I know this subject has many opinions. I using the 1 intake at full lift adjust 6 intake. First question while adjusting the valve and once you feel resistance and tightening the nut 1/2 turn should you be able to turn the push rod or should be tight? Second while adjusting the valve why do some push rods have some resistance while others bind up with little turn of the wrench?
I can only tell you my own experience. I am sure there will be many variations and personal preferences. This was done on a few SBC engines with original stamped rockers I would turn over engine by hand until both valves were closed, ratchet down nut until the pushrod stopped moving up and down but still spun between my fingers. I then turned ratchet 1/4 turn. This has worked for me every time. Good luck
Do some internet searching , pick the method(s) that are repeated the most , you'll get varying opinions anywhere , you have to choose , I like comps EOIC but I'm running a " long duration " cam...YMMV
^^^^^ To add. Always keep in mind what it is your working on. Stock very mild lift cams behave different than aftermarket cams with higher lift and duration's. Therefore there is no one work solid one way to do adjustment and or number of 1/4 turn lash increments to use to cover all hydraulic cam profiles.
You’ll still be able to turn the pushrod. The spring in the lifter isn’t that strong. Sent from my iPad using The H.A.M.B. mobile app
Here goes, now mind you I'm anal and forgetful at the same time so I don't use if the if this open then do that valve approach. I do each valve one by one looking for max lift then turning crank shaft one full revolution (cam turns only 1/2 a revolution). That way no matter what cam it is it's always fully on the back side of the lobe. Number of 1/4 turns? 4 or 1 full turn of rocker nut like factory calls for if, ! your not going to rev the snot out of it. This is why guys opt. to use only 1/2 or even only 1/4 turn of adjustment.
And the resistance varies with how full of oil the lifter is. I always start with number 1, TDC, firing position. Then I wiggle the rocker arm up and down as I tighten the nut, and stop when the "loose clatter" stops. The pushrod is still able to turn but it's at zero lash. I do the same to the other #1 rocker. Then I turn the crank 1/4 turn, and move to the next pair in the firing order, set them to zero. Repeat till they're all at zero. Then from front to back on each side, I turn them all an additional half turn (or 1/4 turn or full turn or whatever your magic number is). since I only ever have to do this when I'm putting an engine back together, I also turn the crank an additional quarter turn to get back to #1 firing, and set the timing where it should be (ie. 8 degrees advanced). Then I am ready to drop in the distributor pointed to number 1, and set it so the points just open, or the reluctor wheel just pulls.
Over the years varnish gets in the lifter plungers. I learned 1-1/2 turns for stock engines with new or cleaned out lifters. If you’ve ever had one apart you know what they look like after years of service and having the plunger turn into that “s—t will make them almost solid and hold a valve open. You need to know your engine.
I've just been through this with the 327 in my Corvette. Cold and not running is fine. It takes a little practice to find zero lash from spinning the pushrods, but it is an easily learned skill. If the engine has a mild cam, you can do it in two steps (#1 at TDC and #6 at TDC), but if you have any kind of a hot cam, do it in four steps to be sure. After I got them to zero lash, another 3/4 turn got them where they should be. Setting them while the engine running is real messy no matter what you do, and unnecessary. Because of the configuration of my engine compartment and the accessories (power steering, etc.), it is quite difficult to get in there and turn the crank, which is why I did it the way that requires only two turns. (get #1 to TDC and set 8 valves and turn it to #6 TDC and set the other 8). If it's easy to get at the crankshaft bolt, doing it one at a time (EOIC) is probably better. Here's my thread : https://www.jalopyjournal.com/forum/threads/adjusting-sbc-valves-cold.1203125/.
I'd never use 1.5 turns preload for any SBC engine. I've done this and found some lifters wont allow any oil to get to the rockers if they're that tight. Plus you lose tons of lift and power going that tight. Comp recommended the 1.5 turns on my Comp 280XE and the engine wouldn't accelerate over about 2,000 rpm's. I pulled the valve covers and started the engine, and immediately noticed zero oiling! I freaked out as I thought I'd lost my oil pump, but pressure was 50 psi. I began backing off lash and oil started flowing. When I readjusted the lifter lash to 1/4 turn preload the engine ran 500 rpm's higher! I adjust lifters by first removing the spark plugs. This makes the engine easy to turnover. Then I pick a cylinder, and don't care which one it is. I watch for an intake or exhaust valve to begin to open, and then I set the opposite valve lash. Turn it again to see the other valve begin to open, and do that opposite valve lash. I just move through all 8 cylinders until they're done. Then go through and add the 1/4 turn and I'm done. May be faster ways of doing #1 and #6 at the same time, but I like my method, and it's worked for 50 years.
On my hyd roller I start at no. 1 tdc and turn the crank a 1/4 turn at a time and follow the firing order. On a flat tappet hyd, I turn the nut down until the push rod quits spinning with my fingers and then add a 1/8 to a 1/4 of a turn. If i'm doing it right after I build a engine I leave the primer in the dist hole and spin it on every cyl I adjust to make sure the lifters stay pumped up good.
I like to do it hot and running method. Have an old valve cover that I cut the top intake side and down the sides, and bent the top up vertical to catch the oil. Start engine and go through each cylinder loosen until it clacks, then slowly turn down until no clacking, then set 1/4 or 1/2 turn. I like this method since it sets each valve lifter at the same point. Doing it cold, with some variance in the lifter clearances, it is not as exactly the same. Does it make a real difference? Probably not, but I just like the hot and running method as it seems to make the engine run real nice and smooth.
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