Skoda Workshop Service and Repair Manuals

Piston and conrod - Summary of components

1 -

Piston

q	check → Fig.

q	mark installation position and matching cylinder

q	arrow on piston crown faces towards the belt pulley side

q	Piston Ø: 76.455 mm (nominal dimension)

2 -	Piston pin

q	if stiff, heat piston to approx. 60°C

q	use drift -T10046- for removing and installing

3 -

Circlip

4 -

Conrod

q	always replace as a set only

q	mark matching cylinder -A-

q	Fitting position: Markings -B- point towards the belt pulley side

q	located axially by pistons

q	separate new conrod → Chapter

5 -	Bearing shell

q	do not mix up used bearing shells (mark)

q	insert bearing shells in the centre

6 -	Cylinder block

q	inspect cylinder bore → Fig.

q	Cylinder Ø: 76.51 mm (nominal dimension)

7 -	Conrod cap

q	as a result of the conrod separated in the cracking process, the cover fits only in one position and only to the relevant conrod

8 -	Conrod bolt, 30 Nm + torque a further + 90° (1/4 turn)

q

replace

q	oil thread and head contact surface

9 -	Oil scraper ring

q	carefully remove and install 3-part oil scraper rings by hand

q	Inspect gap clearance → Fig.

q	End clearance cannot be measured

10 -	Compression rings

q	Offset joint 120°

q	use piston ring pliers for removing and installing

q	marking -TOP- must face towards piston crown

q	Inspect gap clearance → Fig.

q	Inspect end clearance → Fig.

Inspecting piston ring gap clearance –  Push in ring at right angles to the cylinder wall from the top through to the bottom cylinder opening, about 15 mm from the lower cylinder edge.

Piston ring dimensions in mm	new	Wear limit
1. Compression ring	0,20…0,50	1,0
2. Compression ring	0,40…0,60	1,0
Oil scraper ring	0,20…1,10	no wear indication possible

Inspect piston ring end clearance –  Clean annular groove before measurement is taken.

Piston ring dimensions in mm	new	Wear limit
1. Compression ring	0,04…0,08	0,15
2. Compression ring	0,02…0,08	0,15
Oil scraper ring	cannot be measured

Inspecting pistons Special tools and workshop equipment required t  External micrometer 75...100° mm –  Measure about 10 mm from the lower edge, offset at right angles to the piston pin shaft. l  Deviations from specified dimension: max.°0.04 mm

Inspecting cylinder bore Special tools and workshop equipment required t  Internal precision measuring instrument 50...100 mm –  Measure at three points crosswise in a transverse direction -A- and lengthwise -B-. l  Deviations from specified dimension: max.°0.08 mm   Note Do not measure the cylinder bore if the cylinder block is fixed to the assembly stand with the engine mount -MP 1-202-, as this may result in incorrect measurements.