409.03 - Carburetor, Mixture, and Icing. Aero Engines 409.03 - Carburetor, Mixture, and Icing.

Carburetors

Parts of the Carburetor

Carburetors Carburetor is the heart of an engine. The two key functions of the carburetor are: (1) Vaporize the Fuel (2) Mix Fuel and Air 4

Carburetor Mixture Ratios Fuel-Air mixture Running mixture 1:8 Best power mixture 1:14 Chemically correct mixture 1:15 Lowest fuel consumption mixture 1:18 Leanest running mixture 1:20 5 5

Mixture Controls 6 6

Carburetion vs Fuel Injection Advantages: More uniform distribution of fuel to all cylinders Better cooling Better efficiency No carburetor No carburetor icing no need to heat intake air; therefore, more power An alternate air source is required 7 7

Parts of Fuel Injection system 8 8

Fuel Injection Engines Pressurized Fuel Sump Oil and Return Oil From Relief Valve Pressure Oil From Oil Pump Oil Cooler and Filter High Pressure Oil Screen Low Pressure Oil Screen Oil Sump Oil Pump Oil Temperature Gauge Oil Pressure Gauge Oil Pressure Relief Valve Oil Filler Cap and Dipstick TOP VIEW Fuel Boost Pump Fuel Control Unit Fuel Manifold Valve Fuel Discharge Nozzle 9

Carburetor Icing

Carburetor Ice Ice can form in the carburetor and will restrict air flow to the engine, resulting in: Loss of Power Rough Running Engine Total Engine Failure Ice can READILY form in the carburetor in CLEAR AIR with ambient air temperatures from -5 to +30 degrees Celsius, depending on the humidity of the air 11

Dangerous Conditions Serious Icing - cruise or climb power      Serious Icing - cruise or climb power   Moderate Icing - Cruise power or serious icing - glide power   Serious Icing - glide power   Light Icing - glide or cruise power 12

Dangerous Conditions 13 13

Use of Carb-heat and its Effects on Mixture 14 14

Review Exercise