I have 5 Dymanax fans in 4 starfires as well as a scratch built 90 inch/25 lb Canadian Snowbird. I love the Dynamax-OS 91 combinations. I am not sure why people perceive the fan was designed for the smaller OS engines as I know Tom was thinking ahead to larger engines at the time. I am currently running in excess of 15 flights/glow plug. I use his pipe system. I have not had one dead stick in 3 years. I always set my timer at 5 min from takeoff and land accordingly with 1/4 tanks left.

If you are considering fans, I am sure they are both good. For me, I like the Dynamax for its reliability with the OS 91, the JMP system including pipe and mixture, and availability of parts (important these days). Tom is selling fans STILL!!!!

I just had to weigh in with a customer testimonial!

Dave