I'm finishing up the intake for a 383 I'm building and while I was sandblasting it I thought about applying a thermal coating to keep it cool, which should be easy since nothing runs through it but air. Anybody successfully apply a DIY thermal coating to the underside of an LT1 intake that worked well? I can't keep all the heat out but I figured I could cut it down maybe 50%. I'd most likely do a thermal coating in the combustion chambers as well since the top end hasn't been assembled yet.

 

You might consider a plate or cover on the bottom of the LT intake to keep the hot oil away from it. You could use a non-metallic material which conducts less heat than the aluminum.

An insulating coating would be useful, as you suggest, but could still transfer heat to the aluminum.

It's probably been done. 50% might be a stretch, however.

My $.02

 

What could be used to do that, something like a carbon fiber shield? How would you keep it on the intake manifold?

 

Never tried this as a DIY project. But in general, the gains form something like this are small. The sort of thing to consider when you are looking for the last couple of HP. You would need to sandblast and thoroughly degrease the surface before applying the coating if it's going to have a decent chance of adhering.

Rich

 

On my freinds motor that we just built , we had Airborne coatings apply their coting to the complete intake manifold (outside), then we used a peice of thin sheet metal and built a baffle that bolted on top of the factory sheild thats on the bottom sid eof the intake, not really sure what we were expecting..lol, but in my warped mind I do beleive the intake after a run is slightly cooler than on mine with nothing but natural finish and factory stuff...lol.

 

there are a couple schools of thought here.
1) coatings generaly speaking are for appearence sake on a street car. Pistion coatings and theraml coatings on a race car may give you that tiny edge you need to win when all things are equal. Or will direct the heat where you want it for endurance engines, engines that run at full power for hours at a time.
2) putting a shield inside the intake to reflect heat away from the intake may actually cause your lifters and the surrounding areas to become much hotter and have a tendency to cause oil film strength to be weakened.

Just points of view

 

Get a cowl hood. My intake is always icy cold well same as outside air temp.

 

Just looking to keep the thing cool and I guess 'overbuild' it so it lasts longer. Colder air certainly doesn't hurt and it's one more custom thing I can do. I'll be coating the piston tops as well as the longtubes I'm getting ready to buy. Not really looking for an edge, just something different. Which is why I'm using LE LT1 heads and intake on a 3.8" stroke gen 1 engine I'm also working on a 400 sbc using LT1 FI...you'd be amazed what you could make when cost if a factor. That's my whole philosophy!

 

I wouldn't mess around with the DIY stuff. These guys offer TBC for the bottom of the intake.

http://www.swaintech.com/autolc.html