It's sorcery! Burn the witch!
Very cool transducer. Real steampunk vibe going on. Wonder what the theoretical maximum output of this particular contraption is, given optimum fuel and localized cooling fins, as you suggested?
Also, doesn't this seem like an infernal contraption that would be right at home in Bioshock?
Their use of combustion engines for powering robots and stuff always confused me. It's a poor choice for an enclosed environment with recirculated air.