Rocker shims = NO rocker shaft oiling

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Mojoe9955

Mojoe9955

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While rebuilding my motor, I had the heads "decked" and used the 1121G head gasket. In doing so my preload was a little below and at the lower end of the 0.020 to 0.060 range. To get some more I ordered shims from Mancini and got it to like 32 to 37 so I felt pretty good. Fast forward a few weeks to today when I got everything sorted and anticipated dropping it in tomorrow last thing today I wanted to prime it on the stand, and guess what...no oil. First I thought the rockers where upside-down or backwards, I spun the pump, maybe faster...clockwise of course I thought the pump might be bad but could hear some gurgling so I cracked the filter some...oil everywhere so the pump was working. I took a break, had some coffee and a donut, then remembered the shims. I took the shims out of oil hole pedestals and in a few minutes of spinning and turning I felt like Jed Klampett...now I'm missing the shims and the shafts have a gap at the oil hole. Anyone else have this problem? I'm thinking of using the Dremel and cutting the shims in U shape with a little flare to let the oil flow and allow me to torque the shafts.
Thoughts?

17001735988356797323537372172714.jpg
 
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Rocker Arm Oiling question

First time engine builder here. Actually Assembler is more accurate. I bought a crate 408 short block and doing final assembly. I had everything assembled and went to spin up oil pressure using a drill and noticed I was not getting any oiling at all to the rocker arms. Engine was spinning up...
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Cheers
 
Sounds like the shims are not clearanced for the rocker shaft oiling hole. I would look at the oiling pedestal and get a file and file reliefs in the shims to match the oiling holes in the pedestals.
 
Ok, so we have a non adjustable valvetrain. Were the head decks just cleaned up. Cant believe that could throw the geometry off much so wouldn't a proper pushrod length give you what you need and just leave those shims on the garage shelf?
 
You have to turn the crank while running the oil pump during priming. Each side only has a few crankshaft degrees where oil will pass up to each shaft. No turn the crank, very little chance the rockers will get oil.
 
The hole in the shim is too small, it needs to be enlarged to match the oil relief hole on the stand. BTDT
 
The only shims I've seen were nothing like those. They were sort of oval, and had oblong holes in them NOT a "U"
 
fishmens67 said:
The hole in the shim is too small, it needs to be enlarged to match the oil relief hole on the stand. BTDT
Click to expand...

If it's a round hole, I found when the shim is bent to the stands diameter, the hole becomes oval, and will pass oil freely to the shaft, at least when I use them, they do.
That'd be a pretty severe oil leak at 60#s constant pressure.
That's why I posted the link, the rocker shafts only get oil a "spurt" at a time, when the cam/bearing holes line up every 2nd crank revolution.
 
fishmens67 said:
Yep generic, those are crush fit. lol
Click to expand...
Except they don't, I've made 2 sets of My own, & fixed a set from Mancini's. They have to be fat in the middle, & taper off to the top of the pedestal, there's no way to wrap flat stock around a shaft & have the same inner & outer radii....it will only contact at the top edges of the pedestals where the shaft pinches them & oil will leak out from under the shaft at each bolt, thin shim not so much, thick shim a shitload.
 
The problem is the shim itself. The open end of the U is allowing the oil to pump straight out of that gap.....rather than entering the shaft where you want it go. The shim needs to have a round or oval hole so that it seals all the gaps.
Every hyd lifter I have worked with has had well over 0.100" of travel, with the vast majority going to 0.150" or more. The pre-load can be anywhere within this range. So most likely the shims are not needed if they are being used to set pre-load. The lower range of pre-load might be to reduce the effects of lifter pump up, should that occur, but the correct fix is to use stronger springs to control the valvetrain.
 
Killer6 said:
They have to be fat in the middle, & taper off to the top of the pedestal,
Click to expand...
The ends of the shim need to be trimmed to be at the bottom of the pedestal, you don't want them extending to the top and surrounding the shaft.
 
What I would do.....Hello, Smith Brother's Push Rods......hi how's ya day, I need a,set of push rods. A week later, In your Mail box one nice well made push rods.
 
So….. you had not enough lifter preload, so you put shims under the rocker shafts. Would that not raise the shafts and decrease the preload even more? Also, decking the heads would increase not decrease the preload.

Am I missing something in your explanation?
 
d55dave said:
So….. you had not enough lifter preload, so you put shims under the rocker shafts. Would that not raise the shafts and decrease the preload even more? Also, decking the heads would increase not decrease the preload.

Am I missing something in your explanation?
Click to expand...
Yeah, You're missing something. There are 2 schools of thought in setting lifter preload;
1) Very little preload, so that at rpm, the lifters are limited in their ability to "pump up" during lost valve motion. I am in that camp, and if You've watched enough high speed/sample-rate video of valvetrains, there is always some lost motion no matter how good You think your springs are. If they pump up, the valves don't fully seat & you've got a sag in the curve or the top end is soft. Make no mistake, even if the valve seats, it's going to bounce a little anyways.
2) Set the preload almost to the bottomed-out position, so that any operating deflections can be compensated for, and if the lifter oil supply/feed actually causes the lifter to bleed down at rpm, it can only lose a tiny bit of lift & is less likely to toss an unguided pushrod out. Vizard is in that camp.
In either case, You are compensating for shortcomings of a hydraulic tappet, some can be minimized & some come with the territory.
 
Wow! Lots of typing there ^^^
So I’ve tried preloading a hydraulic lifter to the bottom plunger depth like said above and ended up after a few pulls with a lifter tick. I Pulled the intake and found the retainer clips fell out of the lifters. In pieces but all were in bottom of pan.

I was told by the machine shop not to do that with certain lifters - comp cams for one - as they need the pressure of start up to expel air while pumping up and if too much slop- the clips fall out. These were wire type clips and not c clips. Has technology changed or did I mis read the above info?
 
Bewy said:
The problem is the shim itself. The open end of the U is allowing the oil to pump straight out of that gap.....rather than entering the shaft where you want it go. The shim needs to have a round or oval hole so that it seals all the gaps.
Every hyd lifter I have worked with has had well over 0.100" of travel, with the vast majority going to 0.150" or more. The pre-load can be anywhere within this range. So most likely the shims are not needed if they are being used to set pre-load. The lower range of pre-load might be to reduce the effects of lifter pump up, should that occur, but the correct fix is to use stronger springs to control the valvetrain.
Click to expand...

d55dave said:
So….. you had not enough lifter preload, so you put shims under the rocker shafts. Would that not raise the shafts and decrease the preload even more? Also, decking the heads would increase not decrease the preload.

Am I missing something in your explanation?
Click to expand...
Yes maybe I am. "Setting" the lifter preload with stock rocker arms doesn't seem to me to be possible as there is no adjustment.
Reading about how to accomplish this pretty much scrambled my mind as I'm a bit dyslexic. With that in mind let me start over.
Stock rocker shafts, and valves
I had the heads surfaced and 3 angle valve job.
New V258H12 cam/lifter kit.
New 901Comp springs and appropriate hardware.
I'm using a .028 head gasket thinking it will boost my compression up a bit.
Using this info and forgetting the shims, can I theoretically use my stock length push rods?
 
Syleng1 said:
Wow! Lots of typing there ^^^
So I’ve tried preloading a hydraulic lifter to the bottom plunger depth like said above and ended up after a few pulls with a lifter tick. I Pulled the intake and found the retainer clips fell out of the lifters. In pieces but all were in bottom of pan.

I was told by the machine shop not to do that with certain lifters - comp cams for one - as they need the pressure of start up to expel air while pumping up and if too much slop- the clips fall out. These were wire type clips and not c clips. Has technology changed or did I mis read the above info?
Click to expand...
If You had set the preload with the plunger almost bottomed, there'd be little play, & the cup wouldn't even touch the clips, ever. It may take a bit longer to pump up with limited travel, but other than the vibration frequency from the "tick", there's nothing to cause the clips to fall out....I figure that to be the case. If You set the preload really shallow as I do, the cups are all going up & down almost full travel 'til they pump up, that makes a lot more noise/vibration. I have yet to have that happen with any so far, Comp, Mopar, Crane, Lunati, Engle, knock on wood I guess. Internal snap ring is superior to the wires, consider that plenty of solid cams that tick & clack away have clips holding the pushrod seats in just the same.
 
Mojoe9955 said:
Yes maybe I am. "Setting" the lifter preload with stock rocker arms doesn't seem to me to be possible as there is no adjustment.
Reading about how to accomplish this pretty much scrambled my mind as I'm a bit dyslexic. With that in mind let me start over.
Stock rocker shafts, and valves
I had the heads surfaced and 3 angle valve job.
New V258H12 cam/lifter kit.
New 901Comp springs and appropriate hardware.
I'm using a .028 head gasket thinking it will boost my compression up a bit.
Using this info and forgetting the shims, can I theoretically use my stock length push rods?
Click to expand...
You did the right thing preload-wise, yes, You are setting the preload by shimming. You didn't say how much was taken off the head, so You could end up with exactly the same preload You started with, depending on the gasket You pulled.
There's also the element of stock rocker geometry that's being buried here, for that @B3RE could chime in, nobody knows more about this topic than this cat.
 
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I'm not sure how much was off the head and the machine shop couldn't tell me, which is another story. On my initial assembly though everything seemed really tight pushrod wise. The pushrods need to spin at some point...correct?
Probably not at top dead center with the intake valve on compression, but it seemed I had to back it off quite a bit to get it to spin. Leading me to believe the push rods were too perhaps too long.
 
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