Valve guides

Make

Alfa Romeo

Model

145/146 Factory Service Manual

Year

1994–1999

Section

Engine › Valve guides

Technical data and maintenanceValve guides

Valve guides

	Unit: mm
External diameter of valve guides "a"	13.010 ÷ 13.030 Oversize by 0.20
Internal diameter of valve guides(line-boring) "b"	7.022 ÷ 7.040
Interference between valve guides and corresponding seats	0.033 ÷ 0.080

Valve seats

	Unit: mm
External diameter of valve seats "a"	Intake 35.135 ÷ 35.150 Exhaust 29.142 ÷ 29.157
Contact taper with valves "α"	90° ± 10'
Interference between valve seats and respective seats	Intake 0.121 ÷ 0.146 Exhaust 0.130 ÷ 0.166
Heating temperature of cylinders' head for valve seats fitting	80°C

Valves

	Unit: mm
Diameter of valve stems "a"	Intake 6.975 ÷ 6.990 Exhaust 6.960 ÷ 6.975
Diameter of valve heads "b"	Intake 33.4 ÷ 33.7 Exhaust 27.9 ÷ 28.2
Radial play between valve stems and valve guides	Intake 0.032 ÷ 0.065 Exhaust 0.047 ÷ 0.080

Valve springs

	External Spring	Internal Spring
Free length "L1"	46 mm	39 mm
Length with closed valves "L2"	34 mm	29.5 mm
Load corresponding to "L2"	271 ÷ 294 N (27.6 ÷ 30 kg)	96 ÷ 106 N (9.8 ÷ 10.8 kg)
Length with open valves "L3"	24.5 mm	20 mm
Load corresponding to "L3"	485 ÷ 524 N (49.4 ÷ 53.4 kg)	201 ÷ 221 N (20.5 ÷ 22.5 kg)

Hydraulic tappets

	Unit: mm
External diameter of hydraulic tappets "a"	32.959 ÷ 32.975
Radial play between hydraulic tappets and corresponding seats	0.025 ÷ 0.066

02 Maintenance