You would have been compressing the spring even with oil in the lifer, because after you passed zero lash, you forced the oil out of the lifter. Play, is lash. Where the play JUST disappears, is zero lash. Any depression of the plunger is "preload". When the plunger is forced all the way to the bottom of the lifter and is stacked solid, all the preload is used up and the valve is forced off the valve seat. Because the valve can't close in this condition, there is no compression and the engine won't run.

RACE ON!!!

 

Just make the adjustment with the car running - just loosen until you hear it clack, then 1/2 turn

 

Got it. Thanks.

Right now I'm just using the measuring rods to get the right size.

I will order the push rods tomorrow once I know how big it needs to be.

Zero lash needs to be set BEFORE the spring is compressed.

 

These guys are right on the money with the zero lash tip stuff....I only give it a 1/4 turn for the preload myself and have never had a problem. If you get too much preload on them you know right away 'cause the engine will pop and bang something fierce when you crank it.

On a side note.....depending on the style of rocker arms you run.....if you replace the pushrods it may not be a bad idea to swap the rockers out too.

 

New rockers, new pushrods, the only thing I re used was the lifters. The car only has 30K miles. I'm measuring the pushrod length right now, so I can order them today.

 

No! No! No! Zero lash IS before the (plunger spring you can't see) becomes compressed. Maybe we have to do this again.

When the push rod jiggles up and down, you have play. You have lash. You don't "set" zero lash. You remove lash until it is all gone. You keep reducing the lash (play) until it disappears. You go from .030" lash (play) down to .020" lash, down to .010" lash, and finally down to where the where the lash (play) is .000" ZERO LASH.

When you proceed beyond zero lash, you start to push the lifter plunger down into the the lifter body by compressing the plunger spring, inside of the lifter. You can't see this spring because it is inside the lifter, but if you look closely, you may be able to see the plunger sink lower into the lifter body. The plunger descending into the lifter body is preload. Preload can be measured in thousandths like lash, .030", .020", etc, or it can be expressed as the number of turns (or fractions thereof) of the adjusting nut.

Therefore, it is not that "Zero lash needs to be set BEFORE the spring is compressed.", it is zero lash IS the condition that exists just before the spring starts to be compressed.

RACE ON!!!

 

"OK OK I know that you find ZERO LASH at TDC"

Are you sure you have the cam on the base circle?

 

Here's some basic info that might speed things up for anyone doing a valve adjustment. Turn the engine clockwise until you see #1 cylinder intake valve close. Keep going until you see the timing mark lines up with zero. Now you are at TDC #1. Adjust the following valves; intakes on 1,2,5,7 exhaust 1,3,4,8. turn the engine 360 degrees, now TDC#6. adjust intake 3,4,6,8 exhaust 2,5,6,8.

Have Fun, Paul

 

Thanks, that was the problem. I was rotating the pushrod instead of going up and down.

Once I losened the rocker, and pushed the push rod up and down while tightening the screw by had, there it was. ZERO LASH.

I since the motor had been sitting for some time, I forgot that the lifters would leak down and didn't think that they would compress the spring.

 

The best prcedure is to set Zero Lash, leave the valve cover off on one side. Lay out cardboard under the car and set the lashe with engine running. And the spec for a L98 is one full rotation
Quote from alldata.com

These engines are equipped with hydraulic valve lifters. No adjustment is necessary. However, if valve train is excessively noisy, readjust valves as outlined below.

On some engines, a nylon retainer is used to retain the rocker arm. No provision for adjustment is provided.

INITIAL ADJUSTMENT



Rotate crankshaft until mark on torsional damper aligns with center or ``O'' mark on timing tab, attached to crankcase front cover, and piston of No. 1 cylinder is at top dead center of compression stroke. This may be determined by placing fingers on the valves for No. 1 cylinder as timing mark on damper nears the ``O'' mark on front cover. If valves do not move, engine is in the No. 1 firing position. If valves move, the engine is in the No. 6 firing position and should be rotated an additional revolution.
With valves in No. 1 firing position, adjust exhaust valves 1, 3, 4 and 8, and intake valves 1, 2, 5 and 7 as described in step 3.
Back out adjusting nut until lash is felt at pushrod, then turn adjusting nut inward until all lash is removed. When all lash has been removed, turn adjusting nut in additional one turn. Zero lash can be determined by rotating pushrod while turning and adjusting nut.
Rotate crankshaft one revolution, until pointer ``O'' mark and torsional damper mark are aligned. With engine in this position, adjust exhaust valves 2, 5, 6 and 7 and intake valves 3, 4, 6 and 8.
Install rocker arm covers, then start engine and check idle speed and ignition timing.
READJUSTMENT
The following procedure, performed with the engine running, should be done only in case readjustment is required.



After engine has been warmed up to operating temperature, remove valve cover.
With engine running at idle speed, back off valve rocker arm nut until rocker arm starts to clatter.
Turn rocker arm nut down slowly until the clatter just stops. This is the zero lash position.
Turn nut down 1/4 additional turn and pause 10 seconds until engine runs smoothly. Repeat additional 1/4 turns, pausing 10 seconds each time, until nut has been turned down one turn.

 

Exactly my plans.

 

After having done this with the engine running method, for me it's the way to go. It's really easy.

I had been told it would be messy but at least on my car it didn't get a drop outside the head.

Just don't drop your tools into the running engine.

 

Snap On also sells rocker spring clips that clip on the rocker arm and cover the pushrod oil hole so it wont squirt you and they keep the job clean.

 

Edelbrock Performer Plus Camshaft Installation procedures state that when setting valve lash that you should not pump up the lifters.

 

For an aftermarket cam I prefer to turn the crank by hand, as the exhaust starts to open adjust int., and just before intake closes adjust the exhaust. Then just go straight down the bank 1-3-5-7 etc.

 

To clarify mseven's procedure on the ex. valve adjustment, the engine should be turned until he intake goes fully opened, and just starts to close, then adjust the exhaust. And as he said, turn until the ex. just starts to open, then adjust int. (this procedure is from my engine machinist, not me or conjecture)

Rich K

 

That's how mine lined up and I haven't had any issues.

 

Just got done counting, and there are only 10,001 pages, including this one. (I knew I could prove you wrong eventually!!!!) Of course you have been right more than 10,002 times for me to finally get one on you.

 

Or accidentally slip your fingers between the rockers!!! It is easier to tell 0 lash with a lifter that isn't bled down as spinning the pushrod method works perfectly. CFI is right, that you need to jiggle it up and down if the lifter isn't full of oil. I always stand my lifters up in a jar, then fill the jar with oil (takes more than 1 jar for a V8). I think the lifters stay full of oil that way. New lifters I soak overnight before installation. Right or wrong I don't know, but it works for me. Spin the pushrod and tighten the adjusting nut till I just feel the resistence on the pushrod. Usually it spins easily then all at once stops. I go 3/4 turn for preload.

 

DAMN! I've been proved wrong...AGAIN!

RACE ON!!!