Adjusting new hydraulic lifters 92 5.7

[geolee]

I put a new cam and lifters in and first time adjusting them. Can you guys give me some advice on how you do it? I haven't ever put a new cam in and don't want to ruin it. Thanks in advance

 

[1987 GMC Jimmy]

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Make sure you’ve got the assembly lube liberally slathered on there!

 

[geolee]

Thanks for the reply I just wanted to see how everyone does there's

 

[Salty Crusty]

^ rotating 360* as the video suggests puts you right back where you started. If you started at TDC, rotate 90* and adjust the loose ones, then 90* more, etc. until you're all the way around with the full 360 TWICE (since the cam turns at half the speed of the crank, it takes two full turns to cycle every cylinder)
Whatever method you use, made sure you're only adjusting the ones where the valve is closed. I know it sounds like a no-brainer, but I've seen people adjust everything in one spot and then not understand why it doesn't work.
DON'T use the "spinning the pushrod" method, I've seen pushrods that would still spin freely with the valve halfway open. This guy's method of using up-and-down is much better.

 

[broketiredugly]

if you soaked the lifters in oil first, be sure and tighten the nuts slowly to allow bleed off. and never just fire the engine up after adjusting the valves, let it sit for 10 or 12 beers.

 

[chengny]

Before you begin the valve lash (actually it's called the pre-loading) process, there are a couple of things worth mentioning:

Before you begin, it is vital that any lifter pre-load that you may previously applied is completely released. Since both your cam and lifters are new, it doesn't sound as if this will apply to you. Work around the engine and back off all the rocker adjusting nuts. Allow some time for the plunger springs to drive the plungers to the very top of their strokes. The socket ( the cup that the pushrod rides in) of a fully decompressed hydraulic valve lifter will be hard up against the bottom of the circlip. See the images below.

Also, be aware that this process is a one shot deal. By that I mean; once the spring is compressed - whatever you use, 1/2 or 3/4 turns past zero lash - you cannot go back around the rocker nuts and .... let's say - "check your work". That is, unless you start all over again by releasing any applied preload.

However, before you close everything up and start the engine, there are a couple of things you can check to verify that you have properly preloaded the lifters:

With the lifter off-stroke (i.e on the heel of the cam), check the gap between the socket and the bottom of the circlip. When it was unloaded, the gap should have been zero. Now, with the proper pre-load applied, the gap should be virtually identical to the cross-sectional diameter of the circlip. I don't know whether this is by design - or just a lucky co-incidence - but it is a valid check of proper pre-load/valve lash on a GM hydraulic lifter. See the second image below.

A second quick check is to apply pressure to the pushrod side of the rocker (again with the lifter off-stroke). The socket and plunger should move downward easily (the plunger springs are tiny and weak). The distance you can depress the plunger should be the same as the gap between the socket and circlip. IOW the proper preload will position the plunger at exactly the mid-point of it's total possible stroke.

Unloaded lifter:

You must be registered for see images attach

h

Preloaded lifter:

You must be registered for see images attach

Point is, when you are all done preloading you can easily check your work by rotating the engine. As each piston reaches TDC on compression, look down into the top of the lifter and observe the circlip/socket gap. If it is about the same as the thickness of the circlip you are good to go.

 

[geolee]

if you soaked the lifters in oil first, be sure and tighten the nuts slowly to allow bleed off. and never just fire the engine up after adjusting the valves, let it sit for 10 or 12 beers.

so your saying let them sit for about a hour? lol

 

[geolee]

Thanks for the replies everyone!

 

[geolee]

Before you begin the valve lash (actually it's called the pre-loading) process, there are a couple of things worth mentioning:

Before you begin, it is vital that any lifter pre-load that you may previously applied is completely released. Since both your cam and lifters are new, it doesn't sound as if this will apply to you. Work around the engine and back off all the rocker adjusting nuts. Allow some time for the plunger springs to drive the plungers to the very top of their strokes. The socket ( the cup that the pushrod rides in) of a fully decompressed hydraulic valve lifter will be hard up against the bottom of the circlip. See the images below.

Also, be aware that this process is a one shot deal. By that I mean; once the spring is compressed - whatever you use, 1/2 or 3/4 turns past zero lash - you cannot go back around the rocker nuts and .... let's say - "check your work". That is, unless you start all over again by releasing any applied preload.

However, before you close everything up and start the engine, there are a couple of things you can check to verify that you have properly preloaded the lifters:

With the lifter off-stroke (i.e on the heel of the cam), check the gap between the socket and the bottom of the circlip. When it was unloaded, the gap should have been zero. Now, with the proper pre-load applied, the gap should be virtually identical to the cross-sectional diameter of the circlip. I don't know whether this is by design - or just a lucky co-incidence - but it is a valid check of proper pre-load/valve lash on a GM hydraulic lifter. See the second image below.

A second quick check is to apply pressure to the pushrod side of the rocker (again with the lifter off-stroke). The socket and plunger should move downward easily (the plunger springs are tiny and weak). The distance you can depress the plunger should be the same as the gap between the socket and circlip. IOW the proper preload will position the plunger at exactly the mid-point of it's total possible stroke.

Unloaded lifter:

You must be registered for see images attach

h

Preloaded lifter:

You must be registered for see images attach

Point is, when you are all done preloading you can easily check your work by rotating the engine. As each piston reaches TDC on compression, look down into the top of the lifter and observe the circlip/socket gap. If it is about the same as the thickness of the circlip you are good to go.

I have seen many different ways everyone adjust them but this pic and explanation helps a lot thanks man!

 

[Rusty Nail]

Before you begin the valve lash (actually it's called the pre-loading) process, there are a couple of things worth mentioning:

you are good to go.

Everything this cat ^^^ says about square body trucks is gold and getting him to reply is a blessing.
If you do what he suggests, it will be correct and you can quit wondering about it.

Hope this helps and good luck!