440 Valve Preload Adjustment

[ohitsjustbrian]

Going through valve lash adjustment using exhaust opening intake closing method (EOIC) comp cams recommends about .045" preload and I noticed #4 intake is significantly higher (adjustment screw almost 1.5 turns out further) than the rest. I double checked it a couple of times because I know the lifters are easy to compress, pulled the rocker shaft and checked pushrod length against the others and they are the same. I'm running 440 source 1.6 adjustable rockers, wondering if there's enough slop there to account for the difference which is about .050". Should I be concerned or run it? At the very least I'm going to do a leakdown test after I get her back together hopefully today or tomorrow.

Thanks in advance!

 

[PRHeads]

Is the top of the valve even with the others?

Have you verified the length of the adjuster screw is the same as the others?

If those things are correct, and the pushrod is the same/correct length, I suspect a lifter issue.

 

[RemCharger]

What heads? New, rebuilt..

 

[ohitsjustbrian]

Is the top of the valve even with the others?

Have you verified the length of the adjuster screw is the same as the others?

If those things are correct, and the pushrod is the same/correct length, I suspect a lifter issue.

Forgot to mention this, yes I did measure the adjustment screw, it's the same. I did not measure the top of the valve, do I need to get to shaft off again to measure this or is it enough to get it back on base circle and compare to another closed valve?
What could make a lifter taller?

 

[ohitsjustbrian]

What heads? New, rebuilt..

Edelbrock Performer RPM. It's a relatively new build, Id guess I'm at around 200-300 miles.

 

[PRHeads]

What issue could make a lifter taller?

A problem with the(or broken) snap ring, allowing the plunger to sit higher in the body.

 

[RemCharger]

Are the rockers used? I believe the 440 source ones have the not so desirable needle bearings

 

[padam]

If it’s a non symmetrical cam, the base circles may be different. It confused the hell out of me when I was measuring stuff on mine

 

[ohitsjustbrian]

A problem with the(or broken) snap ring, allowing the plunger to sit higher in the body.

Took this picture recently, piston 4 intake lifter is on the left here on its way up. I think I can see the retainer but I'm not sure. What do you think?

NOTE: Mocha latte oil is from when the drivers side head gasket went and is the reason I was in there.

 

[GTX JOHN]

Probably Lifter issue.

Remove/Inspect that lifter.

 

[PRHeads]

What brand & part number are the lifters?

The reason I ask is because they look to be the ones with the thin spring steel clip as the retainer.

I’ve seen a few instances where those got damaged during some valve float and a pushrod danced around and “stepped on” the retainer.
Then it folded up and popped out of the groove and was floating around on top of the lifter.

One instance was on a Pontiac, where more than 1/2 were like that.
It was still running fine, and was discovered when the valley plate was removed to cure an oil leak.

You might even be able to see it by looking down the pushrod hole, or looking in the distributor hole.

 

[PRHeads]

Try this……

Rockers off that side, rotate engine to where both lifters are on base circle.
Is the one pushrod cup noticeably higher than the other?

 

[ohitsjustbrian]

Try this……

Rockers off that side, rotate engine to where both lifters are on base circle.
Is the one pushrod cup noticeably higher than the other?

They're def within 1/16" (.0625") but there's too much movement and no great reference to measure from so I can't confidently be any more precise than that. Everything up tops alum too so my magnetic base is useless...

 

[GTX JOHN]

What brand & part number are the lifters?

The reason I ask is because they look to be the ones with the thin spring steel clip as the retainer.

I’ve seen a few instances where those got damaged during some valve float and a pushrod danced around and “stepped on” the retainer.
Then it folded up and popped out of the groove and was floating around on top of the lifter.

One instance was on a Pontiac, where more than 1/2 were like that.
It was still running fine, and was discovered when the valley plate was removed to cure an oil leak.

You might even be able to see it by looking down the pushrod hole, or looking in the distributor hole.

I never use the thin wire clips.

Tru Arc makes a clip that slips ring into that groove and
is way stronger.

Usually, I shim some travel out of the lifters as well because my HP applications
do not need near that much travel.

 

[PRHeads]

They're def within 1/16" (.0625")

Is that the same as a pair from a different cylinder?

 

[PRHeads]

I never use the thin wire clips.

I wasn’t referring to the wire clips, I was referring the these, which are designed to preload the plunger some.
In the Hylift-Johnson world, these would be used in lifters that have the “R” suffix.

 

[GTX JOHN]

I bought something similar from Comp Cams
and they were a disaster. I do not know if they
get they from Johnson or what vender they are from.

 

[Geoff 2]

The circlip shown in post #16 is a beefed up design that allows the lifter pre-load to be set for minimum lifter pump up. The strong design will contain the prod cup in the case of lifterr puimp up, where the paper clip design will punch out. That is the theory....