ORIGINAL: cmoulder
Dan, Gary and others using a tuned pipe,
More info on the coupler from Rendegade who advised me that the stuff he is using is from Purosil, which is an Aussie supplier. Rendegage said that it lasts about 100 flights, is relatively cheap and easy to replace.
Got the specs on the Purosil silicone tubing (SAE J20 R1) and did some poking around today and found a [link=http://www.siliconehose.com/commerce/ccp11370-870id4-ply-silicone-saej20-compliantgl-c40-087.htm]USA-based supplier[/link] of the material, whose specs are SAE J20 R1, which they refer to as ''silicone turbo hose''. The 7/8'' ID size costs $0.83/inch, and I ordered 18 inches of it to try out.
EDIT: price/unit corrected! Thanks, d bodary...
Bob,
If it lasts 100 flights it would be very worthwhile. Regular couplers on glow stuff lasted about 100 flights so that would be on par. I read the specs....apparently the reinforcement is polyester which doesn't have a temp rating more than 400F. I wish they made the right size from the higher temp red silicone with the nomex reinforcement, but they apparently don't. Have you called them? Maybe there is something available not shown on line
I maidened the Extra today. Info on the EF Exra 300 78" thread. My header came off the engine after 15 minutes of flying. I like your solution on the bolts and will likely copy it
Matt