Adding 22 cubes,,, power increase? 528 to 550

gregsdart said
Piston skirt coatings from. Line 2 line are durable like that on modern production pistons. The coatings are also tough enough to allow thicknesses out to .020 (twenty!) over. The coatings are applied thick enough that they reduce piston to wall thickness a lot after run in even. The warm/cool cycles are to get the coating to wear in, absorb oil and take a set so they last. They don't claim any power increase and i suspect that is due to every build being a bit different. Cost me $300 to have them done. Cost goes up as the required thickness goes up.

Right. It's an abradable coating that makes the effective piston to wall clearance about .000 or dang close.

As the engine is run during a relatively short break in period, this coating wears off the piston until the running clearance is established, which is usually tighter than an uncoated piston.

The upshot is this coating allows much tighter piston go wall clearance, making the piston more stable in the bore, and thus, increasing ring seal. The more you can keep the ring belt parallel to the bore surface, the better the ring seal.