Push rod tube painting, Is it OK Options

[whitey]

I'm repainting my engine tin and resealing the engine...is it OK to paint the push rod tubes or do they need to left alone for cooling or ?

[brer]

not that it makes a difference but..

flat black has an emissivity of .97-.99 which is one of the highest of all finishes, but it has a 1:1 ratio between emissivity and absorptance, so it will absorb heat at the same rate.

white (depending on brand of paint) can have up to .92 emissivity. Not really much of a difference comparatively with black, but it has a 3:1 ratio Em/Abs with only .22 or so absorptance.

In a hot environment white can sometimes be a better choice due to the fact that it sheds heat quickly but is not absorbing other radiation resulting in a cooler object.

What is important is the equillibrium temperature the object has, basically the balance between its absorption and emission. White will always have a lower equillibrium temperature than black.

Not that it makes a bit of difference though in this situation, like I said.


Dont polish your engine case though, as that will drop the emissivity from about .20 for oxidized aluminum down to about .03 or less depending on how much time you spend with the Mothers.

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