View Single Post
Jim Williams Jim Williams is offline
Registered User
Jim Williams's Avatar
Join Date: Feb 2005
Location: Huntsville, AL
Posts: 1,346

I've never seen any tolerances on wear of the rocker arm faces. You're right, obviously all these working parts need to be parallel, rocker bores with respect to the faces that ride on the cam, and of course, the surfaces of the lobes on the cam with respect to the centerline of the cam.

But I don't know how you would measure any of this parallelism with the tools available to the average mechanic. I think about all you can do to inspect the faces of the rockers and make a judgment that there are no ridges or pits present. I don't find anything in the spec books with any tolerances on this. I guess one has to pretty much trust the machine shop to hone the rocker bores to be parallel with the rocker faces.

If you are going to disassemble the parts in the cam housing with the intent of putting it all back together, it is reconmmended that the rockers be bagged with the location written on the bag, then the rockers returned to the original position. I think this is just considered to be good engine rebuild practice. if you happened to be putting in different cams, then I'm not sure why this would be required.

Maybe someone else will have a different take on this.
(CIS Primer for the 911)
(73 911T (RS look) coupe)
(Misc. 911 Parts for Sale)
Old 04-21-2005, 05:01 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)