Raising the performance level of an engine can often set off a domino-effect chain of requisite upgrades to support the changes that have been made. An engine’s valvetrain is a prime example, as camshaft profiles are made more aggressive, in turn requiring heavier valve springs to maintain control of the valves at high RPM, which then increases the loads placed on the rocker arms and associated parts. With traditional engines, it’s generally a matter of selecting the right upgrades from a catalog, but with some of the new generation V-8s, those parts simply don’t exist.
Fortunately, progressive engine builders have led the charge to develop competition-level hardware for today’s engines, Livernois Motorsports among them. Livernois’ work with Chrysler’s contemporary Hemi engines, the 5.7 and 6.1, led to the realization that the factory’s rocker shafts were simply not strong enough for competition-level combinations, which caused flexing of the shafts under load. Consulting with the valvetrain specialists at Trend Performance led to the development of new Hemi rocker shafts, produced by Trend using thick-wall 4130 chrome-molybdenum, which are through-hardened and nitrided before receiving a diamond-like coating (DLC). The resulting shafts are not only durable, but the surface is also highly wear-resistant.
The Trend rocker shafts are produced to directly replace the Chrysler shafts, with all of the required mounting and oiling holes, and are available from Livernois Motorsports.