One answer to a question nearly everyone asks is, yes, even though T&D shaft-mount rocker arms are almost always “bolt-on,” the proper roller tip to valve relationship is critical. A little time and effort during assembly will reap huge benefits. In most cases, included shims will be adequate to reach proper alignment. T&D also builds custom height stands – many variations are on the shelf for immediate delivery. In extreme cases, machining the mounting pads on the cylinder head may be necessary. Never under any circumstances machine the mounting stands, grind reliefs into the rocker bodies, or modify the stands or rockers in any other ways.
Each rocker assembly is shipped with an instruction sheet that details just how to achieve optimum interaction between the roller tip of the rocker arm and the valve stem. We suggest that you familiarize yourself with that instruction sheet. If you cannot understand the basic instructions, please call or email our technical department.
In every T&D rocker set is a small tool called a Stand Height Gage. When used per instructions, the stand height gage is invaluable for getting your rocker arms into their proper configuration. T&D also has available Pushrod Length Checkers. After the rockers are placed properly, you’ll need an accurate measurement to enable you to order correct length pushrods.
And, T&D also offers specialized tools to make your job of maintaining your valvetrain a breeze.
Once again, the instruction sheet is your best friend, so refer to it often.
Place the pushrod length checker into a lifter and install a rocker arm assembly. Be sure the cam is rotated to the base circle. Seat the bottom of the adjuster screw up against the recess in the rocker arm and turn the adjuster screw clockwise one full turn down. This is the initial adjuster position. Adjust the pushrod length checker tool to the proper length, remove from the engine, and measure its overall length.
Yes, most T&D rocker bodies (except SportComp) have oil passages that enable engine oil to constantly pressurize the trunion bearings and the rocker tips. This feature gives a longevity factor to T&D rockers that the competition does not provide. It also cools the bearings and shafts. There is also an orifice in the adjuster screw that maintains oil to the interface between adjuster cup and pushrod end. This part of the oil passage must remain open and precautions must be taken to maintain adjuster position (another reason that pushrod length is critical). The rocker arm should not be operated with the adjuster screw more than one turn up or down, from the initial adjuster position. Doing so will cut off the flow of oil to the rocker arm.
We never recommend turning the adjuster more than 2-1/2 turns down. Pushrod length is determined by the following: (1) Turn the adjuster all the way up into the recess in the rocker body until it stops. (2) Turn the adjuster down one full rotation. (3) This is the initial adjuster position. (4) Once the engine is fully assembled, this will be the starting position where lash will be set, and the adjuster should NEVER be turned one full turn either up or down. For general information, the hole in the adjuster that feeds oil to the pushrod cup shuts off flow completely when the adjuster goes just past two turns down from the initial adjuster position.
T&D Machine Products recommends that you choose the highest quality pushrods available for every application, and several manufacturers can provide them.
Included in most rocker sets is 0.090” of shim. That is the maximum we recommend. T&D offers custom stands with extra height starting with +0.100” so it is very simple to get more height if necessary.
Most of the basic instruction sheets can be found on this website. There may not be one for your exact assembly or part number, but similar engine types can use a generic instruction sheet (i.e. most big block Chevys assemble exactly the same).
Every effort is made to include all necessary components for each rocker arm set.
Please check the instruction sheet for your particular application for the torque specifications.