Why is one 340 connecting rod bronze color?

mguner said

Crank Works - CWI Pro Rods

Heat Treatment
Our rods start with a copper plating of the non-critical areas. They are then heat treated to stringent specifications by a Nadcap, ISO, and AMS certified heat treating facility. This process substantially hardens the rods for increased strength. From there, the rods are stripped of their copper plating so that they can be properly shot-peened.

Click to expand...

Apparently nobody bothered to read this or follow the link so here it is again...... They remove the copper before shot-peening so it is done to all rods prior to heat treating so that only the bearing and pin holes get surfaced hardened from carburizing and the rest of the rod will bend before breaking.... Apparently some of the OEM rods skipped the removal process and or shot-peening. The proper way to size rods is simple and would be a lot cheaper than copper plating. Think about it. If the rods were "dipped" then the cap and rod mating surfaces would be covered too (defeating the purpose of adding metal)and still require machining which is the way to resize the rod anyway.....