Why my Chevrolet Corvair decapitated its spark plugs (and what’s next)

Corvair fan in pieces

My 1965 Chevrolet Corvair Corsa has been great to me. Yes, the expected headaches of an old car pop up here and there, but so far no situation has proved too much to handle. The Corvair’s latest mishap, however, was a reminder that parts for the car’s rear-mounted flat-six are old. And with old bits, anything can fail at any time.

The pancake-six in a Corvair is air-cooled. I like that. It makes it easy to put away for winter and I have never had a coolant leak. A magnesium fan sits atop the engine and drives the twin-plane v-belt that everyone will tell you grenades itself like it is going out of style. So far I have never thrown a belt in my tens of thousands of miles behind the wheel of a handful of different Corvairs.

But then my cooling fan self-destructed, which is a whole different problem.

Yes, the 50-year-old fan decided the world was too cruel to go on, and spectacularly shattered into a hundred pieces at about 3500 rpm. Fortunately, the fan was contained under a sheetmetal shroud that kept the high-speed shrapnel under control—but there were still casualties.

Corvair spark plug wires cut from fan
Corvair fuel line cut
Corvair engine top down
Kyle Smith

The top shroud directs the cooling air around the finned cylinders and toward part of the cylinder heads. The spark plugs are located under the shroud, with access holes for service and the plug wire connections. The fan came apart and threw magnesium chunks outward, shattering the porcelain and cutting many of the plug wires. Super! The spinning blade also let go with enough energy to cut through the sheet metal shroud in one spot, not to mention the separate array of new dents in the shroud that hammered the throttle linkage and stuck it open. But wait there’s more! It also tweaked the PCV vent and mangled the oil dipstick.

All of this happened, of course, on what was supposed to be the last drive of the season. Better yet, it all hit the fan (pun intended) as I was backing into the garage, six feet from its resting place for the winter. Why not just quickly blip the throttle to savor the sound of the exhaust before the long winter of silence? My sentence: innumerable hours spinning wrenches in a cold garage.  

It’s a bummer. There are a few winter projects that I want to do, but none that I had to do. Now I have the engine compartment disassembled and am getting caught in the “while I’m in here...” snare. I just have to make sure I don’t procrastinate this time before the Corvair’s annual spring adventure. But on the bright side, better now than the fan failing on the first day of spring.