CTCI Authenticity Chairman
PHOTO 1 – Insure the dial indicator plunger is free. It must move freely in and out. The plunger is spring loaded out. Some units have been idle and stuck in position, lubrication may be required to free the plunger. The unit should be clean and lubricated.
PHOTO 2 – Engine should be brought up to normal operating temperature. Adjustment can start on any valve. I usually start on number one cylinder and work through all eight cylinders. Use a remote started switch to close the valves on number one cylinder this creates a gap between the rocker arm face and the top on the valve stem. When using the remote starter switch insure the ignition switch is off and the coil wire removed. Insert the P&G gapper with proper inner barrel. Barrel number 111 1B is correct for a 272/292/312 Ford engine. The number is on the inner barrel on the top edge. Once attached under the rocker arm the top of the valve stem is visible through the opening in the lower barrel. The gapper rest on top of the valve spring retainer and is held in place by the rocker arm. Rotate the thumb screw up until it just touches the dial indicator plunger. Rotate the dial face until the needle points to 0, next use the thumb screw below the dial indicator plunger to move the needle past desired valve gap. If the desired gap is .019 then move the needle to .025 slightly more or less.
PHOTO 3 – Set the dial face to 0. Using the remote started switch to turn the engine you will observe the needle move from 0 to the number that represents the gap of the valve lash. After a few revolutions of the engine the O setting may move and it can be reset or you may use the value of the numbers the needle bounce between to determine the gap. Example 0 – 19 would be .019 or 10 -29 would also be .019. After you play with it a few times using the remote starter switch you will understand how it works. The gapper is designed for use with the engine running at idle do not accelerate the engine above idle. High engine rpms causes the needle to oscillate too fast which could led to the needle separating from its shaft.
PHOTO 4 – When starting the engine with the gapper in place insure the carburetor is not on fast idle. When engine is running at idle the needle oscillates between open and close position of the rocker arm to stem giving an accurate reading of the valve lash. The valve rocker gap can be adjusted to the desired gap with the engine running at 650 rpm or slightly less. With the engine running rotate the dial face to line up with the needle pointing to 0, as the needle point oscillates to the other end of travel observe the number, that will be the valve gap. Needle movement between the numbers is quick and takes practice to properly read.