21A rods set up on a 4" Merc crank

[Bored&Stroked]

They are copper-bronze bearings . . . it isn't just a "look" it is the material. They are hard and they tend to wear the crank journals more than the cadmium-silver (Heavy Duty Truck and Bus) bearings that I prefer.

Many of the bearing manufacturers (including Ford) made both the copper/bronze versions as well as the "CS" - Cadmium Silver versions. I only use the cadmium silver versions in my strokers running full-floater bearings. They are a lot harder to find than the copper/bronze versions - so I've "collected" a few sets over the years.

Example: Federal Mogul made two versions of rod bearings to fit the 21A rods:

1) CA - copper/bronze
2) CS - cadmium-silver

Part Number Example: 9800CS-30 (.030 oversize).

IMG_1586.jpg

For modern OHV folks, the cadmium-silver versions are similar in concept to some of the Vandervell bearings we run on blown OHV engines with a lot of boost. The goal is to take a bit of shock out of the system and "play nice" with the journals.