1. 409.03 - Carburetor, Mixture, and Icing.
Aero Engines
Carburetor, Mixture, and Icing.

2. Carburetors

3. Parts of the Carburetor

4. 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

5. 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

6. Mixture Controls 6 6

7. 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

8. Parts of Fuel Injection system8 8

9. 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

10. Carburetor Icing

11. 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

12. 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

13. Dangerous Conditions 13 13

14. Use of Carb-heat and its Effects on Mixture14 14

15. Review Exercise