I'm kind of old school when it comes to adjusting valves. I like to have the lifter in the dead center of the base circle when setting lifter preload. I turn the engine so that the valve that is exactly opposite of the one that I am adjusting is at peak lift.
The easiest way for the first-timer to do that is to take the firing order and write it out like so:
Then, to find the valve exactly opposite of the one you're adjusting, you simply find the cylinder either directly above or below (in your list) the one you're adjusting and put that valve at peak lift.
Example: If you're adjusting the #1 exhaust valve, you look at the list you made and you see that #6 is directly below #1. So you turn the engine so that the #6 exhaust valve is at peak lift. this will put your #1 exhaust lifter in the exact middle of the base circle, where you can properly adjust it.
As far as adjusting them, I use 3/4 turn on a stock rocker (1.5:1) and rocker stud (3/8-24).
EOIC works alright until you have a slippery roller valvetrain with heavier springs, and the bump starter method stops working -- i've found that every time i get it close to where i need it, it'll jog itself backwards or forwards a bit
also it's a shitty method to learn and rely on since you can't start from nothing, it's only good if your rockers are already in place, unless you do something dodgy like watching the pushrods while applying a little pressure to them to hold them in place.
after trying every method a million times, moving each cylinder to top dead center on the compression stroke and adjusting both valves on that cylinder seems to be best.
hell as long as you're even in the ballpark of TDC on the compression stroke, you're good.
if you think about how a 4 cycle engine works, it goes into the compression stroke, the valves close, then it goes into the firing stroke, and the valves must still be closed. that gives you a gigantic amount of base circle to play with for both valves.
Ya know, adjusting the valves is one of the easiest ways to distroy your engine. All lot experienced enthusiests take it for granted and gives the new/never done before owner the wrong impression - its overly easy and the bad results are not realized.
Too little adjustment and the lifter can slap the lobe - bent p-rods, wiped lobes/lifters.
Too much adjustment and the lifter holds the vlv open - broken studs, bent p-rods, burnt valves, backfires.
Either way the vlv train has a shortened life - possibly enough metal loose inside engine to destroy all bearings also.
Important keys here:
-be positive your lifter(s) are on the base circle of cam for the cyl your working on - u need to be certain your on the base circle of cam for the valves/lifters/lobes your adjusting.
-zero lash is when u can still roll the p-rod with your fingers side to side - rocker nut not tight enough to stop p-rod from rolling with just your fingers.
-if u can move the p-rod up or down at all then not at zero lash.
-if u can't roll p-rod with fingers then rock nut to tight.
-don't assume here, this makes irreversable damage once u start the engine if not correctly set.
-take enough time to read up and draw some diagrams if needed until u fully understand the piston order for TDC and lifter position for fully closed and valves in overlap.
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