RE: Found what I needed.
Central Hobbies. They sell the ES Carbon pipe. I use the S8 pipe. 19 inches long. I leave a space of 3/8 of an inch between the header and the pipe. Connected with Aerotrend 3/4 inch tubing. The cheap stuff you won't need the ultra blue. The carbon pipe does'nt really get hot just warm. I usually run the 18.1x10.1 APC prop. Quiet and will take my 11 lb. airplane straight up until out of sight. Running Power Master 15/16 fuel. Also i put the stainless rear bearing from the OS 140 EFI motor. Also the Dual plug head from a 3M Mintor engine with a OS f plug in the center and a KB 1L plug in the rear. Have put approx. 40 gallons of fuel thru this engine and have replaced the rear bearing once and no other work has been needed. About 470 flights.
Dennis