Technical data

20B TWO AND 30B THREE ENGINE SERVICE SPECIFICATIONS
NOTE: All dimensions and specifications contained in this section are given in inches then
millimeters unless otherwise stated. For example, 0.002 (0.5 mm).
Cylinder Compression Pressure
Difference Between
Cylinders (maximum)
Fuel Injection Order
20BTwo
30B Three
Specified Value/Standard
398.16 psi (at 280 rpm)
(28
kg/cm~
35.55 psi
(2.5
kg/cm~
1 - 2
1-3-2
Injection Timing at BTDC on Compression Stroke
Spill
timing (static)
Cylinder Head
Bottom surface distortion
Valve guide 1.0. (IN & EX)
Valve seat angle (IN & EX)
Valve seat width (I N & EX)
Valve seat sinkage
Valve Clearance (IN and EX)
15
19° ±1.5
Within 0.002
(0.05 mm)
0.260
(6.6 mm)
45°
0.051 - 0.071
(1.3 -1.8 mm)
0.010 (cold)
0.25
Repair Limit
355.5 psi
(25 kg/cm
2
)
0.004
(0.1 mm)
0.098
(2.5 mm)
-0.039 (Service limit)
(-1 mm)
Westerbeke Engines