Which liar/incompetent ran the dyno?

YES! One thing to watch for is the "correction factor." Corrections are applied to raw dynamometer data to compensate for different conditions at different test facilities. Basically, an engine will make less power as the inlet temperature increases, the humidity increases, and the barometric pressure decreases. There are various ways to "normalize" these effects to some standard condition. There are different correction factors, some of which give grossly overstated power ratings that are rarely seen in the real world (corrections to 60 deg F, zero (!) humidity, 30 inches Hg baro, etc.)  The power rating thus achieved is not very useful for calculating any kind of BSFC. BSFC must be calculated based on OBSERVED hp, not corrected hp. Another trick is getting the hp on a snap acceleration. The engine may produce a few extra hp for a few moments before things heat up, and the dyno may also record an overshoot due to inertia effects. All this is pretty commonplace among the high performance engine promoters.

Jon

 
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