Cylinder Block Assembly: Specifications

Piston and cylinder dimensions

Crankshaft bearing caps, installing
- Bearing -1- is at the toothed belt end; bearing -4- is at the flywheel end.





Tightening sequence
- Stage 1- Tighten all bolts in sequence shown (1-16) to 30 Nm.
- Stage 2- Tighten all bolts in sequence shown (1-16) to 60 Nm.
- Stage 3- Using a fixed wrench, turn all in sequence shown (1-16) 90° further.
- Tighten bolts -A- to 25 Nm.

Axial and radial clearance of crankshaft, measuring
Axial clearance

Note: Do not interchange used bearings.





- Attach dial gauge with universal dial gauge bracket VW 387 to oil pump and bring it into contact with crank web.
- Press crankshaft against dial gauge by hand and set gauge to -O-.
- Press crankshaft away from dial gauge.





- Note reading:

Radial clearance
- Measure radial clearance with Plastigage.





- Read value:

Pistons





Position: arrow on piston crown must always face in direction of travel.
- Mark cylinder number on piston crown with waterproof felt pen.

Note: Do not use a center-punch or similar, as pistons have a special coating.





Checking piston diameter
- Measure pistons approximately 10 mm from bottom of skirt, at 90° to piston pin axis.
^ Difference between actual and nominal diameter: not more than 0.04 mm.








Ring-to-groove clearance








Checking piston ring gap
- Push ring in squarely to a position approximately 15 mm from bottom end of cylinder.

Connecting rods, Connecting rod bearings, checking

Note:
^ Only replace complete sets of conrods
^ Do not interchange connecting rod bearings.





- Before removing, mark positions of connecting rod bearing caps with a felt pen or similar.

Checking radial clearance
- Remove conrod bearing cap. Clean bearing cap and bearing journal.
- Place a length of Plastigage corresponding to width of bearing on the bearing journal or bearing shell.
- Fit Conrod bearing cap and tighten to 20 Nm. Do not rotate crankshaft.
- Remove Conrod bearing cap again.





- Compare width of Plastigage with calibrated scale.
- Fit new Conrod bearing bolts.
- Final Assembly Tightening torque: 30 Nm + 90 (1/4 turn)

Pulley to crankshaft 20 Nm
Central bolt 1) to crankshaft 200 Nm+180° 2)
1) The central bolt must always be replaced.
2) Turning in two stages of 90 is also permissible.