How exactly do you adjust the valves on a engine? I must do it on my engine after finishing a cam swap. I have heard many ways such as spin the pushrod until you feel a slight resistance and then turn it 3/4 of a turn, or spin the pushrod until you cant spin it anymore and then tighten it 1/4 of a turn. I know that you have to get the engine on top dead center and have the lifters on the heel of the cam and all that first, but how exactly do you do the adjusting after that point?

 

Not TDC.

Use the EOIC method. That stands for Exhaust Opening, Intake Closing. You adjust a cylinder's intake valve just as the exhasut starts to open, and adjust its exhaust as its intake is just closing.

Put all the push rods in, and put all the rockers on, and tighten them until there's about 2 threads showing on each stud. Then, using a crank turning tool, turn the crank until you see the #2 exhaust push rod raise up, and then drop back down. As it starts to drop back down, you'll notice the #1 exhaust push rod coming up. Hold your finger gently on the #1 exhaust push rod while turning the motor, and when it stops moving down, adjust the #1 intake. It will be floppy loose when you start of course. If you push it down hard into the lifter, you'll probably be able to feel the little spring in the lifter being depressed. Tighten the rocker nut just until it takes up all the slack, and starts to depress that spring. You can wiggle the push rod up and down as you tighten, and feel the really loose slack go away; when it is all gone, you are at zero lash. Tighten it ½ turn more. Turn the crank exactly 90°, and do the next one in the firing order (#8). Then 90° more and do #4, and so on, through all 8 intakes. Then do the same thing of turning the engine while watching the #1 intake valve, except this time, watch for it to just barely begin to move; and adjust the #1 exhaust rocker as you did the intakes. Turn the motor and run through all 8 exhausts.

That'll get it plenty close enough to run. THen once it's running, you can re-do them that way, if you want; back each one off until it just begins to clatter, tighten it back until it just quits. Do all 16 like that. Shut the motor off, and tighten all 16 an additional ½ turn.

 

How much you turn in after achieving zero lash depends on the cam. Follow the cam manufacturers instructions.

 

I do mine one cylinder at a time because I have a degreed balancer and a remote start button mounted under the hood but can also adjust them in 2 rotations of the crank using the timing mark on the balancer.

With the timing mark at zero, #1 and #6 pistons will be at the top of the cylinder. One will be on exhaust stroke, the other will be on compression stroke. You'll have to look at the rockers or the distributor rotor to determine which cylinder is on the compression stroke. Using this procedure, the valve being adjusted will always be on the base circle of the cam.

When #1 is at TDC compression, adjust
INT 1, 2, 5, 7
EXH 1, 3, 4, 8

When #6 is at TDC compression, adjust
INT 3, 4, 6, 8
EXH 2, 5, 6, 7

Hydraulic lifters need to be adjusted a specific way. Loosen them off and let them sit for about a minute to allow the lifter plunger to retract. Then wiggle the pushrod as you tighten the rocker. I don't like the "spin the pushrod" method. Wiggling it can still determine that there's no play in the pushrod and if it's too tight, it won't wiggle but can still spin. As soon as you can't wiggle the pushrod any more, you're at zero lash or close enough to it. Tighten the rocker 1/2 turn more from zero lash and move to the next one. The lifter will bleed down and the pushrod will feel loose again. Don't tighten it any more thinking it's loose. That 1/2 turn sets a .030" preload inside the lifter. Overtightening too much will damage the lifter or wipe out a cam lobe or cause any number of valve train problems.

With solid lifters, you adjust them in the same procedure except you use a feeler gauge to measure. Also with solid lifters and using aluminum heads, you can decrease the gap .006" to allow for expansion. Hydraulic lifters will automatically compensate to allow for expansion with aluminum heads.

 

running a 1/4 turn can break the retaining ring in lifter and send it to the oil pump at 5000 rpm.

AMHIK

 

 

No, only until all of the lash (vertical movement) has been taken up.

Use a feeler gauge for consistency.

If you set them properly, you can use as little as an 1/8th turn and not
hurt anything.

You'd all freak if you knew what little pre-load was used on race hydraulic
flat tappets.

Some of the method listed here are only good for stock cams. Once you
get into small base circle stuff with huge durations, the baseline method
is the only way to ensure the lifter is not on a closing, or opening ramp.

The Ex./In method is pretty too.

 

Hi per/racer lifter okay but not with a NAPA lifter with a .5 lift RV cam.

Put cam/lifters in 427 BB engine. Way later when oil was cold something sucked into oil pump. Broke oil pump shaft and the plastic collar that aligns the oil pump shaft to extention to run dizzy. Grooved oil pump gears.

Replaced oil pump and extension shaft. This time with steel collar.

When engine torn down for refresh 50,000 miles later, #8 lifter retainer was missing, figuared it went into oil pan, and went through pump.

Other half of retaining ring had left nice big groove around the oil pump gears again. Engine ran for the 50,000 miles with no indication of what had happened. Refreshed motor to put in an other vehicle. Was running fine.

Probably over reved the motor (5000 rpm).

1/4 turn worse than no turn.

 

It's been done on $30.00 Fed. M.'s hydraulics without failure. I've set mine to
0.005" with a dial and run the motor to 6200 RPM. That was a 0.320" lobe and
0.517" at the valve.

You just have to be sure there is a certain amount of pre-load and the
springs are capable of limiting float.

I don't recommend going that close on a daily street motor; it's just not
needed.

 

Better to use 1/2 turn or your, just past tight, .005 preload.

That .005 allows lifter to run pumped up all the time just like a solid but no noise.

mine were set at 1/4 turn with stock tired springs.

 

Ever seen a situation where at least half of the plungers won't depress? Half of my valves, when I adjust them will open the valve before it preloads the plunger.. I don't know if it will "cure itself" on startup. It's been sitting since September.

If my new comp lifters are junk, I'm going to flip out.

-- Joe

 

That is likely because the oil inside the lifter has not bled down.

If you rotate the engine by hand a couple of times, the spring pressure will
force the oil out of the lifter.

The lifters that feel solid are likely on cylinders that are on the compression,
or power stroke position and have little to no spring pressure on the lifter
seat.

 

Maybe once I fire it it will be fine then. I rotated it a few times to do a cold valve adjustment. Just noticed it was weird some of them were solid. They were each @ TDC compression stroke when I adjusted them. 1/4 turn past lash. Didn't bother checking any during valve lift for solidness. Oh well.

Thanks

-- Joe