Where do the valves go in an overhead cam engine?
The valves come into the checking position in a jumbled order – do not mix up inlet and exhaust clearances. On some old overhead-cam engines you can adjust the shims to a limited extent by screwing up a wedge over them, through a small hole.
How do you adjust a 235 / 261 valve?
NOTE: If your 235/261 is equipped with hydraulic lifters, the adjustment procedure is the same, except you carefully adjust each valve to zero lash when it is in position, then give the adjusting screw 1/4 turn more and lock the nut.
How do you adjust the intake valve lash?
When all of the intake valves have been set to the proper valve lash, you can adjust the exhaust valves. Utilizing the same procedure as with the intake valves, you need to turn the engine over until the intake pushrod moves all the way up and rotates just past maximum lift.
How do you check the valves on a 4 cylinder car?
For example, on a four-cylinder engine when the rockers on No. 1 are rocking you can check both valves on No. 4. Turn the engine in its normal direction of rotation by using a spanner or socket wrench on the crankshaft-pulley bolt until the two chosen rockers rock. Leave the feeler gauge in place whilst you adjust.
How to adjust the valves on a single overhead cam engine?
Thus, on an internal-cam engine, put a wrench on the crankshaft pulley and rotate it to line up #1 cylinder to TDC, adjust the valves for that cylinder, then rotate the engine 180 degrees in its normal direction of rotation and adjust the valves for the next cylinder in the firing order. And what is the “normal direction of rotation?”
When does a cam line up with the crankshaft?
When a cam is installed “straight-up,” the imaginary centerlines of the two shafts line up exactly. Advancing or retarding the cam pushes the centerline of the camshaft to one side or the other of the crankshaft centerline.
How does advancing or retarding a camshaft work?
Advancing or retarding the cam pushes the centerline of the camshaft to one side or the other of the crankshaft centerline. This changes the Timing of the valve opening and closing events, in relation to the position of the piston in the cylinder. How is it measured? Find the lobe centerline in relation to the piston’s position in the cylinder.
NOTE: If your 235/261 is equipped with hydraulic lifters, the adjustment procedure is the same, except you carefully adjust each valve to zero lash when it is in position, then give the adjusting screw 1/4 turn more and lock the nut.