The most accurate valve adjustment method is called the "companion cylinder" method. It's done with the engine stopped, with two cylinders at the top of the stroke (top dead center). #1 and #6 come to the top at the same time, ditto #2 and #5, and #3 and #4. The firing order is 1-5-3-6-2-4, so the simple way to identify "companion" cylinders is to cut the firing order in half, like so:
1-5-3
6-2-4
The cylinders above each other reach TDC at the same time, one on compression (both valves closed), and the other on exhaust, (intake opening, exhaust closing). Turn the engine by hand and watch the #6 valves. Get them "rocking" exhaust closing, and intake opening, and adjust the #1 valves to specification. Rock #2, adjust #5. Rock #4, adjust #3. Continue down the firing order until all cylinders are adjusted. Warm the engine up, and recheck the clearances. If you adjust the valves about .002" looser than the "hot" specifications with the engine cold, the hot clearance should be about right. Confused yet?
Jerry
