Combination Octane Rating Unit Engine for Petroleum Testing Equipment

The Combination Octane Rating Unit is designed to determine the knock rating of liquid spark-ignition engine fuels in terms of Research Octane Number (RON) and Motor Octane Number (MON). It is suitable for testing fuels containing up to 25% ethanol by volume.

The unit uses a standardized single-cylinder, four-stroke, carbureted engine with a variable compression ratio. It operates under defined conditions to evaluate fuel knock characteristics according to established test methods.

The dual-speed motor enables convenient conversion between RON and MON testing without changing the flywheel. The motor-driven cylinder adjustment system allows precise compression ratio control, while the digital operating panel displays compression ratio, ignition timing, and barometric pressure-compensated readings.

Digital knock signal adjustment, intake air humidity control, an exhaust surge tank, and an automatic safety shutdown system support consistent testing and reliable operation.

Manufactured by Atico Export for reliable octane rating determination and fuel quality evaluation in petroleum testing laboratories.

• Determination of Research Octane Number (RON)
• Determination of Motor Octane Number (MON)
• Testing of spark-ignition engine fuels
• Evaluation of gasoline containing up to 25% ethanol by volume
• Fuel quality control and knock resistance assessment
• Laboratory testing of primary reference fuels

Working Range :

• Up to 120 octane number

Cylinder Jacket Coolant Temperature :

• 100 ± 1.5°C (212 ± 3°F)

Crankcase Oil Temperature :

• 57 ± 8.5°C (135 ± 15°F)

Motor Octane Number (MON) Conditions :

• Engine speed: 900 ± 9 RPM
• Ignition timing: Variable according to cylinder height
• Intake air temperature: 38 ± 1°C (100 ± 5°F)
• Intake mixture temperature: 149 ± 1°C (300 ± 2°F)

Research Octane Number (RON) Conditions :

• Engine speed: 600 ± 6 RPM
• Ignition timing: 13° BTDC
• Intake air temperature: 52 ± 1°C (125 ± 2°F)

Engine Specifications :

Compression Ratio :

• 4:1 to 18:1

Cylinder Bore Diameter :

• 82.55 mm (3.250 inches)

Stroke :

• 114.30 mm (4.50 inches)

Carburetor Venturi (Research) :

• 14.30 mm (9/16 inch)

Intake Valve Clearance (Hot) :

• 0.20 ± 0.025 mm (0.008 ± 0.001 inches)

Exhaust Valve Clearance :

• 0.20 ± 0.025 mm (0.008 ± 0.001 inches)

Intake Valve Opening Timing :

• 10° ± 2.5° ATDC

Intake Valve Closing Timing :

• 34° ABDC

Exhaust Valve Opening Timing :

• 40° BBDC

Exhaust Valve Closing Timing :

• 15° ± 2.5° ATDC

Crankcase Oil Pressure :

• 172 to 207 kPa (25 to 30 psi)

Compression Ratio Adjustment :

• Motor-driven

Compression Ratio Display :

• Dial indicator and digital counter

Engine Speed Conversion :

• Dual-speed motor

Carburetor :

• Four-bowl falling-level type with cooling function

Ignition Timing Display :

• Digital with automatic setting

Crankcase Pressure Display :

• Provided

Crankcase Oil Heater :

• Provided

Oil Temperature Display :

• Provided

Air Humidity Control Apparatus :

• Provided

Unit Protection System :

• Provided

Dimensions (L × W × H) :

• 68 × 42 × 58 inches (172.72 × 106.68 × 147.32 cm)

Net Weight :

• 1022 kg (2250 lbs)

• No flywheel change required when switching test methods
• Motor-driven compression ratio adjustment
• High-strength and rigid engine crankcase
• Dial indicator and digital counter for compression ratio measurement
• Digital display of ignition timing and compression ratio
• Automatic setting functions for simplified operation
• Digital knock signal adjustment for stable signal measurement
• Automatic engine shutdown with fault indications
• Exhaust surge tank to reduce resonance pulses and back pressure
• Intake air humidity control according to applicable ASTM requirements
• Four-bowl falling-level carburetor with cooling function
• Crankcase oil heater and oil temperature display
• Crankcase pressure display
• Integrated unit protection system
• Operating panel with protective functions and push-button controls