[mgarblik]

Originally Posted by Cliff R

Ran ONE set of Scorpions and cracked 13 out of 16 of them. They didn't fail completely but they were a ticking time bomb.

I was being kind about the PRW's above but the failure rate was 100 percent and PRW didn't replace them. Not surprising as with most of these parts you get a really good "Arkansas Warranty" when you buy them: IF you break them in half.....you get both halves!.....LOL

Anyhow, we do NOT get reliable feedback on most of these "high performance" parts. This simply happnes because most of these cars won't get but a couple thousand miles put on them in the next 5-10 years.

When it comes to roller rocker arms the ONLY ones to date I've not had issues with where Crower Enduro, Crane Gold Race and Harland Sharp. For all the others we've put in service they either cracked, broke, or burnt up the needle bearing or roller end of them.

I see the SAME issues with other parts commonly used in these engines and have responded accordingly. I completley quit using "double roller" timing sets for the same reason. ALL of them failed or get WAY too loose for my liking, and some in pretty short order. I know, I know, about the time you tell someone that your Rollmaster timing set failed in a couple of years in your 455 a dozen folks come on and tell you they have 250,000 miles on one and it's tight as a banjo string.......FWIW.......

Had a 70 SS 454 Chevelle come in about a year ago with the "blue death" Scorpion rocker arms . 11 or 16 cracked just like that. Unfortunately, 1 of the 16 had the pin come all the way out and it dropped a valve. Amazingly, it just beat the hell out of the head and dinged up the piston and nicked-up the cylinder a little. Was able to save the head by replacing 2 seats and some grinding/clean-up on the rest. It was a hydraulic roller engine. 150 lbs. on the seat, nothing crazy. I will not guarantee any stud mounted aluminum rocker arm for this reason. The replacements on this engine were Crower stainless steel. Cracked like Cliff's pics is VERY common across the line for aluminum rockers of this general shape and design. Probably Harlan Sharp, made in Ohio, would be the best of this general design. Even if I was using them, I would pop the valve covers off every year and take a peek.