Hi Jim,

I have a ZDZ80RV and a Brison 5.8 and I highly recommend both engines. Both will turn the same prop at close to the same RPM. The 5.8 may have a sleight edge.

I don't know much about the Fox 5.8 but it probably runs very well. They sure are proud of it because it's $145 more than the Brison.

One more consideration is the rear carb on the ZDZ80RV allowing a very clean engine installation. You also need to think about good cooling air flow across the engine. I wrote an article on baffling and it can be found here under the FAQ section. www.rcshowcase.com

Ken

http://www.brisonrcengines.com/ Brison 5.8 $579.95
http://foxmanufacturing.com/WOW.htm Fox 5.8 $725.00
http://www.rcshowcase.com/html/engines/zdz80.html ZDZ80RV $675.00