The Briggs and Stratton 351777 Vanguard is a 570 cc, (34.8 cu·in) natural aspirated two-cylinders four-stroke air-cooled internal combustion gasoline engine with a vertical shaft, for general-purpose applications.
Cylinder bore and piston stroke are 72.0 mm (2.83 in) and 70.0 mm (2.75 in), respectively. This engine produced 20.1 PS (14.8 KW; 20.0 HP) at 3,600 rpm of horsepower.
The B&S 351777 features:
- OHV design
- Magneto electronic ignition system
- Float type, side-draft carburetor
- Centrifugal governor
- Full pressure lubrication system with spin-on oil filter
- Forced air cooling system
- Electric starter
General information
Engine Specifications | |
Engine model | 351777 Vanguard |
Engine type | 4-stroke, OHV, V-twin |
Displacement | 570 cm3, (34.8 cu·in) |
Max. horsepower | 20.1 PS (14.8 KW; 20.0 HP) at 3,600 rpm |
Max. torque | – |
Cooling system | Forced air |
Air cleaner | Dual-Clean (paper element with a foam pre-cleaner) |
Lubricating system | Full pressure lubrication with spin-on oil filter |
Ignition system | Magneto electronic |
Fuel system | Float type, side-draft carburetor |
Fuel used | Gasoline |
Starting system | Electric starter |
Governor | Centrifugal governor |
Charging system | Alternator 12V, 16A |
Dimensions (L x W X H) | – |
Dry weight | – |
Cylinder Block and Head
Cylinder block | |
Cylinder bore: | 72.0 mm (2.83 in) |
Piston stroke: | 70.0 mm (2.75 in) |
Cylinder internal diameter (standard): | 72.00-72.030 mm (2.8346-2.8358 in) |
Number of piston rings (compression / oil): | 2/1 |
Connecting rod big end diameter (standard): | 37.060-37.080 mm (1.4591-1.4598 in) |
Connecting rod small end diameter (standard): | 17.090-17.100 mm (0.6728-0.6732 in) |
Piston pin diameter: | 17.070-17.080 mm (0.672-0.6724 in) |
Side clearance (Top): | 0.045-0.076 mm (0.0018-0.003 in) |
Side clearance (Second): | 0.045-0.076 mm (0.0018-0.003 in) |
Side clearance (Oil): | 0.110-0.150 mm (0.0043-0.0059 in) |
Ring end gap (Top): | 0.200-0.400 mm (0.0079-0.0157 in) |
Ring end gap (Second): | 0.200-0.400 mm (0.0079-0.0157 in) |
Ring end gap (Oil): | 0.200-0.400 mm (0.0079-0.0157 in) |
Crankshaft main journal diameter (magneto side): | 29.980-30.000 mm (1.1803-1.1811 in) |
Crankshaft main journal diameter (PTO side): | 34.960-34.970 mm (1.3765-1.3770 in) |
Crankpin journal diameter: | 37.000-37.020 mm (1.4567-1.4575 in) |
Crankshaft center distance: | 35.0 mm (1.38 in) |
Cylinder head | |
Valve arrangement: | OHV, gear driven |
Valves: | 2 (4 valves in total) |
Valve steam diameter (INTAKE): | 5.950-5.960 mm (0.2343-0.2346 in) |
Valve steam diameter (EXHAUST): | 5.940-5.950 mm (0.2339-0.2343 in) |
Camshaft lobe height (INTAKE): | 30.330-30.530 mm (1.1941-1.202 in) |
Camshaft lobe height (EXHAUST): | 30.330-30.530 mm (1.1941-1.202 in) |
Camshaft journal diameter (magneto side): | 15.950-15.970 mm (0.628-0.6287 in) |
Camshaft journal diameter (PTO side): | 19.940-19.960 mm (0.785-0.7858 in) |
Tightening torque
Tightening torque specs | |
Alternator (to cylinder) | 2.0 Nm; 1.5 ft·lb |
Air cleaner base (to carburetor) | 7.0 Nm; 5.2 ft·lb |
Air cleaner support bracket | 7.0 Nm; 5.2 ft·lb |
Alternator | 2.0 Nm; 1.5 ft·lb |
Armature | 3.0 Nm; 2.2 ft·lb |
Blower housings | 7.0 Nm; 5.2 ft·lb |
Back plate | 7.0 Nm; 5.2 ft·lb |
Breather | 3.0 Nm; 2.2 ft·lb |
Carburetor to manifold | 7.0 Nm; 5.2 ft·lb |
Connecting rod | 13.0 Nm; 6.9 ft·lb |
Crankcase cover | 17.0 Nm; 12.6 ft·lb |
Cylinder head | 19.0 Nm; 14.1 ft·lb |
Cylinder shield | 7.0 Nm; 5.2 ft·lb |
Exhaust manifold | 17.0 Nm; 12.6 ft·lb |
Flywheel nut | 175.0 Nm; 129.6 ft·lb |
Fan Retainer | 17.0 Nm; 12.6 ft·lb |
Governor lever nut | 8.0 Nm; 5.9 ft·lb |
Governor control bracket | 16.0 Nm; 11.9 ft·lb |
Intake manifold to cylinder head | 16.0 Nm; 11.9 ft·lb |
Oil pump | 7.0 Nm; 5.2 ft·lb |
Rewind starter (to blower housing) | 7.0 Nm; 5.2 ft·lb |
Rocker arm lock nut | 7.0 Nm; 5.2 ft·lb |
Rocker arm stud | 11.0 Nm; 8.2 ft·lb |
Starter motor | 16.0 Nm; 11.9 ft·lb |
Starter motor thru bolts | 6.0 Nm; 4.4 ft·lb |
Valve cover | 3.0 Nm; 2.2 ft·lb |
Service Data
Valve clearance | |
Intake valve clearance: | 0.10-0.15 mm (0.004-0.006 in) |
Exhaust valve clearance: | 0.10-0.15 mm (0.004-0.006 in) |
Oil system | |
Lubrication system: | Full pressure by gear-driven oil pump |
Oil type: | SF, SG, SH, SJ or higher |
Recommended oil: | Summer: SAE 30W Winter: SAE 5W-20, 5W-30 |
Oil capacity: | 1.65 L (1.74 US. qt, 1.45 Imp. qt.) |
Fuel system | |
Type: | Float type, side-draft carburetor |
Ignition system | |
Type: | Electronic |
Spark plug: | Champion RC12YC |
Spark plug gap: | 0.7-0.8 mm (0.0276-0.0315 in) |
Spark plug torque: | 23 N·m (2.3 kg·m, 17 ft·lb) |
Armature air gap | 0.2-0.3 mm (0.008-0.012 in) |
We try to use official documentation and verify the published data, but errors may occur. In addition, specifications of machinery and equipment may vary depending on markets and modifications. We do not recommend the use of this data for spare parts or repairs. Use official service manuals or parts catalogs for your product.
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