Engines blow all the time, some more violently and spectacularly than others. Aside from the lost investment in time and money, the most disturbing repercussion is never knowing why.
“It was in the bottom end, but it’s kind of hard to tell what went first,” says Alex Ort, whose 2,500-horsepower 557ci V8 built for his “Bad Attitude” truck puller recently exploded on the dyno at Darren Mayer Performance Engineering.
The engine had been warmed up prior to this initial shakedown run. It was brought up to nearly 10,000 rpm with about 42 pounds of boost from the massive DMPE M5 supercharger when a rod punched a hole in the left side of the billet block. Oil and alcohol sprayed out at the same time the cap was knocked off the magneto, releasing a spark that ignited the fumes. The fireball quickly dissipated after the DMPE crew shut down the engine, and any remaining oil flames were then extinguished.
“It wasn’t an oil or fuel issue,” says Ort, who runs the engine in a 6,200-pound 2WD truck puller. “We’ve narrowed it down to rod failure. There’s a little bit of everything in there, so it’s hard to tell what was first. Some rods had threads, others had the threads pulled out.”
In addition to the window in the block, a total of six aluminum connecting rods were broken along with most of the pistons. The crank didn’t break but suffered plenty of scars. Many of the cylinder sleeves were damaged on the bottom side. Only one intake valve in the No. 1 cylinder was bent from all the mayhem.
Ort says the engine builder immediately flew out to inspect the damage and determined it was not the fault of the dyno operator or setup. He says the builder took back the engine and is building a new one so Ort, a regional champion in 2014, can compete on the national circuit this summer.
“The only things I’m getting back are the valve covers and intake,” says Ort.