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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => Project Custom Motobricks => Topic started by: stilbo on August 26, 2014, 09:25:00 AM

Title: Black or 'natural' engine cover?
Post by: stilbo on August 26, 2014, 09:25:00 AM: Engine is on the bench. Can't decide whether to powder coat engine covers black or bead blast and seal? Bike will be "naked" cafe.
Title: Re: Black or 'natural' engine cover?
Post by: pdg on August 26, 2014, 11:31:35 AM: Powdercoat is a fairly effective insulator and the engine loses quite a bit of heat through the casings...

I have almost no opinion on colour :2thumbup:
Title: Re: Black or 'natural' engine cover?
Post by: Kyle10 on August 26, 2014, 01:56:03 PM: Quote from: pdg on August 26, 2014, 11:31:35 AM
Powdercoat is a fairly effective insulator and the engine loses quite a bit of heat through the casings...

I have almost no opinion on colour :2thumbup:

Thank you for that. Been on the fence re the same subject.
Title: Re: Black or 'natural' engine cover?
Post by: F14CRAZY on August 26, 2014, 02:41:00 PM: Back in the day the administrator of the Bonneville Club forum (supercharged 3800 Vs mostly) experimented and found a measurable cooling effect using crinkle finish paint on supercharger housings...
Title: Re: Black or 'natural' engine cover?
Post by: stilbo on August 26, 2014, 04:46:51 PM: Thanks all...
I'm just in the middle of the road from an aesthetic perspective... And I want to decide quickly as I can't go further on the engine until I slap the covers back on.
Thanks again!
Title: Re: Black or 'natural' engine cover?
Post by: TimTyler on August 26, 2014, 05:10:13 PM: Quote from: stilbo on August 26, 2014, 04:46:51 PM
Physics 101... Black absorbs heat.

I know that black absorbs all wavelengths of light, and if the heat source is light, then a black object converts the light energy into heat energy.

But if the heat source is not light, I don't think the color matters.
Title: Re: Black or 'natural' engine cover?
Post by: pdg on August 26, 2014, 05:45:09 PM: Yes, black does absorb heat - it also radiates heat more effectively than silver. The crankcases may well be black but they aren't powdercoated.

The material is what I am questioning, not the colour... A layer of powdercoat will retain more heat in the engine compared to a bare finish or paint - of any colour. It's the material that is doing the insulating.

But hey, whatever - powdercoat it twice in pink for all the difference it makes to me.
Title: Re: Black or 'natural' engine cover?
Post by: stilbo on August 26, 2014, 08:40:36 PM: Funny "pink" was mentioned... I might break out a half pint of Jack Daniels and stare at these covers for a while. A visiting friend told me to "be careful, they might be pink tomorrow".
Title: Re: Black or 'natural' engine cover?
Post by: Chaos on August 26, 2014, 10:21:57 PM: The heat effect of the color is so piddling it doesn't matter. Remember, it's radiating heat not absorbing it BUT if it mattered at all they would have put fins on it like an airhead. You still got the radiator? Don't worry about it. Paint it the color it was when it left the factory, I think they were silver until 87 or 88 then some of them were black.
Title: Re: Black or 'natural' engine cover?
Post by: NickAndHisBrick on August 28, 2014, 09:37:46 PM: "Mighty car mods"on YouTube did a bare vs black intercooler test on YouTube a while back. Their results were quite surprising. But then again an intercooler is thin material and has airflow inside and outside, so their results might not apply to cast valve covers and such.
Title: Re: Black or 'natural' engine cover?
Post by: argent brick on August 29, 2014, 12:10:02 AM: I like the natural silver, myself. What color is the bike going to be when you are finished with it?