With a limited number of data-acquisition channels, it's tough to choose what's important.
Last weekend had its ups and downs. It was a race weekend -- which is always good news -- but I had very little time on track, which was frustrating. It also highlighted another use for the car's onboard data-acquisition system that I hadn't anticipated.
In the Sunday morning race I qualified in the middle of the pack. When the green flag dropped I made a heroic, never-to-be-repeated start, passing four cars even before the first corner. As the saying goes, the car went real good right up until it stopped.
Exiting Turn 2 it all went wrong. The engine sounded terrible, I had no power, and had to pull into the pits at the end of the lap. Retirement. DNF. No points.
Turns out I'd bent an exhaust valve. Normally that's a symptom of over-revving the engine. Exhaust valves get awfully close to the top of the piston and if you exceed the engine's red line RPM the two are likely to meet in a less than gentle manner. And so it seemed here.
(Let me digress for a moment to mention that several fellow racers helped me remove the head and replace it before the afternoon race. One guy lent me his spare head, another lent his rocker arms, another had a spare gasket, and two others helped me adjust the valves. I made the afternoon race with 20 minutes to spare. What a great bunch of guys.)
I hadn't remembered over-revving the engine, but who knows? When the red mist rises you never know what you might do. But on Monday I was exonerated. Downloading the contents of the data recorder showed that the engine had never exceeded its rated RPM. I had not bent the valve by over-revving after all.
That doesn't make the repairs any cheaper or less tedious. But at least it removes bonehead driver error from the equation, which makes me feel better.