Yak 18T - Fuel Specification and Octane Number; Carburettor; Fuel Pressure in Front of Carburettor; Petrol Pump

Yak 18T Flight Operations Manual
Page 13 of 82
Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations
Manuals and has not been approved by the Yakovlev Design Bureau or any other authority.
2.3 Fuel Specification and Octane Number
Petrol B-91/115
Gost 1012-72 (octane number ≥ 91)
2.4 Carburettor
Symbol AK-14P
Type Pressure carburettor, without float
Inlet temperature +10°C - +45°C
2.5 Fuel Pressure in front of Carburettor
At operating conditions 0.2-0.5 kgf/cm²
At minimum rpm at least 0.15 kgf/cm²
2.6 Petrol Pump
Symbol 702 ML
Type Lobe rotary pump
Number per engine 1
2.7 Fine Filter
Symbol 8D 2.966.064
Type Sump, gravity filter
Filtration fineness
36-40μm
2.8 Oil Grade
For flight and winter ops. MC-20 or MK-22 (Gost 10103-49)
2.9 Oil Consumption
At Cruise I (g/l sec/hr) ≤ 8 (during 1
st
overhaul)
2.10 Oil Pressure
At operating conditions 4-6 kgf/cm²
At minimum rpm (in the main line) ≥1 kgf/cm²
(Measured through a special pipe connection at the oil pump)
2.11 Oil Inlet Temperature
Recommended 50°C - 65°C
Minimum permissible 40°C
Maximum during long term operations 75°C
Maximum temperature in first 15mins operation 85°C
2.12 Cylinder Head Temperature
Recommended 140°C - 190°C
Minimum permissible for engine normal operation 120°C
Minimum for continuous operation 140°C
Maximum for continuous operation 220°C
2.13 Magnetos
Symbol M9-25M
Type Four-spark, shielded
Number in the engine 2
2.14 Spark Plugs
Symbol CD-49CMM
Number per cylinder 2
Ignition sequence 1-3-5-7-9-2-4-6-8