[HyperMOA]

Originally Posted by CaberTosser

That explanation is hysterical, the pistons are in constant contact with the cylinder walls and tolerances are engineered in to allow for the coefficients of expansion of the engine part materials. Please,tell us more


A cast iron engine block will not expand as much as an aluminum piston, so the premise that it’s not expanding as fast as the piston would not change regardless of whether the engine was warmed up for 2 minutes or an entire week. The aluminium will expand at roughly twice the rate of the cast iron, so the cast iron cylinder is machined to be the correct size for the expanded piston. There are even expansion rate differences between cast aluminum and forged aluminum pistons so those factors are engineered for as well. Your neighbor only accepted the explanation because he is clueless about engines. Anything more than 10 minutes of warmup is overkill and 5 minutes is plenty.

Can you tell me what shape a piston is at -30C?