Installing Pistons

→ Absolute cleanliness is essential when working on the engine.

→ Lay removed engine parts on a clean base and make sure to cover them.

→ Use the cover for dust protection when fitting the engine NR.165  on the engine assembly support.

Information 

• If the piston, piston pin or piston-pin circlip are incorrectly assembled, the corresponding piston can be pulled out of the cylinder as follows. Degrease center of piston crown with acetone. Coat suitable plastic mandrel with instant adhesive, allow adhesive to cure, pull out piston, remove plastic mandrel immediately. 

Information 

• All O-rings and seals (shaft seals), micro-encapsulated, coated screws or lock nuts must be replaced. 

Information 

• Replace M9 x 1.25 connecting rod bolts and the piston-pin circlips that have been removed. 

Information 

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

Piston/connecting rod assembly, cylinder 1-3: 

1. Install bearing case in crankcase half 1-3. → Subsequent Work 
2. Fit pulley with a fastening screw. Turn the crankcase at the assembly support so that cylinders 1, 2 and 3 stand vertically upwards.
3. Turn crankshaft on pulley until the connecting-rod bearing from cylinder 1 stands vertically upwards. In doing so, the bore marked 'U4'  can be fixed with the bore in the crankcase using the fixing pin 9595/1  .

   Information 

   • Observe information on aligning piston ring gaps at all times. 
4. Prepare pre-assembled piston/connecting rod unit of cylinder 1  for installation. To do this, clamp the connecting rod to a vice with aluminum jaws, for example. Align the gaps in the piston rings as follows:
   1. 4.1. Align the second groove on the piston ring with the twist lock -arrow-  .
      Fig 1: Locating Twist Lock Of Piston Ring, Second Groove

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   2. 4.2. Turn gap of piston ring, groove 1, through 180°.
   3. 4.3. Turn the gaps of the oil scraper ring so that the gaps are located at the oil piston shank area. When doing so, the gaps of both rings and the springs should not be on top of one another (they should be slightly offset with respect to one another).
5. Coat piston and piston rings with plenty of new engine oil.
6. Insert connecting rod bearing in connecting rod and connecting rod cap. Coat sliding surface with Optimol Optipit (available from Porsche Parts Service: 000.043.204.17).
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.
   Fig 2: Positioning Clamping Tool On Universal Piston Ring Restraining Strap

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8. Coat cylinder bores 1-3 with plenty of new engine oil.
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.
   Fig 3: Installing Piston In Cylinder Bore

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10. Check direction of assembly: arrow on piston crown always points to flywheel side 
    Fig 4: Locating Piston Installation Position In Crankcase

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    NOTE: Incorrect handling of components

    • Risk of damage to components

    → Carefully fit or remove the component.

11. Hold the piston ring restraining strap firmly and press piston in a cable into the cylinder bore using a plastic mandrel.
    Fig 5: Pressing Piston Into Cylinder Bore

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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.
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
    Fig 6: Identifying Connecting Rod Bolts

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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: 20 Nm (15 ftlb.)  ; → Torque angle, final tightening: 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 pulley; 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
    • Drei Bond 1209 (optional)
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.
    Fig 7: Aligning Timing Chain And Connecting Rod

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18. Apply sealant to the sealing face of crankcase half 4-6.
    Fig 8: Identifying Application Of Sealant And Tightening Sequence For Crankcase

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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.
20. Fit four new, coated Torx screws (M6 x 35) -1-  on the flywheel side.
    Fig 9: Identifying Coated Screws For Cross Bolt Connection

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21. Position seven Torx screws (M6 x 35) on the pulley side -1-  ; then fit special tool centering mandrel 9645  for the intermediate shaft. Position centering mandrel on the mounting point of the oil pump and turn the star knob clockwise until it is braced in the crankcase.
    Fig 10: Identifying Cross Bolt Connection On Belt Side

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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: 13 Nm (9.5 ftlb.) 
    Fig 11: Identifying Crankcase Screws Tightening Sequence

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23. Carefully remove any remaining sealant on crankcase (particularly around the oil pan, intermediate-shaft bearing and crankshaft sealing rings).
24. Fit internal Torx screw with a new O-ring (M9 x 140) for bearing case -arrow-  on crankcase half 4-6. → Tightening torque: 22 Nm (16 ftlb.) 
    Fig 12: Locating Additional Screw For Bearing Case, Side 4-6

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25. Tighten third star screw for crankcase half 4-6 on engine support.
    Fig 13: Locating Mount For Crankcase Half 4-6 On Engine Support

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26. Remove pulley.
27. Fit crankshaft sealing ring on pulley side → Installing Crankshaft Sealing Ring - Belt Pulley Side  .
28. Only position pulley with fastening screw (to turn the crankshaft).
29. Check the position of the crankshaft using the measuring mandrel 9699/1  .
    Fig 14: Measuring Mandrel 9699/1

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30. Fit crankshaft sealing ring on flywheel side. Use insertion device 9699  for fitting. → Installing Crankshaft Sealing Ring - Flywheel Side  .

    Piston assembly, cylinder side 4-6: 

31. Turn the crankcase at the assembly support so that cylinder bank 4-6 stands upwards.
32. Move crankshaft of cylinder 6 to TDC by turning it on the pulley (in a clockwise direction). Bore U6  on the pulley must be aligned with the fixing bore on the crankcase. Fix the crankshaft using a fixing pin 9595/1  .
33. Engine M96/25 2.7l:  Fasten special tool centering aid 9602/4  to crankcase using two countersunk screws.
    Fig 15: Identifying Guide For Piston Pin Assembly In 2.7L

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34. Engine M96/26 3.2l:  Fasten special tool centering aid 9602/2  to crankcase using two countersunk screws.
    Fig 16: Identifying Guide For Piston Pin Assembly In 3.2L

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    Information 

    • Observe information on aligning piston ring gaps at all times. 
35. Prepare pistons for installation in the same way as cylinder bank 1-3 (piston rings, oiling, piston ring tensioning clamp).

    Information 

    • Leave the centering mandrel in the eye of the connecting rod until the relevant piston (4-6) contacts the centering mandrel during assembly  .
36. Align connecting rod using the centering mandrel 9608  as required.
    Fig 17: Aligning Connecting Rod

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37. Coat cylinder bore with new engine oil. Place piston 6 on cylinder bore 6 using universal piston ring restraining strap, 75-125 mm Nr.55  .
    Fig 18: Placing Piston In Cylinder Bore

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38. Check direction of assembly: arrow on piston crown always points to flywheel side 
    Fig 19: Locating Piston Installation Position In Crankcase

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    NOTE: Incorrect handling of components

    • Risk of damage to components

    → Carefully fit or remove the component.

39. Hold the piston ring restraining strap firmly and press piston into a cable into the cylinder bore using a plastic mandrel until the piston touches the centering mandrel.
    Fig 20: Pressing Piston Into Cylinder Bore

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40. 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.
41. Align piston and connecting rod again using the centering mandrel 9608  before fitting the piston pins.
    Fig 21: Aligning Piston Connecting Rod Using Centering Mandrel

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42. Insert piston-pin circlip into the assembly tube of the special tool assembly tool 9602/1  . Insert the lug of the circlip so that it is aligned to the right in the groove.
    Fig 22: Inserting Piston-Pin Circlip Into Assembly Tube

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43. Insert pressure pin -1-  carefully into assembly tube -2-  , ensuring that the circlip does not pop out.
    Fig 23: Identifying Pressure Pin In Assembly Tool

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44. Oil piston pin -3-  with new engine oil and place it in an upright position on a clean surface on the workbench. Position assembly tube with circlip -1-  and pressure pin on piston pin.
    Fig 24: Positioning Assembly Tool On Piston Pin

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45. Press piston-pin circlip with pressure pin -1-  onto the piston pin; while doing so, press assembly tube -2-  firmly onto the piston pin. This will move the piston-pin circlip into the correct installation position.
    Fig 25: Moving Piston-Pin Circlip Into Installation Position

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46. Check installation position of piston-pin circlip in assembly tube.
    Fig 26: Installation Position Of Piston-Pin Circlip In Assembly Tube

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47. Assembly tool 9602/1  with piston pin circlip and piston pin must be inserted through the centering aid 9602/5  into the crankcase. Press piston pin into assembly bore of piston/connecting rod eye.
    Fig 27: Identifying Piston Pin And Circlip On Assembly Tool 9602/1

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48. Groove in assembly tube must be seated on dowel pin of centering aid 9602/5.
    Fig 28: Identifying Position Of Assembly Tube On Centering Aid 9602/5

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49. Push the piston pin circlip to its installation position by briefly and forcefully striking the palm of your hand against the star knob of the pressure pin.
    Fig 29: Inserting Piston-Pin Circlip In Cylinder 6

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50. Using a mirror, check that the piston-pin circlip is seated correctly.
    Fig 30: Checking Seating Of Piston-Pin Circlip

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    NOTE: Incorrect handling of components

    • Risk of damage to components

    → Carefully fit or remove the component.

51. Repeat steps  35- 49 carefully to assemble pistons 5 and 4. During this process, the crankshaft is fixed to the pulley on the crankcase through bore U5  for cylinder 5 and through bore U4  for cylinder 4. Convert the assembly tool 9602/1  as described below.
52. Slide a spacer sleeve onto the assembly tube for the assembly of pistons pins and circlip on cylinder 5.
    Fig 31: Identifying Spacer Sleeve For Cylinder 5

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53. Fit the piston-pin circlip for cylinder 5 using a sleeve.
    Fig 32: Inserting Piston-Pin Circlip For Cylinder 5

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54. Slide two spacer sleeve onto the assembly tube for the assembly of pistons pins and circlip on cylinder 4.
    Fig 33: Identifying Spacer Sleeves For Cylinder 4

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55. Fit the piston-pin circlip for cylinder 4 using two sleeves.
    Fig 34: Inserting Piston-Pin Circlip In Cylinder 4

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56. Once the pistons have been installed, seal the bore for the piston pin and circlip assembly on the crankcase using the aluminum screw plug and new sealing ring. → Tightening torque: 80 Nm (59 ftlb.) 
    Fig 35: Locating Screw Plug For Assembly Bore In Crankcase

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