3.0L Cylinder Base Spacers

[porschedude996]

Please School me if and how to measure and install Cylinder Spacers or Metal Base Gaskets. Also is this a wet gasket application?

My gasket kit came with a single set of copper cylinder base gaskets. I see in Porsche’s PET catalog that there are several thicknesses of gaskets. Application shows one for SC, one for M930.10, and one with no application data.

Are the spacers just thinner or thicker copper gaskets? One notes Std .25mm, then the M930.10 says oversize .50mm. My engine is Late 1983 3.0L US consumption (49 State).

With new cylinders, is checking or measuring something that needs to be accomplished on a bone stock engine?

Is it I measure the deck height at the piston corner to the top of the cylinder?

I do plan on checking the valve to piston clearances with clay. I should also place some clay where things get tight with the CIS pistons.

[Henry Schmidt]

As a general rule, you want to check everything. Stock Mahle replacement Ps&Cs should clearance without too many challenges. The .25mm base gasket should give you the .040" deck suggested +or- a little and the .50mm shim is generally for an engine where the spigots were decked and/or the heads resurfaced. There is no hard fast rule and searching for an absolute spec is a fools errand.

[porschedude996]

Thanks Henry, always a voice of reason.