Gloss black engine components - absorb too much heat?
Thread Starter
Burning Brakes
Joined: Jan 2001
Posts: 959
Likes: 1
From: Plano, Texas
Gloss black engine components - absorb too much heat?
I'm considering painting the valve covers, plenum and runners gloss black. In doing so, will I absorb too much heat? It's either gloss black, or candy red.
Burning Brakes
Joined: Nov 2001
Posts: 1,241
Likes: 9
From: Houston TX
Re: Gloss black engine components - absorb too much heat? (StephensblackL98)
if the engine is bathed in sunlight it will probably absorb more heat than it radiates. if not, it will actually radiate more heat than white. a perfect "black body" radiates energy proportionally to the 4th power of its temperature. anything less than a perfect black body will radiate something less than that.
(this is why radiators are painted black.)
-michael
[Modified by MSR, 7:58 AM 2/12/2004]
(this is why radiators are painted black.)
-michael
[Modified by MSR, 7:58 AM 2/12/2004]
Burning Brakes
Joined: Oct 2002
Posts: 983
Likes: 1
From: Bergen County NJ
Re: Gloss black engine components - absorb too much heat? (StephensblackL98)
Short answer - No, go for black if that's your first choice.
Technical answer - Black won't make much of a difference, especially on the aluminum components, which will heat up due to conduction. Black is only a factor when considering radiation heat transfer, which isn't the dominant heating mechanism here.
Technical answer - Black won't make much of a difference, especially on the aluminum components, which will heat up due to conduction. Black is only a factor when considering radiation heat transfer, which isn't the dominant heating mechanism here.
Burning Brakes
Joined: Sep 2001
Posts: 1,013
Likes: 9
Re: Gloss black engine components - absorb too much heat? (StephensblackL98)
Black paint helps both heat emission and heat absorption. For power production the discussion should focus on the intake manifold and runners.
To answer this question, you just need to know whether the underhood air temp is higher or lower than the intake manifold temp. If it the underhood air temp is higher, paint it silver. If it is lower, paint it black.
To answer this question, you just need to know whether the underhood air temp is higher or lower than the intake manifold temp. If it the underhood air temp is higher, paint it silver. If it is lower, paint it black.
Melting Slicks
Joined: Oct 2002
Posts: 3,193
Likes: 1
From: Cincinnati Oh
Re: Gloss black engine components - absorb too much heat? (VictorRussell'92)
I would go with the age-old question of: Which looks better, and how much more expensive is it?
So if the black and red paint costs the same... then go with black. :D
So if the black and red paint costs the same... then go with black. :D
Racer
Joined: Mar 2000
Posts: 311
Likes: 0
From: Houston, Texas
Re: Gloss black engine components - absorb too much heat? (StephensblackL98)
Altho I haven't done it to the LT1, we have painted Ford and MOPAR drag engines flat black for years after the research shows a measurable increase in heat transfer with black. The comment about aluminum and the fact you are talking about a street engine probably means if you like gloss black, go for it, but you won't notice much of a difference.
Burning Brakes
Joined: Oct 2002
Posts: 983
Likes: 1
From: Bergen County NJ
Re: Gloss black engine components - absorb too much heat? (Mr6spd)
Black paint helps both heat emission and heat absorption. For power production the discussion should focus on the intake manifold and runners.
To answer this question, you just need to know whether the underhood air temp is higher or lower than the intake manifold temp. If it the underhood air temp is higher, paint it silver. If it is lower, paint it black.
To answer this question, you just need to know whether the underhood air temp is higher or lower than the intake manifold temp. If it the underhood air temp is higher, paint it silver. If it is lower, paint it black.
I'm missing your point. The difference in air temperature will drive the convective heat transfer and the color of the surfaces has no bearing. The color of surfaces will determine the radiative heat transfer, and the difference in temperatures between the manifold/runners and the underside of the hood is important.
From a convective standpoint, if you want to cool the intake/runners, then make sure the air under the hood is cooler. From a radiative standpoint, if you want to cool the intake/runners, paint them black (so that they emit) paint the underside of the hood black (so it absorbs) and make sure that the underside of the hood is at a lower temperature so that heat flows toward it.
[Modified by sraft, 8:28 PM 2/12/2004]
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Burning Brakes
Joined: Jan 2001
Posts: 959
Likes: 1
From: Plano, Texas
Re: Gloss black engine components - absorb too much heat? (sraft)
Wow! Thanks, guys. I interpret all this as the bottom line is that I'm not going to see much difference with black components. Gloss black it is! Again, thanks for your time.
Melting Slicks
Joined: Nov 2003
Posts: 3,375
Likes: 1
From: Northern CA
Re: Gloss black engine components - absorb too much heat? (StephensblackL98)
Paint thickness can be more inportant than color. Also gloss is a poorer rediator than flat. In the end, it won't make much difference on valve covers.
Instructor
Joined: Jun 2003
Posts: 205
Likes: 0
From: Broken Arrow OK
Re: Gloss black engine components - absorb too much heat? (xs650)
Black is what you need to release heat. Gloss black will retain more heat than flat. Light colors and shiny metals (chrome valve covers) reflect heat back into the engine.
That's pretty much it in layman's terms.
Bry
[Modified by bry593, 6:15 PM 2/13/2004]
That's pretty much it in layman's terms.
Bry
[Modified by bry593, 6:15 PM 2/13/2004]
Le Mans Master
Joined: Jul 2001
Posts: 6,252
Likes: 2
From: Silicon Valley Kalifornia
Re: Gloss black engine components - absorb too much heat? (StephensblackL98)
Studies show black "releases" more heat. Keep in mind not to apply too much paint because you will in effect be "jacketing" the heat inwards. If thermal efficiency is your goal, apply one coat of black over the bare metal.
