Valve springs insulators and mushroom valve adjusters

Many engine shops do not understand ‘old’ engines.
They think they’re doing a ‘better’ job by using tighter tolerances.
Often they are quite wrong.

Fast Eddie said:

Many engine shops do not understand ‘old’ engines.
They think they’re doing a ‘better’ job by using tighter tolerances.
Often they are quite wrong.

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If the guide clearance range is stated by KW for their materials, why would the engine manufacturer spec need to alter that?

Also a bit OT, but triggered by ILLF8ED's post.

Those old advertisements are pretty misleading. I still have a set of those 4130 push rods from Alloy-Tech. They don't save weight in the valve train. The stock Commando pushrods weigh 29.7 grams each, and the 4130 rods weigh 50 grams each.

Here is the data I measured a few years back for standard length Commando intake (the longer one) push rods :

Stock rod is 29.7 g.

Alloy-Tech 2024 aluminum rod with steel ends is 29.8 g.

Alloy-Tech 2024 aluminum rod with hard anodized aluminum ends is 22.7 g.

Alloy-Tech 4130 rod with steel ends is just over 50 g.

Carbon fiber rod with steel ends is 28.3 g.

Ken

Tornado said:

If the guide clearance range is stated by KW for their materials, why would the engine manufacturer spec need to alter that?

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Why? As I said, they think they know better and / or they think ‘tighter’ is better.

I had to be uber specific and quite strong in insisting on specific clearances with my last Norton rebore. The very experienced machinist was convinced he knew better than the very experienced Norton piston supplier !

Fast Eddie said:

Why? As I said, they think they know better and / or they think ‘tighter’ is better.

I had to be uber specific and quite strong in insisting on specific clearances with my last Norton rebore. The very experienced machinist was convinced he knew better than the very experienced Norton piston supplier !

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What i'm asking is the guides and valves must expand at a rate known to KW. How does using them in an old type engine alter that? The spec's in our workshop manuals are for the original materials, not modern ones. Heat is heat and should not change in older engines. Is it something to do with the rocker geometry needing more valve clearance in guides? Or is it that our air cooled engines run hotter than kW sets their material expansion specs at?

Tornado said:

What i'm asking is the guides and valves must expand at a rate known to KW. How does using them in an old type engine alter that? The spec's in our workshop manuals are for the original materials, not modern ones. Heat is heat and should not change in older engines. Is it something to do with the rocker geometry needing more valve clearance in guides? Or is it that our air cooled engines run hotter than kW sets their material expansion specs at?

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Air cooled engines run hotter than liquid cooled engines. I never commented on KW specs. My comment was about machinists who ignore the specs.

If you build it to stock specs it will usually work well enough. If you build it to something other it may work better or it may
not work for long. I would go with the shop who has a good rep with whatever you are working on. Experience is worth more than a little.

Onder said:

If you build it to stock specs it will usually work well enough. If you build it to something other it may work better or it may
not work for long. I would go with the shop who has a good rep with whatever you are working on. Experience is worth more than a little.

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the critical part is “rep. with WHATEVER you are working on”......for example, Norman White lists firms he uses, in his Restoration book.

How many area still trading? How many are still run by the person that ran the place when Norman
was using them? Im only asking not slagging here.

Onder said:

How many area still trading? How many are still run by the person that ran the place when Norman
was using them? Im only asking not slagging here.

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No idea, but a call to Norman would answer when he last used them.