While much can be gleaned for a racer and engine builder from flogging an engine on a dyno stand, a chassis dyno is the test of truth, if you will, taking into account the parasitic losses of the transmission, torque converter, driveshaft, the third member, axles, and more, to deliver the actual horsepower and torque being put to the tire. Much can go wrong in either scenario, although a chassis dyno involves a lot more moving parts, and additional opportunity for the …stuff…to hit the fan.
Unfortunately for Texas racer Andy Wilabay, it wouldn’t have really mattered how he hammered on the engine in his twin turbo Fox body Mustang, as it came apart in grand fashion at high rpm and under significant boost during a recent pull on the dyno. According to Wilabay, the engine lost a pushrod on the exhaust valve, filling the engine with methanol fuel until the point that it hydrauliced. The force of that occurrence sent what appears to be a breather cap on the valve cover bouncing off the ceiling and death smoke pouring from the pipes.
Fortunately, the damage wasn’t a whole lot worse, but it does serve as a solid illustration of why you don’t want to be congregating around a car on the chassis dyno at full tilt.