The application would be an 1/8 scale hydroplane using a 4 -stroke .91 engine. It wouldn't be a raceboat, but I was hopeful I could build a unique model with a more realistic exhaust note. The description on MACK's site says it can handle gas engines up to 1.5 ci but I'm doubtful the nylon gears would hold up. Just a pipe dream for now, I guess. Thanks for input, I appreciate it.