Technical Information (MGB 16A)

Harland Sharp Roller Rockers and Tubular Pushrod Information

Last Updated 2/28/07

I would like to bring to your attention the following important items:

1. Over and above what we have outlined in technical article MGB16, we would like to point out that it is imperative that the aluminum spacer(s) be installed. If the spacer installation is ignored, you will find that over a period of time the rocker arm hardened steel roller will wear into the aluminum side supports. We feel that since you have invested a considerable amount of time and money in your engine rebuild project, you should spend a little extra time in the rocker assembly procedure.



2. If you are installing the roller rockers, in conjunction with 5/16" tubular pushrods, it is important that the pushrod cup is not contacting the underside of the rocker, especially at full valve lift. Contact usually occurs if the rocker arm adjusting screw is screwed too far out leaving very little of the adjusting screw underneath for pushrod cup articulation. Therefore, to prevent this contact, there must be adequate adjusting screw thread protruding from beneath the rocker arm. See image P0003460 below.

NOTE: Our custom made Harland Sharp roller rockers, manufactured by Custom Speed Parts, now have this particular area of the roller rocker extrusion enlarged to prevent contact. However, it is still advisable to heed the warning given.

If you are having this problem, the rectification would be to install shorter pushrods, Unfortunately, this problem is not usually discovered until final engine assembly, which usually means that you have already purchased your 5/16” tubular pushrods. To this end Moss Motors supplies slightly shorter than stock versions under part number 460-616, and are sold separately. Be reminded these pushrods require the fitting of 18V type shorter lifters.

However, on the other side of the spectrum, if you are having trouble with running out of adjusting threads, longer adjusting screws are available thru Mini-Mania under part number CAEA692. Phone contact: (530) 470-8300.