Clarification on rocker spacing

[beanhead]

I see where the preferred side clearance for aftermarket rockers is (generally) about .015". My question is, how exactly do you set that clearance...is that when you can get the feeler gauge on any one side of a one rocker at a time? Or, does that mean that as they sit they will have the .015 on each side of each rocker (which seems like too much slop, that would be .060 total of space between any two hold-downs) I hope my question makes sense...in other words (I think?!) as the rockers sit all cuddled up together, I should be able to slide the feeler gauge in alongside a selected rocker and get only the desired clearance, at this same moment putting the gauge in pushes the other rocker and spacers together with no clearance..but as I move the gauge down along the sides of each arm I will get the proper measurement...clear as mud? Thanks!

 

[BSB67]

0.015" total for a rocker pair is probably the minimum you would want. If they are aluminum rockers maybe go a bit more.

 

[beanhead]

0.015" total for a rocker pair is probably the minimum you would want. If they are aluminum rockers maybe go a bit more.

Thanks BSB67, I will be using aluminum and was planning on a bit more room for expansion..you have answered my question that the clearance measurement is the total for each pair thanks.

 

[gkent]

.030 is good for aluminum rockers - total for a pair.

 

[Kozlow]

From Hughes installation instruction sheet:

Total side clearance between a pair of rockers should be 0.005”/0.015”

 

[PurpleBeeper]

School me guys......my Isky ductile iron rockers have springs between them, so nothing is really "loose" for a side clearance. If you compressed the springs, it would be maybe 1/4" clearance or more. So....do newer aluminum rocker have just spacers & no springs???

 

[BSB67]

I've seen more than once aluminum rockers lockup and turn blue, and cause piston and valve damage. If you are using aluminum hold downs, and aluminum spacers, simple coefficient of thermal linear expansion suggest that you'll be in trouble at 0.010"

 

[OSDart]

Set up the rockers with the spacers only. No shims! Snug the rocker shaft hold downs. Measure the total gap between each set of rockers. Using shims, set to desired gap(.015-.025). Remember, the rocker hold downs can be adjusted side to side a fair amount. Might be hard to see, but the total gap is marked on the yellow tape. Example: If total gap is .098", subtract the desired gap from .098. This will be the shim pack required. A little time consuming. I set mine at .018"

 

[not so famous bob]

Set up the rockers with the spacers only. No shims! Snug the rocker shaft hold downs. Measure the total gap between each set of rockers. Using shims, set to desired gap(.015-.025). Remember, the rocker hold downs can be adjusted side to side a fair amount. Might be hard to see, but the total gap is marked on the yellow tape. Example: If total gap is .098", subtract the desired gap from .098. This will be the shim pack required. A little time consuming. I set mine at .018"

View attachment 732609

I have posted this in other threads. I run .009-.011 clearance between each pair, use 4 feeler gauges per side and leave them in while torqueing down, no problems, and have excessive header under hood heat. No rocker problems.
I have had the rocker stand to rocker clearance change while torqueing if I don't use feelers in all while tightening---------