ktcanuck:

Yes, that is the O.S flex pipe. I believe that there are actually 2 lengths available 170 mm and 120 mm from them (tower Hobbies) including a cast 90 degree header that will fit the RCV 120 SP. Do a search on O.S FS-91 surpass accessories on the Tower Site, or, click here:
http://www3.towerhobbies.com/cgi-bin...0p?&I=OSMG2624

Both ends are threaded on these pipes (11X75 Same as the 120SP) and they come with a jam nut on both ends. The tube is made from a solid tub and, as such will hold pressure and gasses along its length. The end you see on my tube was made by me (last minute before a flying event in an attempt to get airborne) as I needed to exit the gasses out of the engine bay and also needed to use pressre from those gasses to pressurize the tank and prime it on first run. The nipple is made by me after the stock muffler and brass nipple simply sheared off along with the mufflers (2) due to the vibration loosening and then chewing up the threads on both mufflers from this engine and same parts from my newer engine in the Spit. I realize the 120SP does not have a lot of pressure it generates as the RPMs are not as high as other engines but, the bit it does help on fuel delivery to the carb in my set up. I threaded it and then Silver Soldered it to my exhaust stack, it won't vibrate or shear off now! I would like to move it up the tube as I know the pressure would only be greater there. Unfortunately, so would the heat as well so, Ill make a new pressure nipple which will be longer with cooling fins at the base of it to keep the silicone from burning off. I had that happen on the break in runs on the bench. And, when it did, it changed my high and low needle settings. Not so good if you are flying......