Guest Anonymous Posted June 28, 2001 Share Posted June 28, 2001 IF I WERE TO PAINT MY ENGINE ARE THERE ANY SPECIAL COLORS TO GET ANY SPECIAL TRICKS OR TIPS I WAS THINKING ABOUT GETTING A COOLER ORANGE SO I COULD STICK WITH THE GOOD OLD CHEVY LOOK BUT WOULD THIS CAUSE HEAT PROBLEMS? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 28, 2001 Share Posted June 28, 2001 Nah, no problem, Chevy did it for years as did other manufacturers. I'm not sure when the fad for black engines started, it used to be that each manufacturer had they're own engine color. (Reddish orange: Mopar early smallblocks, bluish aqua mopar later small blocks, Dark blue: Ford, Orange: Chevy, Greenish aqua: Pontiac etc..) Just get the crude off the block if it hasn't been hot tanked and stripped down to raw cast iron and spray with a heat resistant paint. I used a 500 deg. duplicolor Black on my water pump on my Chevy engine recently and its holding up real well. I even used its on some welds on the muffler in the back of the car and its handling that ok. I'm not sure where engine paint color effecting engine temperature got its start, I've seen it mentioned in some websites and for the life of me can't see how it would matter if the hood is on the car. In the dark (under the hood) neither Orange or Black are going to show any difference heat wise. Maybe if the hood was off the car and you drove around in the sun, sure black would absorb more heat whereas a lighter color would reflect the suns heat away... Regards, Lone Quote Link to comment Share on other sites More sharing options...
Oltmann Posted June 28, 2001 Share Posted June 28, 2001 quote: Originally posted by lonehdrider: I'm not sure where engine paint color effecting engine temperature got its start, I've seen it mentioned in some websites and for the life of me can't see how it would matter if the hood is on the car. In the dark (under the hood) neither Orange or Black are going to show any difference heat wise. Maybe if the hood was off the car and you drove around in the sun, sure black would absorb more heat whereas a lighter color would reflect the suns heat away... Regards, Lone Looks like someone has forgotten their quantum theory. The color of an object does affect it's emissivity, although texture is generally much more important. Relative to the theoretical perfect radiator (aka a black body) these paints have the following emissivity: Black 0.96 Blue 0.94 Green 0.92 Red 0.91 White 0.90 These are all very high though. For instance polished Al has an emissivity of .09 (==sucky.) I don't know how much of a difference this will make in engine temperature, however if the manufacturers use it then I'm sure it has some impact. Quote Link to comment Share on other sites More sharing options...
spotfitz Posted June 29, 2001 Share Posted June 29, 2001 quote: Originally posted by Mike kZ: This is how I did my lime green engine. [ June 28, 2001: Message edited by: Mike kZ ] Which looks sweet!! BTW Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 29, 2001 Share Posted June 29, 2001 .06 emissivity difference? Whats that translate into HP? I think they just got a hellava deal on black paint... Regards, Lone Quote Link to comment Share on other sites More sharing options...
DavyZ Posted June 29, 2001 Share Posted June 29, 2001 I seriously don't believe that color will make a rat turd of difference with all things considered for our purposes (sorry Oltmann not trying to be nasty, I just couldn't think of anything better than "rat turd" ). As far as painting the engine, Lone is right: get the engine really clean before scuffing it and fogging it. You can use Castrol Superclean on the nasty stuff, or even oven cleaner (keep all these things away from aluminum) and then follow up with lacquer thinner or 3M oil & grease remover, etc. I'd scuff it with a 300 to 400 grit and then wipe it down again with lacquer thinner. Then I'd fog it with some good quality engine paint. I bought some great stuff at the local auto paint & trim shop. It covers very well, looks almost "thick," holds gloss very well, and flows oh so sweetly. Davy [ June 29, 2001: Message edited by: DavyZ ] Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted June 29, 2001 Share Posted June 29, 2001 You don't have to use engine paint. If you want to paint your engine the color of your car, clean the block (discribed above), then spray etching primer, then a good base primer, your body color base coat, then a clear coat over that. This is using Base coat/Clear coat urithane. This is how I did my lime green engine. [ June 28, 2001: Message edited by: Mike kZ ] Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted June 29, 2001 Share Posted June 29, 2001 Thanks Spot!! Quote Link to comment Share on other sites More sharing options...
fl327 Posted June 30, 2001 Share Posted June 30, 2001 someone told me once that black makes a little more horspower for some reason or another, maybe something to do with heat>? me i dont believe it, and i dont believe that high heat enamel makes a difference that much, i go rustoleum every time, its the toughest paint there is, but i dont give a rat turd about that, or bolt ons for that matter, except nitrous!! yes, i saw fast and teh furious Quote Link to comment Share on other sites More sharing options...
TimZ Posted June 30, 2001 Share Posted June 30, 2001 Okay - Oltmann is correct in saying that the black paint will making the block closer to a blackbody radiator. However, the thing that most people overlook when making this argument is that the vast majority of heat transfer that takes place in the engine bay is through convection, not radiation. Convective heat transfer is when you transfer heat by bringing it into contact with another medium (aka, blowing air over it). Radiative transfer is the type you get when you step out into the sun and feel warm, or if you hold your hand near a light bulb without touching it - notice that the light bulb doesn't get much cooler while it's heating up your hand? In fact, you could make the argument that painting the block any color will decrease the cooling by providing a barrier to convective heat transfer. That said, the effect is probably still nill, since the engine block was not designed to be a heat exchanger, anyway - that's why it's water cooled. So, if you are painting it at all, I wouldn't worry too much about whether the color will make a performance difference. Quote Link to comment Share on other sites More sharing options...
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