Geez. If I didn't have bad luck I'd have no luck at all.
I tried to race my car this past weekend and had another bad outing. I drove a handful of laps, then the engine started to feel lower on power, like running on three cylinders. Unfortunately, I didn't think it was a mechanical problem and continued to run the engine. I guess it wouldn't have mattered. Once a valve breaks there's not much to be saved.
Other than the disappointment of not being able to race (after untold hours of prep, towing to the track, etc.), I'm afraid I'll never know the cause of this failure. I don't think it was an over-rev. There is no evidence of the other cylinders' valves hitting pistons. Heck, I wasn't even driving hard yet, although I may have hit 12,500 RPM's a couple of times. The oil pressure was never low. In fact, it was higher than ever (60 lb.) after shimming the relief valve.
I'm using the stock air box, so it's doubtful I ingested anything. I think it's just more bad luck.
For every species of beasts and birds, of reptiles and creatures of the sea, is tamed and has been tamed by the human race. But no one can tame the tongue; it is a restless evil full of deadly poison. James 3:7,8
I have some brand new OEM exhaust valves in the package in your need them.
Thanks for the offer. I'll keep it in mind when weighing options.
I heard two things this past weekend, kinda interesting. These Kawasaki titanium valves start out as two pieces, and are then attached together (I assume via welding). A well respected engine builder says that's where they tend to break.
I also heard that some people prefer stainless steel valves because they tend to bend rather than break.