David,

I have never heard anyone report that a BVM 91 overheated in a Dynamax. However, over the years there have been reports that the BVM engine(s) "were never happy" in a Dynamax/Ramtec fan. The BVM engines tend to perform best at the higher rpms that are possible in the Viojet/Viofan. That's really what separates the BVM engine from an OS...ability to opearate at sustained rpm levels around 24k.

Peter