopper, then momentary changes in the main tank
height won't be felt at the carb, but extended up/down lines would be. Still,
it seems to work, and may be the route I would go. I like simple.</DIV>
<DIV> </DIV>
<DIV>Bob Richards.</DIV>
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