piston specs

[Tadpole]

Hi evereyone,
After the nice surprise of finding out that I have 2.7 RS spec pistons and cylinders I was wondering why the Hayne's repair manual lists three different sets of specifications.
What does the LS version stand for?

Then there is: Piston Diameter Cylinder Bore

0 89.960 to 89.972 90.000 to 90.012

1 89.972 to 89.984 90.012 to 90.024

2 89.984 to 89.996 90.024 to 90.036

My cylinder bore meassurements fall into the number 2 column. Do I have to get over sized piston rings or will stock piston rings still be OK? Thanks

[tom1394racing]

Mike

The Haynes manual is referring to the standard 2.7 CIS pistons.

The key to determining if your set is re-usable is the top ring land width or side clearance on the pistons and the piston to cylinder clearance.

Piston to cylinder clearance should be 0.004" average or less. The top ring land width should be 0.165mm or less.

Here's and example of a typical piston and cylinder inspection.

Let me know if you need some help in making these measurements.