Head gasket spacer shim

[gerlbaum]

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/332659388525

I've seen guys talk about this before. Never saw this part number before. Anyone ever seen these before when talking about lowering compression.

HSFO69D (2)
6.9l (Navistar) V`8 83-87 Light Truck (DIESEL)
Fel-Pro 8891PT-1
Victor 3789G
Head Thickness New 4.795-4.805” Min 4.795”
.020"

 

[Macrobb]

Just... no. It won't hold up well enough - personal experience with some custom one-off decompression gaskets is that they will end up leaking in a relatively short period of time - even with massive amounts of copper permatex spray.
IDIs like their compression - decompressing results in smoke and hard starting when cold. If you need to take a little off, the pistons can be shaved and that seems far safer to me.

 

[icanfixall]

I have not seen or read anything about these gaskets. Am interested to read more..

 

[IDIBRONCO]

Well where it's only .020" thick, I wouldn't think that it would have the issues that Macrobb said that he had with Justin's decompression gaskets. It says in the description that it's for cases of extreme machining where too much material was removed. I'm interested too.

 

[Macrobb]

I Think it wouldn't have decompression 'issues', just leaking ones. But, my point is that decompression isn't really a goal you want...

 

[gerlbaum]

It looks like it's for when you have valve recession issues. I dunno, but I agree increasing a head gasket thickness isn't the right way to lower compression.

 

[IDIBRONCO]

Agreed. That's the way I read it too.