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<DIV>In a message dated 5/23/2005 10:00:28 AM Central Daylight Time,
patterndude@comcast.net writes:</DIV>
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<DIV>I've gotten a lot of recomendations to add a carbon lightweight 4-stroke
pipe to our lineup so I'm starting to look at a 4 stroke pipe design. I
have some questions:</DIV>
<DIV>1. What are the proper pipe inlet diameters that you desire on
pipes</DIV>
<DIV>2. Worst reasonable case: how close is the pipe to the exhaust port</DIV>
<DIV>3. What max temperature at the inlet do you suspect (I'll be doing
detailed research on this but want your opinion).</DIV>
<DIV>4. Is it possible to tune a 4 stroke at all, or is the muffling the only
goal? If tuning is possible, how does this work?</DIV>
<DIV>--Lance</DIV></DIV>
<DIV> </DIV>
<DIV class=signature id=signature>--<BR>District 6 AVP
<BR>www.aeroslave.com</DIV></FONT></BLOCKQUOTE></DIV>
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<DIV>Lance</DIV>
<DIV>Inlet o.d. 5/8"( See my note on this below.)</DIV>
<DIV>outlet o.d 7/16"</DIV>
<DIV>Some dim's that I use</DIV>
<DIV>1. Center of exhaust port to end of header 4"</DIV>
<DIV>2. Teflon tube distance from end of header to inlet of muffler 6" (Shorter
Teflon tubes may result in Teflon tube or header failure, the Teflon tube
becomes very flexible when heated this relieves the forces on the header.) Tube
used by most is 3/4" od x 5/8" id. Shorter tubes are definitely a problem and
cause header failure, It is also very important to let the system warm up after
start to allow the Teflon to become flexible, If you don't you will experience
tube and header failures.</DIV>
<DIV>3. Distance from inlet of muffler to the muffler including the pipe
section and inlet cone 4"</DIV>
<DIV>4. Muffler tube length less inlet and outlet cones and tubes about
16"</DIV>
<DIV>5. Outlet cone and tube 3"</DIV>
<DIV>6. O.D. of muffler 1-1/2" ( I have no idea where the baffles are
located or what they look like) </DIV>
<DIV>The system is just a muffler, not a tuned pipe.</DIV>
<DIV>Temperatures of the exhaust are fairly hot running high nitro fuel in a
properly tuned engine the temperature will get to +/- 400 deg. on a
unturned engine running lower nitro temp can exceed the Teflon tube limit and
cause failure of the tube.</DIV>
<DIV>In your design I suggest a slightly larger inlet tube Say 11/16"o.d. with
an aluminum tube insert molded in. Others without it have a high failure rate.
this will require that the Teflon tube be expanded with heat to install. Some of
the ones I have have a 3/4"o.d. inlet that makes it very difficult and almost
impossible to expand and install the Teflon tube.</DIV>
<DIV>Last but not least keep it light. If you want them to sell they must
be lighter than aluminum versions </DIV></FONT></BODY></HTML>