The "rule of nine" implies that you add 1 to the number of valves - the engine has 8 valves, thus adding one reads nine. When valve #1 is fully open, you check and adjust #8 (1+8=9). You will have to turn the engine around a lot if you work your way through the valves one by one from #1 to #8. To simplify the process, the table below shows the order which will require the least amount of turning the crankshaft:
Valve fully open | Check and adjust |
Valve #1 | Valve #8 |
Valve #3 | Valve #6 |
Valve #5 | Valve #4 |
Valve #2 | Valve #7 |
Valve #8 | Valve #1 |
Valve #6 | Valve #3 |
Valve #4 | Valve #5 |
Valve #7 | Valve #2 |