Engine coatings

[LQ1]

My p&p heads are finished and ready for payment and some other final touch up work before they go on my car. I have been looking into some engien coatings, mainly thermal barrier and friction coatings. I dont have the time/money to take the engine out and do the pistons, so i plan on coating the combustion chamber and the valve faces with the thermal barrier. Then I want to coat the cams/valve guides with the friction coating.

So, my question is, if I coat the combustion chamber and valve faces, protecting them from heat, will that put more strain on the pistons heat wise?

[Lyle's GTP]

You have the wrong idea, about the combustion chambers. You want as much of the heat reflected back into the combustion chamber as possible. That's how you make your engine more efficient. Using polished top pistons and polishing the tops of your valves and combustion chambers.

As far as coating for anti-friction purposes, Pioneer preformance makes a great grafite spray on lubricant. All you do is clean your frictional parts with acetone then spray them with this stuff. They recommend camshafts, valve guides, valve stems, crank mains/throws, piston skirt's, cylinder walls, etc. Also in our case you should also spray the camshaft bearing journals as well. I guess it couldn't hurt to do your lifters and lifter bore's as well.

I believe that the stock pistons in our cars are polished top already. So, unless you change to hypereutectic pistons or install a under-piston oil jet kit, you've done all you can. If you are running close to stock power, I can't see any problems.

Lyle

[Gemmer]

any thermal barrier product designed to be put on pistons and valves will reflect heat

[Lyle's GTP]

In this application wouldn't it just increase the heat tranfer to the cylinder head? Then this would lower the cylinder temps, and increase the over-all engine temps. Because unless it's reflecting heat by the means of a "reflector" isn't it absorbing the heat. I beleive the most efficient way to reflect heat is to use a mirror.

..........Or maybe I'm smokin' Crack-Cocaine.

Lyle

[LQ1]

I think your smoking crack, because the thermal barrier coatings keep the heat in the combustion chamber, and prevent it from being absorbed by the valves, combustion chamber and pistons. Thus, creating better power, because heat is energy and energy is power. If it stays in the cylinder, and off the components, its keeping the power where it needs to be.


EDIT: and actually I am looking at the coatings sold by www.techlinecoatings.com

[Lyle's GTP]

Yeah, I know all that stuff. This must just be a metallic-ceramic compound. How ever does it work better than polishing? They never mentioned that. If you can remove the casting flash and sharp edges that is what will help the most. That shit just acts like a heatsink. I actually read in a KB catalogue, that a polished combustion chamber and valves, plus hypereutectic pistons can yield up to a 6% gain in power. Hey, here's a plan....do both! Polish it and then coat it. What ever heat that makes it through the "barrier" will be reflected by the polishing. Just a thought.

Lyle

[LQ1]

Im not sure if this has anything to do with it, but i read an article that had more info on this in hod rod magazine this month. They did an experiment(sp?) on a couple aluminum pistons. They rigged up a welder to hold a constant head in a constant spot on a piston to see how long the piston would last before failure. An uncoated piston i believe lasted around 25-30 seconds before a hole was punctured. The coated piston lasted 90 seconds.

As of now, i dont have the space/time/money to replace the pistons in my car, which is why i asked if the coatings to the valves/combustion chamber would put more strain on the pistons heat wise.

[jmgtp]

Also in our case you should also spray the camshaft bearing journals as well.

Camshaft Bearings... ?

[SappySE107]

A thin layer of carbon will also keep the heat in the combustion chamber and help keep the head cooler. If anything, i would only have the exhaust valves coated if they aren't up to the task of handling the heat...ie boost. The friction modifier would be nice, but the thermal coatings make as much sense to me as cryo treating everything on an NA car.

[LQ1]

I guess i did forget to mention the part about adding boost to my car, and the coating on the valves to eliminate detonation.