To get back to the tech, doesnt a hypereutectic alloy offer the same advantage chroming a piston would offer, in terms of heat reflection, which seems to be all I could see chroming a piston top would do.
An old buddy of mine who passed away a few years ago was a pretty famous motorcycle engineer, and owned Nitralloy Co. and built sleeved aluminum cylinders for Harley before they did it themselves, and the Nitralloy big bore cylinders. He was an extremely intelligent mad scientist kinda guy, would try anything that made sense in his head. Upstairs in his shop was a separate room where his "what if" stuff was stored, and it was something else. One day he wondered if he could convert a Harley Twin Cam engine to SOHC, so he casted up some new rocker boxes and milled holes in them for the cams, and ran chain drives down to the crankcase- that engine was in front of his desk in the office. He had a very stock-looking Evo Heritage Softail in his garage where the Bonneville bikes were stored that he had de-stroked to 3.5" and would spin 10,000 RPM. He and a buddy had a '37 Indian Scout vintage road racer in a very high state of tune and needed more than 3 gears, and the class was a "stock appearing" deal- so he machine out the inside of the 3spd Indian box and installed the guts of a Harley XR750 race bike trans inside. I feel pretty confident that he would have never seriously considered chroming the tops of pistons. Google "Sputhe". This "Altoona Style" bike made 142 hp and ran 202 mph at Daytona
Chrome plated aluminum was relatively common on chain saw cylinder jugs about thirty years or more ago. I have a Poulan 3800, or maybe 3900 ( built before Poulan became a bad word) with a chrome plated piston. From what I understand, the 3400-3700 models had chrome cylinders, while the later saws went to chrome plated pistons. My circa 1980 or so Jonsereds saw has a chrome cylinder.
The pistons pictured are two piece pistons.. steel uppers and usually aluminum skirts.. I believe they are hard chroming the steel ring grooves and not the aluminum section
The Jalopy Journal
