Thrust washers on rocker shaft

Opinions, opinions, I'm out.

Does this mean I win?
Sorry, couldn't resist.

Stephen Hill said:

Isn't there a school of thought that says that when you shim the rockers to get the correct amount of offset (or offcenter) to ensure the valves rotate, the valves don't rotate anyway?

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Well, I’m about to give up on replacing the valve seals without removing the head….lining up the 12mm temporary rocker shaft has become a joke….finally get the temporary shaft thru the thrust washers into the rocker arm…spent 2 hours trying to get the spring washer…playing with needlenose, hemostats, tweezer, and magnets in place…with the pushrod engaged…takes a surgeon hands and more patience than I have…after 2 days of frustration… I think I’m going to pull the head…haven’t started the other intake seal…this is way worse the replacing the horn
Rod

Triton Thrasher said:

Although that’s not the same as it actually happening.

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True

Carl H said:

I edited my post to say " One straight line scratch." or Wear mark. I do my own valve jobs as I want to do as much as I can to get better flow from the seat area and also fit the stem to guide clearance as Precision Machining recommends with their " Black Diamond" product line. For me it is a labor intensive job to do race quality top ends that hold up for years. It is easier if you do the disassemble yourself and make notes on what you need to correct with a few minor adjustments.

Think of what the wear mark would look like if a valve tip that rotated with an off-center rocker arm adjuster.

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There shouldn't be if the geometry is correct. The softer material between the two would evid. Offsetting the centerline axis of the rocker arm up and down motion a wee bit with the centerline of the valve stem axis perhaps would cause the valve to rotate a smidgen as it might have been designed to do

I find it very unlikely that the factory paid great attention on assembly to where precisely the rocker hits the valve. If so, they would have mentioned it in the workshop manual.
Maybe some rockers hit dead centre, some slightly off.
Not 'designed', but hit and miss. Typical of their sloppy engineering.

not a Norton but interesting

Update:
after removing the head I decided to pull the barrels…the piston on 1 cylinder was covered with carbon/oil…the barrels are still standard with a honing…but I found the “extra” rocker shim laying on top of a lifter. Glad I pulled the barrels!
Thanks for all the advice,
Rod

ludwig said:

No, just look at the wear marks on the valve tip.
I just looked at maybe 20 old valves, and they all have linear wear marks.
They did not rotate.

edit: @CarlH, we posted the same time.
I also use bronze spacers

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Just looked at all the old valves i have, all show linear contact.
I owned a VW van years ago that had an Audi engine in it. Had to overhaul the head and found a broken valve spring seat. This spring seat incorporated a kind of thrust bearing that made the valve assembly rotate. I think it was an overhead cam engine and it had valves under buckets although i could be mistaken, It was 40 yrs ago.
Modern OHC and DOHC engines using bucket type cam followers have the cam offset from centerline of the bucket to promote bucket rotation. The valve won't rotate though unless the spring seat is designed to rotate.