Mercury 305 CID - Page 201

ENGINES - 3A-990-823225--1 1096
5.0L / 305 CID / 5.7L / 350 CID Engine Specifications (Does Not Include Gen +)
Unit Of Measurement
In. (mm)
VALVE SYSTEM
ENGINE 5.0L / 305 CID 5.7L / 350 CID
Lifter Type (NOTE 1) Flat Hydraulic
Lifter Type (NOTE 1) Roller Hydraulic
Rocker Arm Ratio 1.50 to 1
Valve Lift
Intake .394 (10.00)
Valve
Lift
Exhaust .404 (10.26)
Valve Lash (Intake and Exhaust) 1 Turn Down from Zero Lash
Face Angle
Intake 45°
Face
Angle
Exhaust 45°
Seat Angle (Intake & Exhaust) 46°
Seat Runout (Intake & Exhaust) .002 (0.05) Max
Seat Width
Intake .03215-.0625 (0.79-1.58)
Seat
Width
Exhaust .0625-.09375 (1.58-2.38)
S
Production
Intake .0010-.0027 (0.025-0.069)
Stem
Cl
Production
Exhaust .0010-.0027 (0.025-0.069)
Clearance
Service
Intake .0037 (0.09) Max
Service
Exhaust .0047 (0.11) Max
Stem Diameter
Intake .341 (8.66)
Stem
Diameter
Exhaust .372 (9.45)
Valve Diameter
Intake 1.84 (46.74) 1.94 (49.28)
Valve
Diameter
Exhaust 1.50 (38.1)
Valve Margin Intake and Exhaust .0312 (0.79)