Valves

Make

Alfa Romeo

Model

145/146 Factory Service Manual

Year

1994–1999

Section

Engine › Valves

Technical data and maintenanceValves

Valves

	Unit: mm
Diameter of valve stems "a"	Intake	6.965 ÷ 6.980
	Exhaust
Diameter of valve mushrooms "b"	Intake	31.8 ÷ 32.0
	Exhaust	25.8 ÷ 26.0
Valve mushroom angle "α"	Intake	44°25' ÷ 44°35'
	Exhaust
Radial play between valve stems and valve guides	Intake	0.02 ÷ 0.05
	Exhaust

Valve springs

Outer spring		Inner spring
Free length "L1"	~ 51.8 mm	~ 38 mm
Length with valves closed "L2"	32.5 mm	30.5 mm
Load corresponding to "L2"	21.4 ÷ 22.6 kg	13.6 ÷ 14.4 kg
Length with valves open "L3"	22.9 mm	20.9 mm
Corresponding load at "L3"	35.52 ÷ 35.72 kg	31.89 ÷ 33.69 kg

Camshafts

Unit: mm
Diameter of camshaft journals "a"	26.959 ÷ 26.980
Maximum cam lift	Intake	9.50
	Exhaust	9.40
Clearence between camshaft journals and their housings	0.020 ÷ 0.074

Hydraulic tappets

Unit: mm
Outside diameter of hydraulic tappets "a"	32.959 ÷ 32.975
Clearence between cup and housing	0.025 ÷ 30.066

ANGLES OF ACTUAL TIMING DIAGRAM

Intake	Opens (before T.D.C.)	a 20°
	Closes (after B.D.C.)	b 49°
Exhaust	Opens (before B.D.C.)	c 52°
	Closes (after T.D.C.)	d' 22°

a’ 10°
b’ 49°
c’ 42°
d 12°

02 Maintenance