Because of the prop rotation control line was originally flown clockwise to keep the lines tight. That would place the Torp exhaust down. Everyone fly's counter clockwise which has a tendency to turn the airplane left. That would place the exhaust up on this Torp. I have many hundreds of flights with that same Torp and could never wear it out. I would occasionally blow head gaskets but I would just cut them out of playing cards. After a 40 year lapse I have come full circle and am building U-control again. I'm starting to look at how to install bellcranks in my RC airplanes.