TECH-LINE

TWISTED ROCKERS

The Illustration to the left shows two views. The rocker arm has a stud that is .142" offset from the valve, and on this example length, it creates about 5 degrees of rotation. Some heads may be less, some more. But the point is, there is little room for any misalignment that doesn't still show the same symptom of damage and misalignment of the roller upon the valve. The valve spring to the right illustrates the STUD Axis of leaning into the valve 11 degrees. CLICK FOR PHOTO CLICK Illustration for COMPOUND GEOMETRY.

Whenever a rocker arm is ROTATED on the stud of a head that has IN-LINE valves (as viewed from the end of the head), this is the effect that is created. There's no other way around it. Yet, to this day, countless heads are sold with offset pushrods, and WORSE, offset studs that FORCE the engine builder to "presume" this is for a proper design reason, when in fact it is GROSSLY bad engineering, or bad judgment. Any heads that have studs with a compromised offset from what the pushrod is, induces false trust to the engine builder that a stud mounted rocker will operate properly as long as the three points are connected: PUSHROD, STUD and VALVE. Not so! You will need STUD rockers that have a designed offset in the roller and pushrod cup, to use with such heads. OR... you will need STAND mounted rockers (also known as "shaft" rockers). (ABBREVIATED)

The above budget brand rockers even have an offset pushrod which should have minimized the above "twist" to aid a very bad head design, but to no avail. In spite of this, these aftermarket heads have such misaligning STUD placement for the pushrod offset, that this TWIST is the BEST result that could be obtained. This is a great example of what NOT to do!  ^