Hello Dick,
Living in the UK, I have read and heard that the J'EN engines are pretty reasonable stunt engines. Obviously they are converted RC engines, but converted by Just Engines themselves. The engines are made to Just Engines spec by a Pacific Rim manufacturer. The quality is very good indeed. These engines are not PAs or RoJetts, but never the less, at least one Brit expert uses them in F2b. On a value for money basis, they are hard to beat. The only thing I can't stand is the purple and black colour scheme!
Regards,
Andrew.