Valve spring shims on top of the springs?

[matmaster]

I had a local head shop rebuild my 1G head. They placed copper shims between the valve spring and retainer. I have always seen the shim under the valve or valve seat. Should I be concerned about this?

 

[DSMeclipse4G63]

probly, the shim needs to be under it to affect the spring in the way you want.
Andrew

 

[4pistons]

I'd be concerned. If that shim is too thick the spring will unseat from the retainer. That's usually not a concern if it's on the bottom as the spring can't fall off, but on top it can.

Putting the shim on top also adds weight to the valvetrain as it must now move with the valve. This will effect top end performance and could induce valve float earlier.

I'd bring it back and insist that it be done properly.

Rick - '91 GSX

 

[Defiant]

Ask the shop. I seriously doubt they're copper spacers, probably just plated for identification.

Another thing spacers under springs do is help reduce the amount of heat the head conducts into the springs. It doesn't make sense to me, but maybe they have a better story about it.

 

[DSMeclipse4G63]

I'd be concerned. If that shim is too thick the spring will unseat from the retainer. That's usually not a concern if it's on the bottom as the spring can't fall off, but on top it can.

Putting the shim on top also adds weight to the valvetrain as it must now move with the valve. This will effect top end performance and could induce valve float earlier.

I'd bring it back and insist that it be done properly.

Rick - '91 GSX

that and cause the valve spring to push harder into the cylinder head then before and wear into the aluminum.....which of course isnt good.
Andrew