It is not really that our engines are not "compressed enough". In fact, depending on the engine, our effective compression ratios can be quite high. What tends to preclude pre-detonation in our engines is the small bore size, and the relatively high rpms they run at which are not usually conducive to pre-detonation.

But if you lug even a small bore engine down enough with too much load, get it hot, with maybe a bit of a lean mixture and perhaps the timing a bit too advanced and you will experience detonation and a fried engine just like the bigger engines, if your fuel isn't up to the task of resisting detonation via having a high enough octane rating.

AV8TOR