The X30 Cylinder Cover

Without Cover With Cover

In cold whether, the front of the cylinder is hit with freezing air moving at over 100km/h on every straight. This difference in temperature results in the front of the cylinder expanding less than the rear, putting the engine at a risk of seizing, something exaggerated in the wet, where the shorter gearing means that the cylinder is experiencing these contractions and expansions while locked at 16000 RPM.

Why?