Solid Roller vs. Hyd. Roller - Pros/Cons?

[Anthony]

Originally Posted by Jamo

I'm trying to understand what you're saying in your second statement. "Factory replacement" of what engine/car? "True" roller cams? As several of us have noted, most factory hydraulic rollers used for the past decade or so in such things as my new Vette do indeed have pressed on iron gears. The hydraulic rollers being used in the FEs generally have them as well, or are hardened steel to begin with.

Excuse me if I'm telling you something you already know, but,

When I say "factory roller", I mean equipped from the OEM car manufacturer with a roller cam, i.e. hydraulic roller, as I don;t know of any cars equipped with a solid roller. I believe all of these cars either had cast roller cam cores, or came with cast iron pressed on gears, compatible with cast iron gears on the distributors, as originally equipped. If some company is going to make a replacement cam for these cars, I would guess they would make a cam compatible with the cars existing distributor, and use pressed on cast iron gears.

When I say "true roller" I mean the "all out competition" roller cams that have been made for decades for performance usage only, i.e. solid rollers, made from billet, steel blanks, with the gears machined from the blank as well. Steel is harder than cast iron, and using a cast iron distributor gear will result in wear necessitating changing the distrributor gear.

That's my understanding.