Valve cover color effect on heat and power

[4gfun]

I am sure that it won't make much of a difference but I was reading that flat black radiates heat best....but won't that heat up the engine bay a bit more?

Which is more important for power? A cooler engine bay or a valve cover being able to release heat?

I know that we are talking tiny amounts but still want to know. Getting ready to paint my Valve cover so wanted to know.

Thanks

 

[knochgoon24]

It's not enough of an effect to worry about.

 

[Ravenous]

Man, we are talking such a negligible nuance here, paint it what ever color you like. The first time you tell somebody you painted your valve cover based on performance they will just laugh at you. That being said, a cooler engine bay is always preferred as long as the motors internal temperature is warmed up enough to get into closed loop.

 

[PieEyedPiper]

If a little paint on an intercooler has negligible impact then I'm sure your valve cover will be just fine.

 

[bradselph]

Ignore the fact that it almost wouldn't be worth it to do it but i would say black would hold in heat and white wouldn't.

You go stand out in 100* weather with a black shirt on then a white one and you tell me what one felt better.

 

[isantop]

Ignore the fact that it almost wouldn't be worth it to do it but i would say black would hold in heat and white wouldn't.

You go stand out in 100* weather with a black shirt on then a white one and you tell me what one felt better.

Black converts more light into heat, but it also radiates said heat better. Black, in this case, would be cooler since there isn't really any light in the engine bay.

The first time you tell somebody you painted your valve cover based on performance they will just laugh at you.

Quite frankly, that sounds exactly like something a DSMer would do...

 

[4gfun]

So if black radiates heat better, that wouldn't be the right choice then for a cooler engine bay correct (which is more important the temperature of the valve cover? I know the difference is minute, but most of us bother with things that are minute. You all can laugh, I'll survive.

 

[greekgodchaos]

Strip it, polish it, be done with it. You should save about 0.0069oz in weight by not painting it. because racecar.

 

[bradselph]

Strip it, polish it, be done with it. You should save about 0.0069oz in weight by not painting it. because racecar.

shave the letters off for that extra 1/8th pound

 

[curt-s]

There won't be any difference regardless of colour. Are you sure you're not referring to reflection of infrared light and its efffect on temperature? For instance, wearing a black shirt on a sunny day makes you feel about fourty five billion times hotter than if you were to have worn white.

Yellow valve covers do make you go faster though.

 

[gabytech]

If a little paint on an intercooler has negligible impact then I'm sure your valve cover will be just fine.

Regular paint will limit the intercooler cooling capacity, but thermal dispersant coating will benefit an intercooler, radiator, cylinder head, brakes, etc.

thermal dispersant messing around - Subaru WRX Forum: WRX Forums. Read this thread...

 

[underradar92]

If the air around the item in question is cooler than the item and there is no radiant heat source (exhaust, turbo, etc.) nearby then a dispersant coating (or well chosen paint color) will aid in removing heat from the item. The additional heat should be removed through whatever airflow exists under the hood. Underhood air temps are less the effect of the valve cover (close to that of the oil temp, 250-280*F-ish?) than all the other 1500* stuff in a DSM engine compartment.

What is the air temp near your valve cover? No idea? I have no idea either and we are all just speculating.

Yellow valve covers do make you go faster though.

 

[4gfun]

Thanks all...leaning toward the yellow valve cover...but the paint will need to be lightweight. Definitely want to remove the lettering though to save weight! Good fun and good thoughts so far.

 

[dsmTripp]

No haven't you all heard its the neon pink with purple cheetah print that makes you go faster....

On a more serious note unless the op has everything maxed out on his car and is striving for those 1/10 seconds being shaved off of his time the paint choice and the weight savings gained from shaving his valve cover wont make an impact.

 

[PieEyedPiper]

Regular paint will limit the intercooler cooling capacity, but thermal dispersant coating will benefit an intercooler, radiator, cylinder head, brakes, etc.

thermal dispersant messing around - Subaru WRX Forum: WRX Forums. Read this thread...

I'll check it out. My sources are smaller scale air-water radiators with a nice layer of paint on them vs bare brass/al/cu and you can hardly ever get two identical setups to deviate more than a degree of each other, even at extremely low and high temperatures. Although the is a difference, doing a little statistical analysis shows just how miniscule of a difference it is.

But I'll still read that link, thanks. I'd be lying if my previous post wasn't designed to be "bait".

EDIT: I wonder if that black junk is expensive.

 

[WES_393]

Is the OP trolling here or what? Can't believe this is an actual thread

It's certainly not the worst thread I've seen this week.

IMO, it's better to keep the heat in the engine and out of the bay. But paint, polish, and shaving will do close to nothing in that regard. So if your really worried about heat, then put a heat shield over the valve cover like so:

(TSIAWD666's Eclipse)

 

[91stocker]

Is the OP trolling here or what? Can't believe this is an actual thread

Well there is a little bit of merit to the thought anyway.

I know the muscle car guys have issues with chromed out bays. Chrome is like a heat shield holding in all the heat. When the entire engine, every accessory and bracket, the firewall, etc are all chrome it can be hell keeping her cool.

 

[4gfun]

Good info, I like the shield and have heard that about chrome. If paint color doesn't matter then I'll just go with some rustoleum high temperature paint.

I really like the shield though.

 

[greengoblin]

It's certainly not the worst thread I've seen this week.

IMO, it's better to keep the heat in the engine and out of the bay. But paint, polish, and shaving will do close to nothing in that regard. So if your really worried about heat, then put a heat shield over the valve cover like so:

(TSIAWD666's Eclipse)

LMFAO

That is a rain sheild. That is the only reason that is on his car.

 

[4gfun]

Well I do have a vented hood.

LMFAO

That is a rain sheild. That is the only reason that is on his car.

 

[GSLENK]

Someone just learned about emissivity in their physics 101 class, and is trying to apply it. (to a place where it shouldn't be applied)

 

[WES_393]

LMFAO

That is a rain sheild. That is the only reason that is on his car.

Are you saying it does nothing to reduce engine bay temps? If so, you've obviously never put your hand near the valve cover of a warmed up engine (sarcasm).

Maybe that wasn't his intention, but it's a much better idea than using paint to reduce temps.

 

[jasonleee09]

I did my 3kgt valve covers flat black with high temp paint from autozone and it didnt make any difference. It did look pretty sexy to .

 

[AWD1997TALON]

This thread is awesome!!

The shield works both ways. It doesn't appear to be designed to act as a radiator or heatsink so as it heats up beneath the "raincover" where is the radiant heat going to go?

Too funny.

Probably would work better as a heat shield if it were mounted between the exhaust manifold and valve cover with some intertermediate thermal barrier that won't act as a hot plate after the engine is shut down. i.e. gold/ceramic.

Oh ya, save some weight too shave those letters off! Hahaha.

 

[rx7ttlm]

It's certainly not the worst thread I've seen this week.

IMO, it's better to keep the heat in the engine and out of the bay. But paint, polish, and shaving will do close to nothing in that regard. So if your really worried about heat, then put a heat shield over the valve cover like so:

(TSIAWD666's Eclipse)

I don't think people understand how heat transfer works. The valve cover, cover for thermal issues is about the dumbest thing I have seen. For that to be effective in ANY manner, it's probably more for keeping water out of the spark plug galleys so you don't have a misfire with a vented hood.

OP, don't worry about what color to paint things. There are about 100 other ways you can screw up your tune/ engine performance before the paint color. I am certain that if I did simulations I MAY be able to quantify a difference in color. Worry about that after you have new plugs, a good tune, boost leak tested and found 0 leaks, cold air is coming into the intake rather than engine bay temp air. The color will fade anyhow so just paint it whatever you feel like and then you will likely come back and change it again in 2 years when it fades or changes color.