BMW R 1150 RT Repair Manual page 81

Technical Data 11 Engine
Pistons
Piston dia.
A
Wear limit
B
Wear limit
AB
Wear limit
Installed clearance
Total wear clearance of piston and cylinder
Piston pin bore dia.
Weight classes
Weight difference in one class
Direction of installation
Piston rings
Installed direction of piston rings
1st groove
asymmetric piston ring,
curved, oval section
Height
Wear limit
Gap
Wear limit
Float
Wear limit
2nd groove
Micro-taper compression ring
Height
Wear limit
Gap
Wear limit
Float
Wear limit
R 1150 RT
(Measuring plane A — see Checking pistons and
cylinders)
mm (in) 100.971...100.983 (3.9753...3.9758)
mm (in) 100.895 (3.9723)
mm (in) 100.983...100.995 (3.9757...3.9763)
mm (in) 100.905 (3.9727)
mm (in) 100.979...100.987 (3.9756...3.9759)
mm (in) 100.900 (3.9725)
mm (in) 0.005...0.029 (0.0002...0.0011)
mm (in) 0.12 (0.0047)
mm (in) 22.005...22.011 (0.8663...0.8666)
+ and —
g (oz.) 10 (0.353) (complete with pins and rings)
Arrow on piston crown pointing to exhaust side
Production locating point towards exhaust side
(see Installing piston)
"Top" marking uppermost
mm (in) 1.170...1.190 (0.0461...0.0469)
mm (in) 1.1 (0.0433)
mm (in) 0.1...0.3 (0.0039...0.0118)
mm (in) 0.8 (0.0315)
mm (in) 0.030...0.070 (0.0012...0.0027)
mm (in) 0.15 (0.0059)
mm (in) 1.170...1.190 (0.0461...0.0469)
mm (in) 1.1 (0.0433)
mm (in) 0.2...0.4 (0.0078...0.0158)
mm (in) 0.8 (0.0315)
mm (in) 0.030...0.07 (0.0012...0.0027)
mm (in) 0.15 (0.0059)
11.11