Half thrust rings

Make

Alfa Romeo

Model

145/146 Factory Service Manual

Year

1994–1999

Section

Engine › Half thrust rings

Technical data and maintenanceHalf thrust rings

Half thrust rings

	Unit: mm
Thickness of half thrust rings "a"	2.342 ÷ 2.358
Oversize	0.127
Crankshaft end float	0.059 ÷ 0.221

Engine flywheel

	Unit: mm
Inside diameter of centre bush (bore) "a"	47.010 ÷ 47.035 mm
Heating temperature of ring gear for assembly on flywheel	80° ÷ 100°C

CONNECTING ROD - PISTON ASSEMBLY

Piston

	Unit: mm
Diameter of pistons "a" (1)	Class A - Blue	82.952 ÷ 82.962
	Class B - Pink	82.959 ÷ 82.971
	Class C - Green	82.968 ÷ 82.978
Height of first seal ring seats "b"	1.220 ÷ 1.240
Height of second seal ring seats "c"	1.510 ÷ 1.530
Height of oil scraper ring seats "d"	3.010 ÷ 3.030
Diameter of gudgeon pin holes in pistons "e"	20.002 ÷ 20.007
Clearance between cylinders and pistons	0.038 ÷ 0.062
Difference in weight between pistons	± 5 g
(1) To be measured perpendicular to the gudgeon pin hole at a distance of 12.5 mm from lower edge of skirt.

Connecting rods

	Unit: mm
Diameter of small end bushing bore "a"	20.006 ÷ 20.012
Inside diameter of rod big ends "b"	53.897 ÷ 53.909
Difference in weight between rods	≤ 5 g
Clearance between small end bushings and pins	0.006 ÷ 0.016
Small end end float	0.25 ÷ 0.6

02 Maintenance