Removing Pistons

CAUTION: Ingress of dirt

Danger of material damage due to blocked oil bores/oil ducts.

→ 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

Fix the gear carrier for removing the pistons with two auxiliary screws to crankcase half 1-3.

Information

Mark pistons in installation position before removal. Combustion residues (carbon deposits) can be removed with a brass brush.
Hard to remove residues can be removed in the ultrasound bath following disassembly.

Unscrew internal Torx screws with O-ring (M9 x 94 inside and M9 x 84 outside) for the bearing case -arrows- on crankcase half 1-3.

Fig 1: Locating Additional Screws For Bearing Case, Side 1-3
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
Unscrew internal Torx screw with O-ring (M9 x 140) for the bearing case -arrow- on crankcase half 4-6.

Fig 2: Locating Bearing Case Screw, Side 4-6
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Turn crankcase at assembly support until crankcase half 4-6 stands vertically upwards.
Unscrew four coated Torx screws (M6 x 35) -1- on crankcase half 4-6 on the flywheel side. Replace screws during assembly.

Fig 3: Locating Coated Screws For Cross Bolt Connection
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Unscrew 20 remaining M6 x 35 Torx screws in the crankcase cross bolt connection.
Unscrew the star screw that secures crankcase half 4-6 to the engine support -arrow- .

Fig 4: Locating Mount For Crankcase Half 4-6 On Engine Support
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Tap the crankcase halves gently with a plastic hammer. Carefully lever the various cast lugs with a screwdriver to separate the crankcase halves from one another.

Fig 5: Separating Crankcase Half
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
NOTE:
Crankcase half 4-6 incorrectly levered off
- Risk of damage to pistons and piston rings
→ Lever off crankcase half 4-6 only with the help of a second person.
Carefully lever off crankcase half 4-6 with the help of a second person to avoid damaging the pistons (e.g. by tilting). Remove old shaft sealing rings.

Fig 6: Levering Off Crankcase Half 4-6
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
For the following steps, fasten the bearing case to crankcase housing half 1-3 with two cylinder-head screws using spacer sleeves 9613 . → Tightening torque: 20 Nm (15 ftlb.)

Fig 7: Locating Auxiliary Screws For Securing Bearing Case
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Removing pistons, side 4-6
Lever off the front piston-pin circlips of marked pistons 4-6 (from the viewpoint of the drive belt side) using a small screwdriver, push out the piston pin -arrow- and remove the pistons one by one. Assign the piston pins to the appropriate pistons again.

Fig 8: Removing Piston Pins
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Removing pistons and connecting rods, side 1-3
Remove marked pistons 1-3, including connecting rods. To do this, turn the crankshaft on the pulley until the respective connecting rod bearing cover stands upwards. Undo and remove the connecting rod bolts (twelve-edged socket-wrench insert a/f 14), remove connecting rod bearing cap.

Fig 9: Identifying Rod Bolts
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Information
- Join connecting rod and connecting rod bearing cap together again immediately after removal.
- Connecting rod bolts must be replaced.
Carefully press connecting rod and pistons downwards out of crankcase half 1-3 using a shop-made plastic mandrel. Allocate a connecting rod cap immediately to the relevant connecting rod and screw on loosely. Pay attention to the bearing shells.

Fig 10: Removing Connecting Rod Using Plastic Mandrel (Shop-Made)
Courtesy of PORSCHE CARS NORTH AMERICA, INC.
Unscrew pulley fastening screw and remove washer.
To remove connecting rod 4-6, remove the bearing case; see → 134819 REMOVING AND INSTALLING CRANKSHAFT .