I have a Wren MW54 Supersport prototype and have it fittted in a BVM F86 Sabre in a BVM RAM 500 bypass fully ducted instalation and it is perfect.The reason Wren may have said not to fit the engine in a fully ducted instalation is maybe because when this engine was fitted in my sabre 10 months ago it was shuting down at idle and was originaly thought to be a ducting problem, but the problem was later traced to the normally brilliant Hausal fuel pump ( the same one as simjet, jetcat, RAM and many other engines use).Once the pump was replaced it has never stopped and has now logged well over 100 flights and over 12 hours run time.This plane seems faster than my P120 powered S/Bandit with this instalation. My sabre has the standard 1.7L plus the U.A.T and I normaly call landing on 7 mins, land on 8mins and there is enough fuel for a few go arounds and with economy like that and 18LB thrust this engine should be well sort after when its available later this yr.

jason