Ha ha, your pretty funny, you stole this pic from a vintage snomobile site off of google... This piston burned up cause of a shorted spark wire..

Google Image Result for http://www.snowridermag.com/snowmobiles/images/piston-1.jpg

The thing is that there are plenty of cars that dont and never had a knock sensor and there are new cars today that dont have them, they are a fail safe to keep the engine from allowing the car to detonate when it thinks that its going to pre-detonate.
As long as you take care of your car and not being a retard, any car can run just fine with out a knock sensor. None of the pre computer cars had a knock sensor and they all seemed to run just fine.