Head spacer ?

[ak diesel driver]

https://www.ebay.com/itm/GM-Cylinde...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649

Anyone ever used these? Any thoughts?

 

[Will L.]

I haven’t used any, but a local engine builder used them on various engines. I remember him being hand a set at his shop by parts driver and asking about it thinking it was a weird head gasket. When he said “head shim” I had to ask. He said he hadn’t had any failures out of a dozen or so he had installed in various engines, gas and diesel.

If you were to do it to drop compression you would have to make up for pushrod length in theory. I would think intake and exhaust plumbing has enough room for adjustment to not matter.

Have a damaged head or just something thinking of dropping compression?
Sure is a lot more affordable means of lowering compression than a set of pistons if they make them thick enough to hit the 18/18.5:1
I imagine there is a table that could say “x” thickness equals “Y” compression drop.

 

[MrMarty51]

I wonder if .020 thickness would make that much difference on push rod length.
I too wonder what the compression ratio would turn to after they are installed.

 

[ak diesel driver]

I don't think I would get too excited about pushrod length for only .020. what I thought was weird was the felpro number they reference on the package is just a headgasket.

 

[Will L.]

I think it is saying to use that head gasket.

I dont know the brand of shim that Rick used btw in his shop, he was a Napa parts house addict if that helps.

 

[Husker6.5]

That's a hard addiction to break, but since a lot of their stuff is made off-shore now, should be easier to kick.