roller rockers

[Dave Ribeiro]

Ron, you have a PM............

[R. Thorne]

Dave, you have a pm.

[Bill Edgeworth]

I have tried them all.
It’s interesting with the exact same peak lift my Holroyd ones are faster than my Harland-Sharp ones. Just a matter of the geometry of a stamped steel rocker vs. a roller rocker producing a different lift curve. I’ve never broken one of the Holroyd’s or Harland Sharp (knock on wood). I used to break the same punched steel ones all the time before I had Holroyd modify them for me. Only roller rockers I have ever broke were Crane on a big block Mopar. On that after changing to T&D I never had another problem.

[R. Thorne]

Thanks to all who replied here and PM's and to Randy Jr. at HarlandSharp. Bill, did the standard Harland Sharps (s6001) check the same max lift as the oems/Holroyd (ie same ratio or slightly higher) ? Anybody else notice any difference in their max lift after changing to roller rockers?Thanks, Ron.

[Bill Edgeworth]

Originally Posted by R. Thorne

Thanks to all who replied here and PM's and to Randy Jr. at HarlandSharp. Bill, did the standard Harland Sharps (s6001) check the same max lift as the oems/Holroyd (ie same ratio or slightly higher) ? Anybody else notice any difference in their max lift after changing to roller rockers?Thanks, Ron.

Harland Sharp produced higher lift, a shorter pushrod was required. Even the modified punched steel ones still flex.

[R. Thorne]

Thanks, Bill, any particulars (how much more lift and how much shorter pushrods?). Also, were the Harland Sharp rockers the standard ones, diamond series, or HD ones? PM me if you prefer. Thanks, Ron.

[Alan Roehrich]

Comp Cams has a new Ultra Pro Magnum Series chrome moly steel rocker that uses a 1/2"-20 stud, for the big block and small block Chevy. It is the result of some serious efforts by Tim Cole and myself since the roller rocker rule was announced. The new rocker accepts an ARP Pro Series rocker stud that is 1/2"-20 on top as opposed to 7/16"-20, made exclusively for Comp Cams by ARP. The rockers are rebuildable, and the body is guaranteed for life against breakage.

[Bill Edgeworth]

Originally Posted by R. Thorne

Thanks, Bill, any particulars (how much more lift and how much shorter pushrods?). Also, were the Harland Sharp rockers the standard ones, diamond series, or HD ones? PM me if you prefer. Thanks, Ron.

My numbers in relation to your situation are totally irrelevant unless everything was exactly the same including seat pressure/spring combo, same stamped steel rockers, head geometry, deck height etc. I’m not sure that Pontiac made these heads all that accurate; I have a couple different sets of 6x heads that are supposedly prepped identically but require different pushrod lengths. That leads me to believe the rocker stud placement is not all that accurate. So what I can tell you is that in my case they produced 0.007 more lift and took almost 1/10” reduction in pushrod length. The Rockers are just the S6001 that’s all you need with your combo, its low lift and low RPM.