the conrods and crankpins can only handle so much stress. short bursts they can sustain just fine, but if you hold it WOT for too long with a lean HSN, like a race tuned engine has, the engine will overrev beyond is physical limits and grenade. it has to do more with the weight of the piston, wristpin, conrod weight/strength ratio than anything else. that piston may be light, but getting it to change direction while occillating at 40,000+ rpm requires a LOT of force. throw into the mix that there is less lubricant in the engine due to a leaner mixture to get to those kinda speeds and its even harder on the internals.
there are 2 kinds of tunes you can put on your engines, and you can't get them mixed up for what your doing with them
there is a racing tune, which has a lean HSN to get your car to max speed by the end of the longest straight, with a rich LSN to keep temps down and to keep the bottom end from going soft in long mains.
and there is a bashing tune. which has the HSN set to limit your top speed to a reasonable limit by being on the rich side of peak power, and a lsn tuned a little leaner to retain the snap off the line.
if you bash with a racing tune, blown motor for sure, it will overrev and throw a rod, or lock up, or overheat if your lucky. if you race with a bashing tune, you will get walked all over the track because the other guys are setup to run fast on the track and your car doesn't have the room to get up to full speed.
and yes, OS makes a wankle engine for airplanes.
