I once heard a story about a crew chief who was trying to explain how nitromethane makes so much power in a top fuel engine to somebody who had no grasp of the volatile liquid’s behavior. “If you pour some out on the counter here and drop a match in it, nothing will happen. The match will just go out,” he began, much to the bewilderment of the new fan. “But if you hit it with a hammer, it will blow a hole in the counter and probably stick the hammer in the ceiling. It’s pressure that makes it so powerful, not so much the temperature.”
Of course, heat is actually required to ignite the fuel, but the point he was making was without the extreme pressures found inside a fuel engine the fuel is basically no more volatile than tap water. However, as you can see in the video below, there are times when all it takes is a little nitro and a little pressure to cause some major issues.
These explosions are caused by nitro being present in the cylinder when the starter is engaged, which compresses the fuel unexpectedly. With nowhere to go safely, the explosion forces its way out of the engine in whatever way it can, which usually means through the thin gap between the head and block, taking the head gasket with it and causing an ear-splitting, shrapnel-slinging explosion that can cause injuries to anybody standing in the wrong place at the wrong time.
Luckily, any injuries caused by these explosions were relatively minor, considering they could have been much, much worse. This video is a great learning tool and warning for all nitro teams so they know what can happen if they don’t take every precaution to clear the fuel from the engine before they fire it up. Of course, we know several of those teams now and know they always respect the nitro at all times, so hopefully we won’t see any more of these clips in the future.