From: Ray Gee <sfq2@flash.net>
To: zdoc@yosemite.net <zdoc@yosemite.net>
Date: Wednesday, May 06, 1998 6:40 PM
Subject: Z32 engine

Ray writes:

>Doc,

>I have a question for you in regards to my 1992 300ZX non turbo engine.
>I'm in the process of bebuilding it and in the factory manual, it says
>to select the piston with the same grade number punched on the block.
>This is all new to me. What does it mean? I've bebuilt numerous L
>series engines and never seen this before. I bored the engine to the
>next oversize and purchased new pistons. I don't see the numbers on the
>pistons that the manual is talking about. The manual also says that if
>new bearings are used, the grading should match the stampings on the end
>of the crank. Also news to me. Help!
>
>Ray

Doc writes:

Ray,

Doc here, you do not have to be concerned about this coding system
since you have already bored the engine for the new pistons. This was a
factory designation for the original type pistons that are lazer measured
for tolerances. The most important thing is that you clearance the
measurements to the factory specs. In other words checking the piston to
cylinder wall clearances, the big end free play on the rods, the ring end
gap in the cylinders, and so on. Please use plastiguage for the rod oil
clearance check at the bottom end too. That should shed some light on the
question.......
ZDOC OUT

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