I highly recommend you to use a OS 91FX with stock muffler. It has enough power to pull out of a torqueroll, and it's cheaper than 4cycles engines.
You can watch some videos of mine (please, click right button of the mouse and click on SAVE AS...) :
First: (20MB)
http://www.acro3dvid.com/Elche%20Widebody.wmv
Another:
High quality (38MB)
http://www.acro3dvid.com/Widebody%20...torqueroll.wmv
Medium quality (8MB)
http://www.acro3dvid.com/Widebody%20...ueroll_low.wmv