Bulent Aliev wrote:

After almost 3 weeks, my new 2 pipe straight out exhaust is finished.  It is made of 2"  321 stainless tubing. At the end they converge into  one short 4" oval tube. The fancy bends are to make the inside length  the same for each tube. The flange is Racing Beat mild steel. Each  tube has one EGT sensor about 3" away from the exhaust port. The O2  sensor is on only one of the tubes due to lack of room.. My biggest  concern was the noise that it was going to make. I was pleasantly  surprised when I started it in the hangar (John Slade told me it is  OK to do it :). The noise was almost the same as with the turbo  housing on. Saved 30 pounds of weight on the engine and maybe 10  pounds less of ballast on the nose. Did not have time to run the  engine at full tilt, since I'm in the process of making stainless  steel heat shields.
Bulent "Buly" Aliev
FXE Ft lauderdale, FL
http://tinyurl.com/s5xw8

It sure looks nice, but is there any reason for the oval collector? Haven't quite a few others had fatigue failure 'issues' with non-round outlets?


Charlie, I don't think that will be a problem in this case.  Seeing as how the oval is not enclosed, the gases would probably not exert much force perpendicular to the walls.  Now if it were a closed tank, I agree that flexing of the flatter sides would like lead to fatigue and failure.  But, don't see that being problem - unless Buly closes it up to make it even quieter {:>)