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[grc]

Just compared oil temps at the digital dipsticks on my 2004 SEEG and my bud's '07 Ultra(standard model): same load,route. His is new presumably with mineral based oil, I'm using Mobil 1 V-twin. His oil temp was 33degrees hotter! We always compared temps on his recently departed '03 Ultra and he ran consistenly only 4 or 5 degrees hotter. One of the things that he is complaining about on the new bike(and there are many!) is the heat coming off the motor, which is black.

OK, let's try this from a different angle.  Suppose you have two metal objects that have both been heated to the same temp.  One is black, and the other is silver.  Since black is the best emitter of radiant heat, placing your hand next to the black part will probably result in it "feeling" hotter than the silver part.  However, if you actually measured the internal temp of each part, you would find that the black part would cool more quickly.  The black part "feels" hotter to your hand, but that is only because it is radiating more of the heat away from the actual part.

Jerry

[SPIDERMAN]

Jerry,
         Remember Cool Hand Luke ?  Strother Martin played the warden and spoke this famous line

  "  What we have here is a failure to communicate "  

 [smiley=huepfenlol2.gif] [smiley=huepfenjump3.gif]

   B B

[EZRIDN]

In my opinion, black would run cooler.  Black absorbs energy and re-radiates heat.  

We always painted our racing engines black because every other racer did in the hopes that the engines would dissipate heat better than any other color...maybe that's an old wives tale but, they still do it today.  

Automotive radiators have been painted black forever to dispense heat.  Can't say as I've ever seen a white/light colored radiator.   Heat sinks are usually black...except for the cheapy ones that are natural material color.  

BTW, ever notice the heat shields on the bottom of the Space Shuttle....black.   I can't think that NASA would be preferring that color over another just for appearances.

I asked one of the Harley factory dudes why the MOCO went with the silver color on the Screamin Eagles motors in the first place...his answer was it was intended to be in keeping with tradition of the original H-D motors which were natural or silver looking...much as in keeping with the overall 40's style of motorcycle which remains so popular today.   There is no reason for the bikes to look like they do today other than to continue to be a recognizable figure (tradition)....which every other manufacturer has since mimicked.  And very much so with the V-twin engine design (the imperfect masterpiece).  The v-rod being the exception.  Why they now went with the black color...I imagine that it is because they got tired of being asked why they went silver.  I personally prefer the black as I suspect most other people do as well....which could lead to increased sales.

Anyway, getting back on track....maybe need to ask a bunch of old wives and get their opinion on the color question.    

[HUBBARD]

I beg to disagree here.

[EZRIDN]

Yo there ... to old friends and appologies for not logging on for so long! Guess I have been riding a lot ... European HOG Rally in Ireland and all.

Anway on to my question ...

Is it silver or black engines that run cooler.

Regards
Tony

So Tony....do you have Guinness bet going on with friends over this question?

[Tony - www.1700cc.co.uk]

So Tony....do you have Guinness bet going on with friends over this question?

Nope ..... just want to build my next bike with the most technically correct components.

[Twolanerider]

Which color motor is coolest?  Soon it will be red.

[fatboyse2]

fatboyse2,
 

[Fired00d]

Which color motor is coolest?

[Tony - www.1700cc.co.uk]

My question is a serious one.

My memory of school physics recalls that black absorbs radiated heat such as the sun better. Hence light coloured cars are more desieable for passenger comfort in hot climates. But does that mean that black also dissipates heat better?

I do intend to go for diamond cut cylinder fins to increase surface area and wind turbulence for cooling. I am also going for extra oil coolers.

I thought that Hubbard might have the answer ...

[Twolanerider]

My question is a serious one.

My memory of school physics recalls that black absorbs radiated heat such as the sun better. Hence light coloured cars are more desieable for passenger comfort in hot climates. But does that mean that black also dissipates heat better?

I do intend to go for diamond cut cylinder fins to increase surface area and wind turbulence for cooling. I am also going for extra oil coolers.

I thought that Hubbard might have the answer ...

Tony, just a suggestion but it might be worth a call to the proverbial "horse's mouth" of color options to see what they say.  

www.sumax.com

Since they can go almost anything so far as colors and acceptable materials are concerned they'll have no vested interested in one over any other.