Any advantage to coating or painting the INSIDE of the intake?

For reference purposes, this is regarding the LT1 Aluminum. Not a carb manifold or composite type. It is at the Powder Coating shop and they were discussing that it is a BAD idea.

Since this board knows port flow, thermal characteristics, and volumetric efficiency... I'd go here first.

For intake manfiolds there a a few coatings.

Thermal Barrier Coating is one that is good for the inside, so is flow coat offered by Swain. When you are trying to keep the heat out of the intake and out of the air/fuel charge a thermal coating is the way to go.

As for the powder, since there is a boundry layer of air it probably wouldn't hurt anything. The fuel will not eat it up so you don't have to worry about that. It's not going to effect much but it will trap some of the heat in the intake cause it slows down the heat transfer from the aluminum to the air.

Bret

So you're saying it will keep the heat "in" the intake... which is just the opposite of what I want it to do. I was hoping to pick up velocity. But, not at the sacrafice of high temps... especially if there is a blower someday...

Originally posted by Wild1
So you're saying it will keep the heat "in" the intake... which is just the opposite of what I want it to do. I was hoping to pick up velocity. But, not at the sacrafice of high temps... especially if there is a blower someday...

Remember thaer is zero velocity at wall of a port, at least at the molecular level. Super smooth doesn't help...and may actually hurt. Size and shape are probably much more important than smoothness.

Since there is no veloctiy at the intake walls, it helps to have a rough surface, as the Strokers were saying.
What I have always done with my intakes, and intake ports after porting, is use either 80 or 100 grit sandpaper rolls and roughen up the intake walls. Don't get to aggressive, just enough to give the fuel and air all "scratched up", which will aid in fuel distribution. But since this is a LT1 application, this would help more so on the intake ports in the heads.
Then I would apply a thermal barrier coating on the undeside of the intake to block heat from the engine, while on the top of the intake, apply a heat reflector to keep heat from the engine bay from going into the intake form above
Now if you wanna get really fancy......this company makes intake coolers, which basically adds a streamlined bulb of aluminum in your intake tract, which has a CO2 line running through it, pumping liquid CO2 (very cold) through it, chilling the aluminum bulb down which in turn absorbs heat from the incoming air and cools it.
Their website is:

www.designengineering.com

Heres the intake link:

http://www.designengineering.com/cryo2_cryogenic_air_intake.html

Hunter