Cooperative Fuel Research (CFR) Engine

Preliminary Checklist

 * 1) Check Engine Oil Level
 * 2) Check Coolant Level
 * 3) Open Coolant Valve for Pressure Transducer
 * 4) Input Desired Fuel
 * 5) Check Compression Ratio
 * 6) Micrometer Reading
 * 7) CR=(4.5/(Reading+0.5))+1
 * 8) Double Check The Head Is Securely Tightened
 * 9) Check The Valve Clearances
 * 10) Exhaust:  0.010”
 * 11) Intake:     0.008”
 * 12) Set Timing For Current Compression Ratio
 * 13) Compression Ratio
 * 14) Spark Advance BTDC
 * 15) Connect Ignition Wires to 12V Battery
 * 16) Turn On Circuit Breaker to Engine
 * 17) Turn On Lab Exhaust Fan

Operational Checklist

 * 1) Open Exhaust Gate Valve
 * 2) Engage Starting Motor
 * 3) Turn On Ignition Switch
 * 4) Turn Throttle to Wide Open Position
 * 5) Back Out Fuel Needle Valve, Adjust Until Backfiring Stops
 * 6) Let Engine Warm Up, Readjust Fuel Needle Valve as Needed

Test Run Preparation

 * 1) Turn on the main switches, crankcase heater, and coolant heater.
 * 2) Turn on the circulating cooling water. When coolant temperature approaches 180°F, turn the heater to low.
 * 3) Fill one of the carburetor bowls with regular gasoline.
 * 4) Start the electric motor, then turn on the ignition switch.
 * 5) Turn selector dial to the bowl containing regular gasoline.
 * 6) After the engine has run for a while, check the manifold temperature. Turn on the heater if it is well below 300°F.
 * 7) Check the specific humidity while engine is warming up.

Bouncing Pin Adjustment

 * 1) Check and record barometric pressure.
 * 2) Adjust the compression ratio of the engine to the corresponding micrometer setting (Manual page 96)
 * 3) Switch from regular gasoline to a reference fuel with a known octane rating.
 * 4) Adjust the bouncing pin to read 55+3 on the knockmeter.
 * 5) Adjust the elevation of the reference fuel bowl until a maximum knock is reached. This varies the AFR.
 * 6) Now, just read the bouncing pin to the 55+3 reading.

Note: From this point forward, do not touch the bouncing pin

Testing the Unknown Fuel

 * 1) Drain the reference fuel.
 * 2) Set up the four bowls in such an order that they can be easily remembered.
 * 3) Turn selector to the bowl containing the unknown fuel.
 * 4) Adjust the compression ratio so that the knockmeter reads 55+3.
 * 5) From this point forward do not change the compression ratio.
 * 6) Using pipettes and graduates, mix a reference fuel of iso-octane and normal heptane. 200 mL should be enough to run the engine and obtain a good reading.
 * 7) Use of conversion tables makes it possible to obtain known blends using the reference fuel with either the iso-octane or normal heptane.
 * 8) Turn the selector to the newly mixed reference fuel blend.
 * 9) Adjust the bowl containing the newly mixed blend to give maximum knock.
 * 10) Repeat this procedure until two reference blends not differing more than two octane numbers bracket the fuel.
 * 11) Interpolate between the two octane numbers to obtain the octane rating of the unknown fuel.

Note: If you want to test more than one unknown fuel, repeat only the 'Testing the Unknown Fuel' section.