Briggs and Stratton 303447

Briggs and Stratton 303447The Briggs and Stratton 303447 Vanguard is a 495 cc (30.2 cu·in) V-twin air-cooled four-stroke internal combustion gasoline engine, manufactured by Briggs and Stratton.

The B&S 303447 engine has an OHV (over-head valve) design and a horizontal PTO shaft. This engine is equipped with float type, down-draft carburetor and an magneto electronic ignition system. The B&S 303447 engine used low profile dual-clean air cleaner.

The cylinder bore is 68.0 mm (2.68 in) and the piston stroke is 66.0 mm (2.6 in). The compression ratio rating is 8.2:1.

This engine produced 16.2 PS (11.9 kW; 16.0 HP) at 3,600 rpm of horsepower.

The breakdown of the engine code is as follows:

  • 30 – Displacement
  • 3 – Basic design series
  • 4 – Horizontal PTO-shaft
  • 4 – Ball bearing, flange mounting, pressure lubrication
  • 7 – Electric starter

General information

Engine Specifications
Model B&S 303447 Vanguard
Type 4-stroke, L-head, V-twin
Displacement 495 cm 3 (30.2 cu-in)
Max. horsepower 16.2 PS (11.9 kW; 16.0 HP) at 3,600 rpm
Max. torque
Fuel system Float type, down-draft carburetor
Cooling system Forced-air
Ignition system Electronic
Lubricating system Full pressure lubrication with spin-on oil filter
Starting system Electric starter
Fuel used Gasoline
Fuel tank capacity

Cylinder Block and Head

Cylinder block
Compression ratio: 8.2:1
Bore x Stroke 68.0 mm X 66.0 mm (2.68 x 2.60 in)
Sleeve internal diameter 68.000-68.030 mm (2.6772-2.6783 in)
Number of piston rings (compression / oil): 2 / 1
Side clearance Top 0.045-0.076 mm (0.0018-0.003 in)
Second 0.045-0.076 mm (0.0018-0.003 in)
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)
Second 0.200-0.400 mm (0.0079-0.0157 in)
Oil 0.200-0.400 mm (0.0079-0.0157 in)
Connecting rod small end ID 17.090-17.100 mm (0.6728-0.6732 in)
Piston pin outer diameter 17.070-17.080 mm (0.672-0.6724 in)
Cylinder Head
Valve Arrangement: OHV
Valves: 4 (2 per cylinder)
Valve steam diameter INTAKE 5.950-5.960 mm (0.2343-0.2346 in)
EXHAUST 5.940-5.950 mm (0.2339-0.2343 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 Information

Engine
Max speed 3,600 rpm
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
Oil type API SF, SG, SH, SJ or higher
Recommended oil Summer: SAE 30, 10W-30
Winter: SAE 5W-30
Oil capacity (with filter) 1.65 L (1.74 US. qt, 1.45 Imp. qt.)
Ignition system
Spark plug Champion RC12YC
Spark plug gap 0.7-0.8 mm (0.0276-0.0315 in)
Author: Sergei Wers
About: Co-founder and CEO of a multi-brand auto repair shop (engine repair, chassis repair, body repair and painting) for over 15 years. I have been developing internet sites with technical specifications for more than seven years.

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1 Comment

  1. Well, back to the start for this page!

    Under Gemeral Information:
    ModelB&S 303447 Vanguard Type 4-stroke, L-head, V-twin

    Under Cylinder Block and Head:
    Valve Arrangement:OHV

    Well, simple observation tells the tale. It’s OHV.

    Why go to all this time and trouble to have pages of info that are you know, kind of questionable?

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