Painting T Barrels

DavidPorter · 01-05-2004, 06:02 PM

I am building a 2.4 using 85mm JE pistons and bored cast iron barrels (and a big box of Pelican parts). Is there any benefit or detriment to painting the barrels? If it doesn't hurt I'd be tempted to slap on some black BBQ paint just to keep things neat and keep the corrosion at bay, but I don't want any negative effect on heat radiation . I know people used to paint VW cylinders black, but I'm not sure why.

Thanks.

Wayne 962 · Wayne 962's Garage

This has been debated. There are coatings that you can place on the cylinders. Satellites have their equipment painted black to radiate heat, but this is a slightly different application. I think the consensus is that if you don't pick the right paint, it can end up acting as an insulator, and actually increase your temps by not allowing the air to cool the cylinders. I would leave them alone - your not going to see them anyways...

-Wayne

HawgRyder · HawgRyder's Garage

If you do paint the barrels...use heat conductive paint.
Harley used to sell it...I haven't seen any or needed any for some time.
It was very thin...had to go on in several coats....and baked on inbetween coats.
The whole idea is to increase the heat conduction of the metal...if you use regular paint it will just hold in the heat (insulate) and blow up the engine.
Bob

cnavarro · 01-06-2004, 01:25 PM

Use something like technline coatings thermal dispersant. A pint w/ shipping runs ~$90-100. When I rebuild cast iron cylinders (overbore and nikasil), I usually paint them with dispersant.

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precison Performance

SC-targa · 01-07-2004, 07:13 AM

The hotter it gets, the more effective flat black paint is as a radiator. On something that runs cool, there is very little difference. I'd say go for it. Your oil coolers are usually painted black, though AC condensors are not.

Regards,

Jerry Kroeger

kstylianos · 01-07-2004, 08:35 AM

Try here:

http://eastwood.com/itemdy00.asp?T1=10040+Z&I1.x=25&I1.y=65

oneblueyedog · oneblueyedog's Garage

It's well known that VW guys paint them black. Flat black!

Thermal dispersants are the trick way to go. Try Performance Coating Specialties. 817 274 1947. Michael Tomlin owner.

Eagledriver · 01-07-2004, 07:00 PM

While it's true that black paint will increase the heat loss due to radiation our engines aren't cooled primarily by radiation. They are cooled by conduction to the air being blown through the fins. Any coating that puts a barrier between the aluminum and the air will decrease the heat loss. Besides Wayne said to leave them unpainted.

-Andy