Ceramic coating on internal engine parts

[CCPcoatings.com]

Originally Posted by Barry_R

The Mahle coatings are nice parts - they use a phosphate dip on all surfaces and a graphite skirt coating. Not many ceramics are used in OE pistons. You will see hard coat anodizing on some stuff - but its actually to prevent ring microwelding and just easier to not bother masking off the top.

Mahle makes nice stuff, but you hit the nail on the head, most all of the mass produced pistons are using some variant of a graphite of graphal coating on the skirt. It's better than nothing, but it's primary purpose is for break-in as opposed to extended anti-friction properties gained from dry film lubricants. The phosphate wash / etch is used in lieu of blasting / profiling required for both Ceramic dome coatings and Dry Film skirt Coatings.

OE's are actively working on production methods to integrate traditional Ceramic Thermal Barrier Coatings on piston domes, cylinder heads and valve faces..... This is being done in an effort to recover the 30%+ thermal energy currently being lost through aluminum heads and blocks.

As for hard anodized aluminum pistons I thought this was being done to maintain piston shape / integrity, much the same reason companies like Mahle have introduced steel pistons. Never thought of the ring benefits.

Steel Mahle


Anodized


Ceramic Dome / Dry Film Skirts