Piston Ring Measurements

M52 5.2L/2.8L Piston rings

M52 2.5L Piston rings
1st groove
End clearance	mm	0.1 - 0.3
Axial play	mm	0.020 - 0.060
2nd groove
End clearance	mm	0.2 - 0.4
Axial play	mm	0.030 - 0.065
3rd groove (oil scraper )
End clearance	mm	0.25 - 0.5
Axial play	mm	0.030 - 0.065

M52 2.8L Piston rings
1st groove
End clearance	mm	0.1 - 0.3
Axial play	mm	0.020 - 0.060
2nd groove
End clearance	mm	0.2 - 0.4
Axial play	mm	0.030 - 0.065
3rd groove (oil scraper)
End clearance	mm	0.25 - 0.5
Axial play	mm	0.020 - 0.060