11 25 PISTON WITH RINGS AND BOLTS (M550i xDrive, 2018-2019)
WARNING: This page does not describe the selected car, but rather 28 other vehicles, including the 2023 BMW 540i xDrive, 2023 BMW 540i, 2023 BMW 530i xDrive, 2023 BMW 530i, and 2022 BMW 540i xDrive. However, it is still accessible from the selected car via links, so may be relevant.
1125 TECHNICAL DATA OVERVIEW
| Permissible total wear tolerance between piston and cylinder (engine operated) | |
| Piston installation clearance (piston worn) | 0.25 mm |
| Piston installation clearance (piston new) | |
| Piston installation clearance (piston new) | 0.003... 0.023 mm |
| Piston installation clearance (piston worn) | |
| Piston installation clearance (piston worn) | 0.02... 0.03 mm |
| Piston measuring point "A" | |
| Measuring point (position) A. | 7.5 mm |
| Piston original (new dimension) | |
| Measuring point (position) A. | 88.977... 88.987 mm |
| Piston oversize (0.25) | |
| Measuring point (position) A. | 89.227... 89.247 mm |
| Piston ring 1st groove A | |
| Side clearance. | 0.02... 0.07 mm |
| Piston ring 1st groove H | |
| Annular groove height. | 1.21... 1.24 mm |
| Piston ring 1st groove S | |
| End clearance. | 0.15... 0.30 mm |
| Piston ring 2nd groove A | |
| Side clearance. | 0.015... 0.06 mm |
| Piston ring 2nd groove H | |
| Annular groove height. | 1.51... 1.53 mm |
| Piston ring 2nd groove S | |
| End clearance. | 0.30... 0.50 mm |
| Piston ring 3. Groove-A DSF ring | |
| Side clearance without spiral expander. | 0.02... 0.06 mm |
| Piston ring 3. Groove-A U-flex ring | |
| Side clearance without spiral expander. | 0.02... 0.08 mm |
| Piston ring 3rd groove H | |
| Annular groove height. | 2.01... 2.03 mm |
| Piston ring 3rd groove S | |
| End clearance without spiral expander. | 0.25... 0.50 mm |
| Vibration damper N6302 B44 | |
| Max. permitted radial runout | 0.20 mm |
| Vibration damper N6302 B44-1 | |
| Max. permitted axial runout | 0.20 mm |