Service manual

181 CID (3.0L) 4 CYLINDER GM ENGINE
SERVICE MANUAL NUMBER 26
90-861329--1 MARCH 1999 Page 3A-7
Cylinder Head
Gasket Surface Flatness
.003-.008 in any 6 in. (152) or .007
(0.15) Overall Max
Valve System
Lifter Hydraulic
Rocker Arm Ratio 1.75 to 1
Collapsed Tappet Gap 3/4 Turn Down from Zero Lash
Intake 45°
Face Angle
Exhaust 45°
Seat Angle (Intake & Exhaust) 46°
Seat Runout (Intake & Exhaust) .002 (0.05) Max
Intake 1/16 (.0625 in.) (1.16 mm)
Seat Width
Exhaust 1/16-5/64 [.0625-.07812 in.] (1.6-2.0 mm)
Intake .0010-.0027 (0.025-0.069)
Stem
Production
Exhaust .0007-.0027 (0.018-0.069)
Stem
Clearance
Intake .003 (0.09) Max
Service
Exhaust .004 (0.11) Max
Free Length 2-1/16 in. (52 mm)
Valve
Closed
100-110 lb. (136-149 N) at 1-19/32 in. (41 mm)
Spring
Pressure
Valve
Open
208-220 lb. (282-300 N) at 1-7/32 in. (31 mm)
Installed
±
Intake
Height ±
.031(8)
Exhaust
(1/32) 1.6562 (42)
Internal Damper None
General
Some of the repairs in this section must be completed with engine removed from boat.
Engine removal depends upon type of repair and boat design. Place engine on repair stand
for major repairs.
When engine removal is not required, make certain that battery cables are disconnected
at the battery prior to performing any on-board engine repair procedure.
Lubricate all moving parts (during reassembly) with engine oil. Apply Quicksilver Perfect
Seal on threads of and under heads of cylinder head bolts, and on threads of all cylinder
block external bolts, screws and studs.
Model No. of Cylinders cu-in./liters Displacement
MCM 3.0L 4 181 (3L)
Index