To obtain best results from any style
of piston cup, it is recommended that
the piston properly support the heel
of the cup.
Recommended diametral clearance
between the piston and cylinder wall
are as follows:
1" to 2-1/4" .005"
2-1/2" to 4-3/4" .008"
5" to 10" .010"
The height of the machined shoulder
most frequently used to control squeeze
on the heel of the cup is as follows:
Cups 1/8" thick .116/.119"
Cups 5/32" thick .146/.149"
Cups 3/16" thick .178/.181"
The follower plate should be approximately
.110" smaller than the ID of the
cup. To reduce any tendency of the cup
to extrude under pressure a phonograph
finish may be machined on the surface of
the follower plate.
