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Plenum finish


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So, wide awake at 2am and I get to thinking...

We know that forced induction increases the temperature of the inlet charge, which is why people fit intercoolers, charge coolers and water injection. So, with that in mind, what is the best finish for the plenum chamber?

A polished plenum will reflect heat from the engine, but will also retain any heat built up in the plenum material.

A satin finish will soak up radiated heat but will also radiate eat from itself better than the polished one.

Powdercoating the plenum will be like covering it in a blanket and keep it hot.

I've yet to see a forced induction bike fitted with the 'carb shields' that keep heat away from the carbs, would they be of equal or better efficiency that with a normally aspirated bike?

Given that most of our bikes are cooled by air (yes, even oi boilers) why don't any plenums have finning?

And the final question should i be taking sleeping tablets instead?...

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The amount of work involved for the little heat displacement ‘finning’ up a plenum vs the work involved in adding an intercooler....

...I guess every little helps, i noticed a bit of a difference fitting a decent pipe and a set of 36s to my 1216....15-20 bhp added onto the 120 bhp Ish

 

when I added the intercooler to the 1216 turbo I didn’t notice any difference as it was far too powerful for me anyway....once over 200 bhp on a road is just silly....so fin it, wrap it in gold leaf, add a mini water cooling jacket, water meth injection.....silly is as silly does.

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The best heat dissipating colour is actually flat matt black - about one of the few things I remember from college !..................but it looks shite! And why shield the carbs when they have 160 deg C air belting through them? Stop over thinking and try washing the sleeping tabs down with alcohol - or more if you already do!

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Posted (edited)
Just now, Gixer1460 said:

The best heat dissipating colour is actually flat matt black - about one of the few things I remember from college !..................but it looks shite! 

I guess that depends on what the matt black actually is. If it's powdercoat then it'll not dissipate anywhere near as much as a non-painted one. And I agree in that matt black looks shite ;-)

When I was still on SF I had a tech article planned in which I had several identical pieces of aluminium painted, polished, chromed, coated etc, and then heated them all up to the same temp, and measured which one lost the most heat. And then the mag folded so I never bothered... 

Edited by zedhead
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Best thing I ever noticed any difference with was decently set up suspension and light wheels.....

 

.....and turbocharging 

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Colour does not really have any effect, its radiation (mostly light) that colours absorb/reflect. Actually better off painting it white to reduce radiated heat from outside, but the effect is next to f-all

Finning has very little effect too, the airflow is moving pretty quick and very little heat will actually be absorbed quick enough to do anything useful, if it did have a big affect it would also lower pressure. 

May be worth it on mega performance stuff where every fraction is important but not really worth the effort for a road bike. Fins would look cool though

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1 minute ago, vizman said:

...no wonder your bikes take ages to build el’dervio, so many aspects to tick off the jobs list.

Are they jobs or excuses not to finish?

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53 minutes ago, no class said:

you could look into cerakote or other ceramic coatings to help with the heat issues .

Good on the 'hot' side ie. turbine and exhaust manifold to keep heat in - not so good for rejecting or emitting heat away.

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my bad..... read only the topic  “plenum finish”.... so in this case .... the bare ally will dissipate heat the fastest as any coatings will create a barrier .

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25 minutes ago, no class said:

my bad..... read only the topic  “plenum finish”.... so in this case .... the bare ally will dissipate heat the fastest as any coatings will create a barrier .

Could go for a matt / flat black anodised finish if following the 'black box' theory - probably worth 2/10ths of FA difference LOL!

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So, the crux of the matter is getting heat out of certain components, rather than preventing heat getting in. ie remving heat from the plenum, and not blocking heat from the block from warming it (as an example).

Which leads me to question why so many people have polished up-pipes from the turbo to plenum?...

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33 minutes ago, zedhead said:

Which leads me to question why so many people have polished up-pipes from the turbo to plenum?...

I like shiny :tu

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Because stickers stick better to it el’dervio.....I had a rough cast finish up pipe off a jcb on that blow through chop, it had ‘turbo’ cast into it, worth another couple of tenths of F/A.

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