Seal rings

Make

Alfa Romeo

Model

145/146 Factory Service Manual

Year

1994–1999

Section

Engine › Seal rings

Technical data and maintenanceSeal rings

Seal rings

Ring thickness "a"	First ring	1.470 ÷ 1.490
	Oversize 0.1
	Second ring	1.475 ÷ 1.490
Oversize 0.1
Scraper ring	2.975 ÷ 2.990
Oversize 0.1
Ring gap "b" (1)	First ring	0.25 ÷ 0.50
Second ring	0.30 ÷ 0.50
Scraper ring	0.25 ÷ 0.50
End float between rings and their seats	First ring	0.030 ÷ 0.070
Second ring	0.020 ÷ 0.055
Scraper ring	0.020 ÷ 0.055
(1) To be measured in the checking nut or in the cylinder

Gudgeon pins

Outside diameter of gudgeon pins "a"	19.996 ÷ 20.000
Clearance between gudgeon pins and their housings on pistons	0.002 ÷ 0.011

CYLINDER HEADS

Head

Valve guide seat diameter "a"	12.950 ÷ 12.977
Valve guide protrusion "b"	11.25 ÷ 11.75
Valve cup seat diameter "c"	33.000 ÷ 33.025
Valve seat housing diameter "d"	Intake: 31.519 ÷ 31.544	Exhaust: 27.021 ÷ 27.042
Combustion chamber minimum depth "e"	13 ± 0.2
Maximum flatness error of lower head surface	0.1
Diameter of camshaft bearings "f"	26.045 ÷ 26.070
Diameter of timing variator support "g"	55.990 ÷ 56.015

Valve guides

Outside diameter of valve guides "a"	13.010 ÷ 13.030
Oversize 0.20
Inside diameter of guide valves (bore) "b"	7.022 ÷ 7.040
Interference between valve guides and their housings	0.033 ÷ 0.080

02 Maintenance