OS1.40 Pipe > Couplers

[Joe Dunnaway]

Hey Brian,  
    Which pipe did you get?  I've got the same problem.

Joe Dunnaway


----- Original Message ----- 
From: "Brian Young" <b4598070 at yahoo.com>
To: <discussion at nsrca.org>
Sent: Monday, March 01, 2004 10:47 AM
Subject: Re: OS1.40 Pipe > Couplers 


> I remedied the difference in size this weekend w/ a
> new pipe that matches the header diameter. 
> 
> The previous muffler was for a 1.20-1.40 size engine
> but used a 3/4" inlet, headers available happened to
> be 7/8". 
> 
> Anyway, new pipe is lighter and more power just hope
> its not too loud. Couplers will probably survive
> better with same size pipe and header.
> 
> --- "Karl G. Mueller" <kgamueller at rogers.com> wrote:
> > Brian,
> > 
> > If you are using a larger dia. header than your pipe
> > inlet you're
> > restricting the flow of the spent gases into the
> > pipe. What is
> > happening is that you're pushing fresh gases mixed
> > with a certain
> > amount of exhaust gases back into the combustion
> > chamber. This creates
> > additional heat and less performance. A better
> > combination would be
> > same size header or smaller diameter than the pipe
> > inlet. What you
> > want to achieve is a high velocity (more important
> > than volume) in the
> > header.
> > Judging by the size of the pipe inlet you must be
> > using a 10cc pipe
> > which might be a little on the small side in volume.
> > 
> > Karl G. Mueller
> > kgamueller at rogers.com
> > 
> > 
> > 
> > 
> > ----- Original Message ----- 
> > From: "Brian Young" <b4598070 at yahoo.com>
> > To: <discussion at nsrca.org>
> > Sent: Monday, March 01, 2004 10:24 AM
> > Subject: RE: OS1.40 Pipe > Couplers
> > 
> > 
> > > Interesting to see all the solutions to this. Are
> > > these on planes that have exposed or enclosed
> > tunnels?
> > > Same size pipe inlet and header, or different?
> > >
> > > Im particularly interested in the teflon that
> > lasts
> > > for 1000 flights. I think im getting about 50-100
> > > flights per silicone coupler on a 7/8 diameter
> > header
> > > and 3/4 diameter pipe inlet.
> > >
> > > Thanks,
> > >
> > >
> > > --- "Henderson,Eric" <Eric.Henderson at gartner.com>
> > > wrote:
> > > > One of the pilots that I support with OS 1.40's
> > has
> > > > run the cut header set up for three seasons with
> > no
> > > > failures. Also he was breaking headers until he
> > > > changed over to the two-coupler set up.
> > > >
> > > > It is interesting how we get opposing views on
> > what
> > > > appears to be the same situation. I suspect that
> > the
> > > > choice of coupler material and cooling has a lot
> > to
> > > > do with the result. BTW I have had great success
> > > > with 1/16" walled 500F+ Teflon tubing where non
> > > > flexible, but directional, needs occurred.
> > > >
> > > > Regards,
> > > >
> > > > Eric.
> > > >
> > > >
> > > > -----Original Message-----
> > > > From: discussion-request at nsrca.org
> > > > [mailto:discussion-request at nsrca.org]On Behalf
> > Of
> > > > David Lockhart
> > > > Sent: Monday, March 01, 2004 9:56 AM
> > > > To: discussion at nsrca.org
> > > > Subject: Re: OS1.40 Pipe
> > > >
> > > >
> > > > Same experience here.  I've got 2 2.25" rise MAC
> > > > headers that were bent slightly and then cut
> > about
> > > > 1.5" after 2.25" rise.  Both have over 1,000
> > flights
> > > > and no problems with breakage or burning up
> > > > couplers.  Currently using Teflon couplers w/
> > the
> > > > constant tension spring clamps (Central has
> > them).
> > > >
> > > > Dave
> > > >
> > > > ----- Original Message ----- 
> > > > From: mike mueller <mailto:mups1953 at yahoo.com>
> > > > To: discussion at nsrca.org
> > > > Sent: Monday, March 01, 2004 8:48 AM
> > > > Subject: Re: OS1.40 Pipe
> > > >
> > > >  Lance, I have the same problem with the
> > couplers
> > > > burning out when they are too close to the
> > engine
> > > > and I don't have a problem with bending my
> > headers
> > > > the same way Lance does it. Mike
> > > >
> > > > Lance Van Nostrand < patterndude at comcast.net>
> > wrote:
> > > >
> > > >
> > > > I'm not so sure Eric. I've seen people try to
> > cut
> > > > the header in the rise
> > > > and the couplers used kept burning out. the
> > exhaust
> > > > temps are very hot
> > > > there, but cool quickly. You really don't want a
> > > > coupler within 8" of the
> > > > exhaust outlet.
> > > > My suggestion, the solution I've used for years
> > with
> > > > Macs headers, is to
> > > > use an appropriately sized forstner bit (e.g.
> > 7/8")
> > > > and drill a hole in the
> > > > end of a 2x4. Slide in the header and use the
> > 2x4 as
> > > > a bending arm. The
> > > > hole supports the header and the 2x4 gives you
> > > > leverage. Oh, don't leave
> > > > the header bolted to the engine!! Bolt it to
> > > > something else.
> > > > --Lance
> > > >
> > > > ----- Original Message ----- 
> > > > From: "Henderson,Eric"
> > > > To:
> > > > Sent: Sunday, February 29, 2004 7:21 PM
> > > > Subject: RE: OS1.40 Pipe
> > > >
> > > >
> > > > They are hard to bend without kinking. I usually
> > > > cant the engine to the side
> > > > to line up the header.
> > > >
> > > > If it is a MAC, one piece header - no exhaust
> > stub
> > > > and o-rings - it is
> > > > advisable to cut the header half way up the
> > header
> > > > rise, and fit a second
> > > > coupler. This will allow you to rotate the
> > tubing
> > > > and also provide
> > > > protection from header fractures.
> > > >
> > > > Regards,
> > > >
> > > > Eric.
> > > >
> > > > -----Original Message-----
> > > > From: discussion-request at nsrca.org
> > > > [mailto:discussion-request at nsrca.org]On Behalf
> > Of
> > > > Jeff Hughes
> > > > Sent: Sunday, February 29, 2004 7:28 PM
> > > > To: discussion at nsrca.org
> > > > Subject: OS1.40 Pipe
> > > >
> > > >
> > > > Now that I have my OS1.40 mounted in my new
> > focus, I
> > > > find that the pipe hits
> > > > the side of the pipe tunnel due to the right
> > thrust.
> > > > Can I just bend the
> > > > pipe, or should I heat it first?
> > > >
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> > > > =====================================
> > 
> === message truncated ===
> 
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