850HP Ford BOSS 429 Motor Goes ‘BOOM’ on the Dyno

Nobody likes watching their hard work explode in a hail of sparks and shredded metal. But watching other people’s stuff explode? Now that’s fun. The bigger the engine and the bigger the explosion, the better. Things get even better when you’re talking about 800 horsepower big-block engines where everything seems to go wrong all at once.
This video, found by Bangshift, shows a 557cui stroker motor on the engine dyno during the 7th run of the day. Then, as you might expect, something goes terribly, terribly wrong.
There isn’t much information on this video, but we do know what the catastrophic failure was. This is a Ford BOSS 429 motor, stroked out to 557 cubic inches. As you might imagine, this went along with a number of other engine improvements that pushed the engine to over 850 horsepower. This particular dyno run was the 7th of the day, and made 850 horsepower just before the explosion.
The failure of this motor was due to the stock BOSS 429 flywheel. The builder did not wait for the proper billet flywheel, and on the 7th run the flywheel exploded. The exploding flywheel went through the bellhousing (blowing ut up), cracked the engine block (ruining it), went right through the headers (destroying those), and then went through a wall and into the next room. That’s one hell of an explosion.
It looks like it may have even knocked the engine right off of the stand. While it all makes for a great 30 seconds of entertainment, we can’t help but feel a bit bad for the fellow who put all the work (and money) into this motor. Patience is the lesson of the day, kids.