I used to design power supplies, with transistors that generated a lot of heat. Of course I had to use a heat sink to keep the transistor junction temperature in the survivable range with the airflow provided and at high elevation and high ambient temperature extremes. This is where I had to learn the intricacies of thermal conductivity, in order to get that heat from the junction into the cooling air and survive without high failure rates. When chosing a heat sink, an anodized aluminum heat sink performed about 40% better than one that was painted. Extra layers of paint made it worse, even black ones.
Black is a color that radiates heat very well. Black anodize was the best performing. Black also absorbs heat, as well, which is something I would have been concerned about if the unit was in sunlight.
Radiators, heat sinks, and cooling fins, all have the same basic functional operation as a heat exchange mechanism.
Go ahead and ignore science if you wish. All that matters to some is how something looks rather than functions. I would not powder coat a heat dissipating cylinder block at the cheapest vendor available without learning about the thermal transmissivity of the finished coating, and the temperature they plan to bake at.
But, if your path is fixed, the cylinder block can withstand about 500F. Do keep the head upright so the barrels won't fall out the top or shift their position in the block. Allow to completely cool slowly before moving it about, and it should survive the ordeal.
Because somebody else did it, is in no way any sort of reasonable justification. Not all human behavior is acceptable to be replicated.
