Specifications

[P-51D Mustang]
DCS
EAGLE DYNAMICS
41
Figure 23: Oil Dilution Switch
If the engine temperature is high, the engine should be stopped to allow it to cool to an oil
temperature of about 40°C. Then the engine can be started again. The oil should be diluted
immediately as explained above.
Two minutes of oil dilution is sufficient for any ambient temperature down to 10°F. When starting in
temperatures lower than 10°F, heating the engine and oil may be necessary. Dilution duration will
vary in such cases depending on local conditions.
Specifications for the oil system include:
Temperature
Pressure
Minimum
40°С
60 lbs/sq.in.
Desired
70°-80°C
70-80 lbs/sq.in.
Maximum
90°C
90 lbs/sq.in.
Coolant System
With the radiators located in the big air scoop aft of the cockpit under the fuselage, the cooling of the
P-51 engine is quite different from that of most other fighters of the era. The engine is cooled by
liquid in two separate cooling systems. The first system cools the engine proper, the second (called
the after-cooling system) cools the supercharger fuel-air mixture. Each performs a separate function
OIL DILUTION SWITCH