SAT Question Everyone Got Wrong

[teenix]

I have never searched for anything on UTube from the presenter of the SAT video, but I was looking at UTube this afternoon, and out of the blue there was the same video listed, which is somewhat weird. I failed though, I would have chosen the wrong answer - 3.

If anyone is interested in the engine problem, the answer is fairly simple. Even though the engine and exhaust gas temperatures fall when the mixture is leaned past the peak, any fuel that is still burning is quite hot. Even though it may be hot, the burn is in a smaller area, so the rest of the engine and the exhaust gasses are cooler than normal - less energy overall.

However, if that hot burn is consistently in the one area in the combustion chamber, it is possible that that area gets too hot and can melt metal, ie a hole in the piston. Pre-ignition (pinging) may also occur because of the hot spot which can cause mechanical damage as well. Easy to hear in a car, but not so in a noisy cockpit.

cheers

Tony