[Chris Hill]

Jeff said:

Chris, I admire you for taking the initiative and if proper testing was noted I might be swayed...

That's the thing, I have tested this before. We had another valvetrain that was failing. It would be fine for a couple of hours on the test stand, then it would fail. The valve lift curve showed good seating velocity and no spikes in the velocity and thus acceleration. To double check our data, we bolted an accelometer to the intake valve and retested with new hardware. During the closing of the intake valve, an impact was occuring and the accelometer was showing VERY LARGE accelerations and thus forces. Any safety factor that we designed into the part was then moot. The material on the parts was Stainless steel 316, the good stuff. We even tried making parts out of 52100 (bearing race steel, rockwell hardness of 58-62c scale). The parts still broke with bearing steel. Then we changed the design of our valvetrain to lessen the impact loads, we could use the original Stainless steel material. The issue was not the material of the part or heat treatment, it was just a bad design.


Jeff also stated:

And not trying to get personal, but it's obvious you have failed to understand the parts offered today are inferior to yesterday. Done, end of subject.

And to prove a point, I've used rockerarms purchased at Autozone in 2003, ran them in my v-6 small block Chevy upto 7,200 rpm with out failures. I understand the standard Autozone rocker is not as good as 1967 Z-28 rockerarms. I understand the issue at hand very well and make sure my stuff works in the operating range it was DESIGNED for.

Impact in the valvetrain is breaking your rockerarms, reguardless of the material used for the rocker. If you keep having breakage, figure out what is causing the impact.

The solution is don't run as much rpm, it is that simple.