Measuring Piston-Ring Vertical Clearance

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Piston-ring vertical clearance

1. 1.1  Clean the ring groove on the piston.
2. 1.2  Fit piston ring on the ring groove of the piston. > Piston-ring vertical clearance 
3. 1.3  Guide a feeler gauge into the gap between the piston ring and ring groove and determine the value. > Piston-ring vertical clearance 

   Piston ring	New in mm	Wear limit in mm
   1st compression ring	0.03-0.07	0.15
   2nd compression ring	0.02-0.07	0.15
   Oil scraper ring	Cannot be measured	-