First, determine whether or not the pushrod at the noisy valve is moving up and down the same distance as the rest. One reason for excessive valve noise is a worn-out camshaft lobe. This doesn't have to be a precision measurement, but if there's a noticeable difference in pushrod travel there's no point in attempting an adjustment.
OK, no noticeable cam wear- - - - -on to the adjustment procedure. The firing order is 1-5-3-6-2-4. Cut it in half, and put the first half over the last:
1 5 3
6 2 4
The nunbers aligned vertically are "companion cylinders"; the pistons come to the top of the stroke at the same time, but they're one turn out of phase for valve operation purposes. When #1 is at the top of the compression stroke, #6 is topped out at the end of the exhaust stroke, getting ready for intake. This is the key to a good valve adjustment. Get the exhaust valve closing, and the intake on the same cylinder opening, and the companion cylinder is in the right position for a valve adjustment.
Turn the engine over clockwise from the front by hand (or with a socket on the crankshaft nut) and watch the #6 cylinder valves. The exhaust valve will open, then begin closing, and the intake will start to open. This positionis called "rocking" with both valves open about the same distance. Go to the companion cylinder (#1) and loosen both adjusting nuts several turns to let the lifter go to its fully-extended position. Tighten the adjusting nut until the slack is just barely taken out, then turn the nut another 3/4 turn clockwise. Do the same thing on the other valve for #1. Turn the engine 1/3 turn, and the #2 cylinder valves will rock, and #5 will be ready to adjust. Follow along in sequence, rock 4, adjust 3, rock 1, adjust 6, etc. You can adjust all the valves in two turns of the engine, with no mess from splashed oil. The same procedure works with the engine hot or cold. Good luck!
Jerry
