Valve shim adjustment tool

Here's my tool :)

The red handled shim tool was purchased from a forum member. I haven't tried it yet. The other one that I mangled was for my race car, it didn't work properly :(

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I was afraid to look at the pics after you said "here is my tool". :eek:

The end of the "spoon" lever has a bit of a 'S' shape. That would help to get access and pry the bucket down. The generic pry bar I showed only has one bend so it might not work quite as easily. But the inexpensive one from H.F. could be heated and bent at that spot without loosing the temper at the end (if it is even tempered). The tip could also be sharpened as suggested by "phillips82" to help get it between the cam and tappet.
 
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I use a tool I bought from a Fiat dealer in the 70s to depress the tappets and a tool I made from a tweezer to pop the shims out. Works like a charm!

Valve adjusting tools.jpg
Valve adjusting tool depressing tappet.jpg
Tappet depressed, shim popped out with tweezer.jpg
 
I do the same, but that's what wears out the tool you show (around the indicated area, below). What we are suggesting here is to not use that tool to depress the tappet. But use a lever (pry-bar, spoon) to depress it, then use the tool you show to hold it there while you change the shim with your tweezers. The spoon/lever is wedged between the cam lobe and the center of the shim and levered to pry it down. That saves the other tool from doing the heavy work.

Valve adjusting tools.jpg


I've even seen where the edges of the tappet buckets look a tad "nackered", I suspect from using the first tool to compress them...and possibly the tool slipping off the edge of the bucket (especially happens as the tool wears out).
Frankly I need to change my habit of just using the one tool to depress and hold the tappet, and start using two tools as described.
 
And now that I look closer, I see why the spoon has the "S" shape. The second 'reversed' bend (higher up the neck) helps clear the edge of the cam-box casting when the tool is levered downward:

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Does the spoon tool push the bucket down by scraping against the shim and cam? Is there any ffear of scarring either? I know both should be hardened steel but so too are the tools. Would it be best to make a spoon out of brass much like a dead blow hammer? I guess it might depend on if the tool is used more as a pry bar or simply a wedge with no stresses caused by lifting the handle.
 
I've wondered the same question. I would view it as a combination of some 'scraping' to get the tool into position, and then some 'levering' to apply the downward pressure. I suppose you could lessen the 'scraping' by rotating the cam away from the shim, place the tool in position, then lever it down. But to some extent the "wear" potential is not much more than the same 'scraping' when the other tool is used to wedge the two adjacent buckets down, just in a different (and perhaps less critical) location. But its not likely enough to worry about, especially when compared to the normal 'scraping' the cam does on the shim all the time. After all these are intended to rub against each other in normal operation. And I'd suspect the tool's temper is less than the cam/shim's (especially if you use a cheap tool). However your suggestion of using a softer material (e.g. brass) for the spoon is worth consideration. Or maybe Teflon coat the end of it? That's also where sharpening the tip will help, to get the tool in between the two items.
 
Dr.Jeff said:
I do the same, but that's what wears out the tool you show (around the indicated area, below). What we are suggesting here is to not use that tool to depress the tappet. But use a lever (pry-bar, spoon) to depress it, then use the tool you show to hold it there while you change the shim with your tweezers. The spoon/lever is wedged between the cam lobe and the center of the shim and levered to pry it down. That saves the other tool from doing the heavy work.

View attachment 10716

I've even seen where the edges of the tappet buckets look a tad "nackered", I suspect from using the first tool to compress them...and possibly the tool slipping off the edge of the bucket (especially happens as the tool wears out).
Frankly I need to change my habit of just using the one tool to depress and hold the tappet, and start using two tools as described.
Click to expand...
If you are using this tool correctly the surfaces where the red arrows are should not experience much wear because the tappet rotates as the tool is depressed so there should be only vertical force (no rubbing). There probably is some wear where the tool wraps around the camshaft but that's probably not a big deal.
 
Only issue I see is the shim and cam have a film of oil when it's running and it would be far easier to ding either the shim or the cam lobe when they are dry. Maybe some high pressure grease would help.

Also how do you depress both buckets to get the other tool in place? I only have 2 hands, sometimes it's tough deal with the limitation...
 
dllubin said:
If you are using this tool correctly the surfaces where the red arrows are should not experience much wear because the tappet rotates as the tool is depressed so there should be only vertical force (no rubbing). There probably is some wear where the tool wraps around the camshaft but that's probably not a big deal.
Click to expand...

The rotation of the bucket actually creates a sheering action. I found when I was making the prototypes for my tool the buckets would sheer off a very thin shaving some times and after a lot of use you could really see the wear. I changed the design to incorporate a 5 degree side taper on the ramps so the main contact starts further away from the edge of the tool, that stopped the shearing action I observed but the wear was still heavy. I went to case hardening the working end of the tool and the wear went way down, you can still see where it rides on the buckets but no bad wear. I tested it for hundreds of cycles thinking that should cover any hobby engine builders.
 
bpimm said:
how do you depress both buckets to get the other tool in place?
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Another good question. As I said, I've never used the two-tool method. But I believe the idea is to rotate the cam so one tappet is pushed down by the cam lobe, and you use the spoon-lever to push down the other tappet. Then both tappets are down and you insert the second tool...only need two hands.
 
bpimm said:
and after a lot of use you could really see the wear.
Click to expand...
All I know is my adjusting tool has a lot of wear on it, so something creates it. And as I said, I've always done the "one-tool" method, forcing both buckets down with the tool.
 
Brian's statement about needing three hands brings back my earlier thought.

Design a tool that is secured to the head with a pivot-rod that travels along the length of the head. Then a lever pivots on that rod to press down the tappets. There is a similar such set-up for other heads. And it might be easy to make it with two pivoting levers that are tied together. That way one hand can depress two adjacent tappets at the same time.
 
Step 1: Turn the motor over so the cam lobe is pointed away from the shim.

Step 2: Measure the gap between shim and cam
.
Step 3: Insert the spoon between the shim and cam to depress the shim/bucket/valve.

Step 4: Inset the valve adjusting tool so it catches the edge of the shim bucket and the cam.

Step 5: Remove the spoon.

Step 6: Remove and replace the valve shim.

Step 6: Insert the spoon again.

Step 7: Remove the valve adjusting tool.

Step 8: Remove the spoon again.

Step 9: Recheck the gap between shim and cam.

DONE! No damage to anything. No excessive or odd wear.
 
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