Rocker shaft shims

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Mojack

Mojack

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I've never used these before, but I'm building a budget BB for my Trailduster.
Rocker Shaft Shims
I've got a little too much lifter preload and I know the pros and cons. I just wanted to know if anybody could tell me if these shims are steel or alum, just curious.
 
More head rocker stands have probably been cracked by those shims than all the other reasons put together
 
The shims are fine to use . Don't over torque and only use one.
 
They don't work! They leave a gap between the shaft and the stand and the oil just runs out and never gets to the rockers
 
brian6pac said:
They don't work! They leave a gap between the shaft and the stand and the oil just runs out and never gets to the rockers
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Hum, been used by many, including myself, never an issue. That is how we set up hydraulics with stamped rockers back in the day.
 
Mojack said:
Thanks guys, that's what I need to know. It's going to be a lopo motor, I think they will be ok.
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If anything trim a bit off the ends before install so the shaft will not push out on the sides of the pedestal when you torque it down. Stamped steel rockers?
 
threewood said:
If anything trim a bit off the ends before install so the shaft will not push out on the sides of the pedestal when you torque it down. Stamped steel rockers?
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That's a good idea, I'll look at it carefully when I tighten it down.
Yes non adjustable stamped steel.
Thanks
 
Mojack said:
That's a good idea, I'll look at it carefully when I tighten it down.
Yes non adjustable stamped steel.
Thanks
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Do some looking on hughs engines test site , if u just have to use them -----------------
 
I've made them from brass roofing flashing before. Drill, tin snips, stacked as needed.
Very inexpensive, and they mold easier to the rocker stands.
 
kowalski440 said:
I've made them from brass roofing flashing before. Drill, tin snips, stacked as needed.
Very inexpensive, and they mold easier to the rocker stands.
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Hmmm... I've been thinking about using some stainless I've got... but I'm liking the sound of the brass "molding"

Thanks
 
Here are the ones I made about 6 years ago to fix a problem with roller tip rockers on a 440. I used a 7/8" pipe split then a 7/8" ball mill down the center to make it fit.

IMG_0639.JPG
 
I think one of the selling points of the store bought shims is they are tapered or used to be tapered at the tops. Think about what you are trying to do here and it makes it easier to understand why they have split the head pedestals.
 
Alright Noob Question
How do you determine if shims are necessary
Should the pushrods be able to spin
 
pittsburghracer said:
I think one of the selling points of the store bought shims is they are tapered or used to be tapered at the tops. Think about what you are trying to do here and it makes it easier to understand why they have split the head pedestals.
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Yes, it's easy to understand the problem and sounds like the aftermarket has taken this into account . I'll just have to order a set and find out.
Thanks
 
If you buy them from Mancini they are just a piece of sheet metal not tapered and will hit the top of the pedestal and not the bottom.
 
Mojack said:
I've never used these before, but I'm building a budget BB for my Trailduster.
Rocker Shaft Shims
I've got a little too much lifter preload and I know the pros and cons. I just wanted to know if anybody could tell me if these shims are steel or alum, just curious.
Click to expand...
If the heads are otherwise stock, you may want to consider just getting a shorter pushrod. That would be the correct way to compensate for too much preload due to block and head machining. The shims mess with the factory engineered rocker geometry when using factory valvetrain components, not to mention, risk breaking the stands.
 
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