I was thinking about when I rebuild my engine I wanted to paint the block black, will this affect the cooling or does black not affect as much when your at those temps? You know black is supposed to absorb mor heat? I don't know just something that crossed my mind.

 

Very, very, very negligible difference with paint color in relation to heat exchange. The internal heat of the motor is cooled by the cooling system. The outside doesn't matter unless it is an airplane motor or VW or Porsche air cooled motor.

 

thermodynamics guru types talk about the fabled 'black body' in discussions of heat transfer as the ideal radiator...a 'flat black' surface is considered the best RADIATOR of heat from a hot object to cooler surroundings...polished chrome plating retains the most heat by a wide.... dark colors DO absorb heat more than lighter colors WHEN the 'other thing' is HOTTER.

homes heated by those 'ol fashioned' cast iron radiators in each room find noticeable poorer heat in any room where the radiator is painted a light color.

fyi: rough aluminum surface (cast or particulate blasted) radiates TEN times as much heat to a cooler body as a polished aluminum surface...painting aluminum retains heat, and rusted iron holds less heat than painted iron altho a thin coat of paint over bare iron is nearly the same.

in summation: if you have an aluminum engine, don't paint it (unless corrosive atmosphere is a problem) and if your engine is iron and you desire paint vs 'ugly' go thin/flat black.

polished alum rocker (valve) covers and a chrome oil pan can raise your oil temp to the danger zone, vs 'rough cast' rocker covers and a flat black steel oil pan that will be 'cool runnin' in the same environs.

 

Thanks so a little black on the LT1 will not hurt a thing.

 

I painted mine black, no problems.

 

There is no way you will ever notice a difference, no matter what color you paint it.

 

I heard some people paint the underside of the intake manifold white to lower temps.Does this work?Doubt it.I asked a similar ? as the OP awhile back & what I got from everyones answers is that black does absorb heat when directly in the sun but very,very,very little in the shade.Most people paint their blocks black to hide dirt.Not much cleaning to keep the block black.But if the block was painted white for example it would fade,discolor,& show dirt & oil leaks-not much of a problem with black.Also keep in mind that some paints can be an insulator-ceramic I believe?

 

I didn't paint mine black because I figured it would be difficult to track down any potential oil leaks.

I was right

 

I like lemon yellow, the oil leaks show up better. Chartreuse is almost as good.