In Part 1 of “The Big Bang Theory,” we asked the question: What causes catastrophic nitro engine failures in drag cars? We addressed this question to a few well-known racers and tuners. In Part 3 we speak to infamous tuner Austin Coil.
Austin Coil, Hall of Fame Tuner of the
Chi-Town Hustler and John Force Nitro Funny Cars
“I believe it is rare that the driver is at fault. However, if the engine is grossly over-revved when smoking the tires, or if he stays in the throttle after it is obviously hurt, he must share the blame.”
“I find it hard to use the term ‘tuner failure.’ This is a game where many of the facts are not known, unlike sorting through an airplane crash where the systems needed have been documented for years. Tuning is a practice, a lot like medicine. You learn as you go.
“That said, the great big boomers I have had experience with usually start with an event. The type of thing old-timers uniformly call ‘hydraulic.’ A true hydraulic is virtually impossible when the engine is running.
“What happens is a high volume detonation. After a misfire or two a cylinder may contain twice as much fuel as normal but still only one-tenth of what it would take to hydraulic. Usually it just does not fire, but sometimes, if the temp, pressure, turbulence, etc. are just right, it goes off violently in a supersonic flame front known as detonation. That will blow the heads off the block, the crank out the bottom—whatever is the weakest link.
“If no reason is obvious for this, then the tuner must modify the combination (cam timing and cylinder head flow are critical) to make this less likely. I feel that if it happens less than once every 200 runs or so you may have to accept it as fuel racing.”
“Failure of valvetrain components can trigger an event. If the valves don’t open on time, all bets are off!”
Doug Herbert’s All-Time Engine Explosion
The Doug Herbert explosion at the 1999 Winternationals is generally acknowledged as the most violent and impressive engine explosion in drag racing history. No one knows the exact cause, because there wasn’t anything left to examine.
Luckily, no one was seriously injured by the blast that scattered engine pieces a thousand feet in every direction. One spectator sitting at the 1,000-foot mark had the injector barrel valve land near him and returned it to Herbert. That was one of the largest pieces found. In addition to the engine, the car was also a total loss. Larry Frazier was the tuner of record.
In summation, there are many factors that come into play, and it is often difficult to determine the exact cause. What is known: These ground-shaking blasts are expensive, awe-inspiring, and unfortunately, the results are sometimes life-threatening.
There are many factors that come into play, and it is often difficult to determine the exact cause. What is known: These ground-shaking blasts are expensive, awe-inspiring, and unfortunately, the results are sometimes life threatening.
Text by Jeff Burk
Photos by Jere Alhadeff, Gary Nastase and Marty Reger