Porshe 911 (997). Manual - part 28

Piston with restraining strap

7. Position clamping tool universal piston ring restraining strap, 75 - 125 mm NR.55 on the piston; when

doing so, ensure that the piston rings are positioned correctly. Adjust restraining strap to piston diameter,
use tensioning lever -1- and tensioning screw -2- to fine-tune the adjustments.

8. Coat cylinder bores 1-3 with plenty of new engine oil.

Piston in cylinder bore

9. Insert piston, together with connecting rod, into cylinder bore 1, universal piston ring restraining strap,

75-125 mm NR.55

 must lie evenly on cylinder surface.

Piston - installation position in crankcase

10. Pay attention to direction of assembly: arrow on piston crown always points to flywheel side

Diagnostic system: reading out fault memory and activating systems

Installing pistons

269

Pressing piston into cylinder bore

ATTENTION

Incorrect and careless assembly of pistons.

Component damage (pistons, piston rings, cylinder line)

• 

→ Assemble pistons carefully and gently.

→ Stop process immediately if there is increased resistance during assembly; eliminate the cause of the

problem.

11. Hold the piston ring restraining strap firmly and press piston in a cable into the cylinder bore using a

plastic mandrel.

12. Check installation position of connecting rod: In the installation position, the recesses of the

twist lock in the connecting rod bearing point towards the oil pan.

Connecting rod bolts

13. Turn crankcase through 180° on assembly support, position marked connecting rod cap with new,

greased bearing shell and screw in two new connecting rod bolts.

14. First, screw in connecting rod bolts to the required torque and tighten to the specified torque angle.

Then loosen the bolts again. The final tightening is performed again with an initial tightening per
the torque and the concluding tightening is performed with the torque angle wrench. → Initial
tightening: 15 ftlb.

 ; → Final tightening - torque angle: 110 °

15. Repeat steps 3-14 for the pistons/connecting rods on cylinders 2 and 3. For the assembly of cylinder 2,

bore 'U5' will be fixed with the fixing pin after the crankshaft is turned on the belt pulley/vibration
balancer; for the assembly of cylinder 3, bore 'U6' will be fixed.

16. Remove the cylinder-head screw from crankcase 1-3 using the spacer sleeve 9613.

Only the following sealants may be used to seal the engine:

Loctite 5900

• 

Diagnostic system: reading out fault memory and activating systems

Installing pistons

270

Drei Bond or Loctite 1209 (optional)

• 

Aligning timing chain and connecting rod

17. Prepare crankcase half 4-6 to fit it onto crankcase half 1-3. Carefully grease sealing faces of both

halves with acetone. Align connecting rods 4-6 vertically upwards and fold timing chain.

18. Apply sealant to the sealing face of crankcase half 4-6.

Application of sealant and tightening sequence for crankcase

19. With the help of a second person, place crankcase half 4-6 in position on crankcase half 1-3. Knock

gently on crankcase half 4 -6 using a plastic hammer. Pull timing chain out through chain space using a
bent welding wire.

Coated screws for cross bolt connection

Diagnostic system: reading out fault memory and activating systems

Installing pistons

271

20. Position four new, coated M6 x 35 Torx screws -1- on flywheel side.

Cross bolt connection on belt side

21. Position seven M6 x 35 Torx screws on belt pulley side -1- ; then fit special tool centring

mandrel 9645

 for the intermediate shaft. Position centring mandrel on the mounting point of the

oil pump and turn the star knob clockwise until it is braced in the crankcase.

Tightening sequence for crankcase

22. Position the remaining 13 M6 x 35 Torx screws on the crankcase. Tighten all screws in the cross

bolt connection to the required torque in accordance with the specified tightening sequence. →
Tightening torque: 9.5 ftlb.

23. Carefully remove any remaining sealant on crankcase (particularly around the oil pan, intermediate-shaft

bearing and crankshaft sealing rings).

24. Fit inner Torx screw with O-ring M9 x 140 for gear carrier -arrow- on crankcase half 4-6. → Tightening

torque: 16 ftlb.

Diagnostic system: reading out fault memory and activating systems

Installing pistons

272