Propeller Selection; Fuel Selection - Horizon Hobby Evolution Radial Glow E777 Manuel D'instructions

2. If necessary, add baffles to the engine to prevent air from moving between the cylinders.
Engine baffles force cool air through the cooling fins and greatly reduce the intake area
in the front of the cowl.
3. Add cooling baffles to the engine cowl between the top of the cylinder heads and the inside
of the cowl. Do not cover the engine exhaust pipe with the baffles. This needs cool air over
it to prevent exhaust valve damage.

Propeller Selection

Propeller selection is critical for proper engine operation. You can find recommended propel-
lers and operating RPM ranges in the specification chart. Evolution radial engines have a lower
operating RPM range and greater torque within that range that require more blade pitch and
increased in-air pitch speed for your airplane.
To increase climbing and acceleration: Increase propeller diameter and decrease blade pitch.
To increase top speed: Decrease propeller diameter and increase blade pitch.
Make sure the propeller is securely mounted to the crankshaft before attempting to start
the engine.
1. Remove the wire circlip from the crankshaft in front of the propeller nut.
2. Install the propeller on the crankshaft.
3. Secure the propeller with the hexagonal nut.
4. Securely fasten the circlip on the outside of the hexagonal nut.
WARNING: NEVER start the engine without the circlip securely fastened. Doing so may
result in serious injury, as the propeller may become loose once the engine is started.

Fuel Selection

Evolution radial engines only require 6–7% synthetic oil after the break-in process. There is no
need to use fuel with nitro content higher than 10%. Adding additional oil to the fuel will reduce
the engine RPM. Please refer to the following chart for fuel recommendations.
Depending upon your choice of oil, you may find that the engine feels 'dry' at the end of a flight
when using 6–7% oil. If you want, you can use 8–9% oil with any mix of flying fuel.
Tip: Many users combine one gallon of a good quality 15% nitro fuel (with 18% oil content)
with a gallon of pure methanol to achieve a 7 1/2% nitro and 9% oil mixture.
break-in
1st hour
2 to 3 hours
flying without nitro
1st hour
2 to 3 hours
flying with nitro
1st hour
2 to 3 hours
methanol %
90%
92%
93%
94%
88%
83%
synthectic oil %
10%
8%
7%
6%
7%
7%
nitro %
0%
0%
0%
0%
5%
10%
7
EN