Shims, how much can they be sanded down?

[JoeP]

I'm doing a valve job on a testastretta (06 749). Can the opening shims be sanded down by as much as 0.06mm and remain structurally sound?

[He Man]

yes. theres not as much load on those shims as you think.

The EMS ones are A2 Steel and have a hardness rating on the rockwell c scale of 60 or so and its suppose to be 300+KSI compressive strength.

aka, if it breaks, its most likely major mechanical failure on the motorcycle or a manufacturing defect.

one of the more important things is if you can shim that much off evenly.

[motoxmann]

one of the more important things is if you can shim that much off evenly.

that was what I was going to say too. you can take off a whole lot more than 0.06mm. but the major thing would be doing so while keeping it even all around. sand it down in a figure 8 pattern, and occasionally rotate the shim in your fingers. this will ensure the most even sanding

[Slide Panda]

Another tip for even sanding is a smooth base surface. Lay up you fine wet/dry paper, with a bit of water on the back on a sheet of glass. I have a chunk of tempered glass from a bathroom shelf that I use for things like this and smoothing the bottom of my CPU coolers back in the day.

[JoeP]

Ah, this board is full of wisdom. I got everything back together and the clearances are spot on. 
Time to tune it now.

[motoxmann]

Another tip for even sanding is a smooth base surface. Lay up you fine wet/dry paper, with a bit of water on the back on a sheet of glass. I have a chunk of tempered glass from a bathroom shelf that I use for things like this and smoothing the bottom of my CPU coolers back in the day.

yes, that too. I personally use the bottom of a high quality multi-layer stainless steel fry pan haha

Ah, this board is full of wisdom. I got everything back together and the clearances are spot on. 
Time to tune it now.

good to hear. enjoy!