Another Hydraulic Valve Adjusting Question

[Charlie Brown]

I'm in the process of checking / adjusting my hydraulic lifters with adjustable rocker arms. The rocker system I have are Harland Sharp units which are shaft mounted. I have the adjusting chart which is handy. The engine in question is a 426W. It has not run in 5 months, but has 3k miles on the engine. Some people say to spin the push rod until it spins no more and adjust from there (1/2 - 3/4 turn), others recommend eliminating lash (removing the up / down movement) then adjust from there. I've done the spin thing, but it looks like not all the rockers are adjusted the same - i.e. when I push down on the rocker tip, some travel more than others. Does the engine having not run for 5 months have an affect on adjustment? Could some of the lifters be more pumped up than others thus affecting the adjustment? So I'm reaching out to find out which is the preferred / correct starting point - twirl or zero lash.

 

[sw70rr]

I like to move the push rod up and down and gently tighten the adjuster till there is no more movement. I find with the spin technique its possible to start depressing the lifter plunger. Most adjusters are 24 threads per inch. So 1/2 turn gives .021 and 3/4 turn gives .031. I have adjustable roller rockers and use 3/4 turn for .031. My 440 with aluminum heads and flat tappet cam has always seemed happy this way.

I've never had a lifter misbehave. But if you're concerned you could defeat the ignition and crank the engine to build oil pressure to fill the lifters then try setting the preload.

 

[Charlie Brown]

I like to move the push rod up and down and gently tighten the adjuster till there is no more movement. I find with the spin technique its possible to start depressing the lifter plunger. Most adjusters are 24 threads per inch. So 1/2 turn gives .021 and 3/4 turn gives .031. I have adjustable roller rockers and use 3/4 turn for .031. My 440 with aluminum heads and flat tappet cam has always seemed happy this way.

I've never had a lifter misbehave. But if you're concerned you could defeat the ignition and crank the engine to build oil pressure to fill the lifters then try setting the preload.

Good advice, Thanks.

 

[khryslerkid]

It's a fine touch, be one with the pushrod grasshopper!

 

[WS23U1]

Your lifters are probably collapsed. Prime the engine and turn it by hand (have a friend help) to get them to pump up then adjust them. Personally I zero lash them just give them a thou or two. But do it how you like them.

 

[Charlie Brown]

Your lifters are probably collapsed. Prime the engine and turn it by hand (have a friend help) to get them to pump up then adjust them. Personally I zero lash them just give them a thou or two. But do it how you like them.

Just finished adjusting. Before doing so, I cranked the engine over to get full oil pressure using only the starter. I adjusted to zero lash plus 1/2 turn on the adjusters. While adjusting, there were a couple of valves that I could not get that 1/2 turn because I started to compress the spring. Could this be some of the lifters are pumped up more than others?

 

[WS23U1]

If you are opening the valves something isn't right. Are you sure you're on the base circle for that cylinder? If not that you just may have them too tight.

 

[Geoff 2]

Some bad advice here.
Compressing the v/springs when adjusting just means the lifter is pumped up. The lifter may not be pumped up such that the prod cup is contacting the circlip. This is the problem with adjusting pre-load on an engine that has been running...& you cannot see where the prod cup is.
Valve/prod adjustment: when you can push on the prod & feel the spring in the lifter, I would adjust those valves with 2 turns on the adjuster, after all the slack is removed. When you can not feel the lifter spring, it means the lifter is pumped up. Is it pumped up fully, with prod cup touching the circlip? Unless you can see the lifter, you do not know. With these, I would adjust to 1 turn, after all the slack is removed. These lifters have over 0.150" of free movement & they can be adjusted anywhere within that range.

 

[Charlie Brown]

If you are opening the valves something isn't right. Are you sure you're on the base circle for that cylinder? If not that you just may have them too tight.

I am for sure on the base circle. I did all the others without issues.

 

[Charlie Brown]

Some bad advice here.
Compressing the v/springs when adjusting just means the lifter is pumped up. The lifter may not be pumped up such that the prod cup is contacting the circlip. This is the problem with adjusting pre-load on an engine that has been running...& you cannot see where the prod cup is.
Valve/prod adjustment: when you can push on the prod & feel the spring in the lifter, I would adjust those valves with 2 turns on the adjuster, after all the slack is removed. When you can not feel the lifter spring, it means the lifter is pumped up. Is it pumped up fully, with prod cup touching the circlip? Unless you can see the lifter, you do not know. With these, I would adjust to 1 turn, after all the slack is removed. These lifters have over 0.150" of free movement & they can be adjusted anywhere within that range.

A little more clear now, but what confuses me is when I turn the adjuster past 1/2 turn, it pushes on the spring / valve tip and the valve begins to open - in my mind, this is not good.

 

[sw70rr]

This suggests the lifter plunger is not moving freely. The plunger has a lot of travel. At least 1/8 or more. My first thought would be the lifter plunger is collapsed or stuck some where else in it's travel. If you compare the tip height of the pushrod on the bad cylinder to the height of pushrod on a cylinder you are satisfied with, if the lifter is collapsed you may be able to visually see the difference in height.