Evolution Engines E7260 - Manual (Page 6)

EN
The electronic ignition requires a 6—7.4V 2500mAh battery. For the best performance,
we recommend a 7.4V 2S Li-Po battery (minimum 2500mAh) and a suitable switch (JRPA001).
A voltage regulator is not required for use with a 7.4V 2S Li-Po battery.
Engine Cooling Requirements
It is very important to consider adequate cooling inside the airplane cowl. Engines require
a cooling airflow exhaust:intake ratio of 3:1 to 5:1. A large open cowl may lead you to believe
there is adequate cooling; however, you must make sure air is flowing through the cowl and
the cylinder head fins. Achieving the proper ratio typically requires cowl and/or engine
baffles to reduce the open intake area.
1. Ensure there is adequate cooling air moving through the cylinder head cooling fins.
The intake air tends to move through the path of least resistance (between the cylinders)
instead of through the cylinder cooling fins.
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.
4. Do not cover the engine exhaust tube with the baffle. The exhaust tube requires direct
air cooling to prevent damage to the exhaust valve.
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
Break-in Fuel Normal Flying Fuel
gasoline:2-stroke oil
32:1 40:1
Engine Break-In Process
A good break-in process is essential to the longevity and performance of your Evolution radial
engine. You can complete the break-in process by either mounting the engine on a test stand
or on an airframe. If you choose to mount the engine on an airframe, remove the cowl during
break-in to ensure adequate cooling.