Cylinder Head Assembly: Specifications

Cylinder Head and Valve Train
Cylinder head flatness 25 microns
Cylinder head gasket surface finish 10 microns
Combustion chamber volume 53 ± 0.5 cc (3.2342 ± 0.0305 ci)
Valve arrangement (front to rear)
LH E-I-E-I-E-I-E-I
RH I-E-I-E-I-E-I-E
Valve guide bore diameter 7.044 - 7.015 mm (0.2773 - 0.2762 in.)
Valve stem diameter
Intake 6.995 - 6.975 mm (0.2753 - 0.2746 in.)
Exhaust 6.970 - 6.949 mm (0.2744 - 0.2735 in.)
Valve stem-to-guide clearance
Intake 0.069 - 0.020 mm (0.0027 - 0.0007 in.)
Exhaust 0.095 - 0.046 mm (0.0037 - 0.0018 in.)
Valve head diameter
Intake 44.5 mm (1.7519 in.)
Exhaust 34.0 mm (1.3385 in.)
Valve face runout limit 0.05 mm (0.0019)
Valve face angle 45.5 degrees
Valve seat width
Intake 2.1 - 1.9 mm (0.0827 - 0.0748 in.)
Exhaust 2.1 - 1.9 mm (0.0827 - 0.0748 in.)
Valve seat runout (TIR) 0.025 mm (0.0009 in.)
Valve seat angle 45.00 degrees
Valve spring
Free length
Intake 50.2 mm (1.9763 in.)
Exhaust 50.2 mm (1.9763 in.)
Out-of-square limit
Intake 2.5 degrees
Exhaust 2.5 degrees
Compression pressure
Intake 633.3 - 701.3 N @ 28.02 mm (1.1031 in.)
Exhaust 633.3 - 701.3 N @ 28.02 mm (1.1031 in.)
Installed height
Intake 40.6 - 43.6 mm
Exhaust 40.6 - 43.6 mm
Installed pressure
Intake 272.1 - 306.1 N @ 40.0 mm (1.5748 in.)
Exhaust 272.1 - 306.1 N @ 40.0 mm (1.5748 in.)
Installed pressure service limit
Intake 274.6 N @ 40.01 mm (1.5752 in.)
Exhaust 274.6 N @ 40 - 01 mm (1.5752 in.)
Roller follower ratio 1.75:1

For torque specifications, refer to the service procedure.