PP 01

What five events take place in a two-stroke-cycle engine?. Intake, compression, exhaust, scavenging, cooling. Compression, ignition, power, lubrication, cooling. Intake, compression, ignition, power, exhaust. Intake, scavenging, ignition, pressure, exhaust.

How many degrees of crankshaft rotation are required to include all the strokes in an Otto-cycle engine?. 360° or 1 revolution. 540° or 1.5 revolutions. 720° or 2 revolutions. 1440° or 4 revolutions.

At the end of what stroke does valve overlap occur?. At the end of the intake stroke. At the end of the exhaust stroke. At the end of the compression stroke. At the end of the power stroke.

What is the formula for work?. Work = Pressure × Time. Work = Mass × Velocity. Work = Force × Area. Work = Force × Distance.

What is the formula for power?. Power = Work ÷ Time. Power = Work × Time. Power = Force ÷ Distance. Power = Force × Distance.

horsepower equals how many foot-pounds per minute?. 330. 3300. 33,000. 330,000.

horsepower equals how many foot-pounds per second?. 33. 330. 550. 1500.

How much horsepower is required to lift 4000 pounds 33 feet in one minute?. 2 HP. 3 HP. 4 HP. 6 HP.

How many foot-pounds of work per second is an engine capable of if it delivers 145 shaft horsepower?. 29,750. 55,000. 79,750. 145,000.

What is meant by thermal efficiency of an engine?. Ratio of cylinder pressure to temperature. Ratio of useful work to fuel supplied. Ratio of heat energy converted to work versus heat energy in fuel. Ratio of indicated HP to brake HP.

What is meant by mechanical efficiency of an engine?. Ratio of brake horsepower to indicated horsepower. Ratio of stroke to piston area. Ratio of RPM to torque. Ratio of fuel energy to exhaust losses.

What is meant by volumetric efficiency of an engine?. Ratio of fuel mass to engine displacement. Ratio of air mass to piston speed. Ratio of amount of air taken in to total piston displacement. Ratio of temperature to pressure at intake.

What is meant by compression ratio?. Volume at BDC ÷ volume at TDC. Volume at TDC ÷ volume at BDC. Pressure at idle ÷ pressure at full power. Cylinder displacement ÷ stroke length.

What limits the compression ratio an engine can have?. Engine RPM. Oil viscosity. Detonation risk / critical air-fuel pressure. Exhaust valve temperature.

What is the total displacement of a 9-cylinder engine with a 5.5-inch bore and 6-inch stroke?. 823 cubic inches. 1110 cubic inches. 1283 cubic inches. 1440 cubic inches.

What is the total displacement of a 6-cylinder opposed engine with a 4.5-inch bore and 5-inch stroke?. 22 cubic inches. 477 cubic inches. 512 cubic inches. 623 cubic inches.

What is the indicated horsepower of a six-cylinder engine with a 4-inch bore, 4-inch stroke, IMEP of 120 PSI, turning 2600 RPM?. 83 HP. 105 HP. 119 HP. 154 HP.

What is the indicated horsepower of a nine-cylinder engine with a 6-inch stroke, 5.5-inch bore, IMEP of 130 PSI, turning 2250 RPM?. 245 HP. 374 HP. 474 HP. 590 HP.

What is meant by brake horsepower?. HP measured at the propeller tips. Horsepower delivered to the output shaft. Horsepower before mechanical losses. Horsepower used for accessories only.

What is meant by friction horsepower?. HP required to start the engine. HP wasted in the exhaust system. Indicated HP – Brake HP. HP absorbed by the propeller.

The firing order of an 18-cylinder radial engine is?. 1-3-5-7-9-11-13-15-17-2-4-6-8-10-12-14-16-18. Add 11 and subtract 7, repeating sequence. 1-5-9-13-17-3-7-11-15-2-6-10-14-18-4-8-12-16. Sequential: 1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18.

If the volume of a cylinder is 12 inches at TDC and 90 inches at BDC, what is its compression ratio?. 5:1. 6.5:1. 7.5:1. 8:1.

If a 7-cylinder engine has a 3-lobe cam ring, what is its cam ring speed relative to the crankshaft?. 1/2 crankshaft speed. 1/3 crankshaft speed. 1/6 crankshaft speed. Same speed as crankshaft.

If a 9-cylinder radial engine has a 5-lobe cam ring, what is its cam ring speed relative to the crankshaft?. 1/2. 1/5. 1/9. 1/10.

In the above question, what direction does the cam ring turn in relation to the crankshaft?. Opposite direction. Same direction. Counterclockwise only. Clockwise only.

What is the flat area on a cam ring that provides no lift called?. The dead zone. The cam track. The dwell area. The heel.

What is meant by valve overlap?. Ignition beginning before compression. Both valves closed simultaneously. Period when both intake and exhaust valves are open. Period when neither valve is open.

Why is valve lead and lag greater at bottom dead center than at top dead center?. Piston travel per degree of crank rotation is greater at the bottom. Port pressure changes at BDC. Valve spring harmonics are strongest at BDC. Cam followers require oil splash.

How many throws are there on a two-row radial engine?. One. Two. Four. Nine.

What are deep groove ball bearings used for on a radial engine?. Thrust load only. Radial load only. Radial and axial loads. Crankshaft end-play only.

What are cylinder heads normally made of?. Cast iron. Carbon steel. Cast aluminum. Heat-treated bronze.

Why are nitrided cylinder barrels used?. Reduce oil temperature. Increase piston speed. Surface hardness reduces wear on cylinder wall. Provide anti-detonation resistance.

What type of piston rings are used with a chrome-plated cylinder?. Chrome rings. Cast iron rings. Grey steel rings. Stainless rings.

How are articulating rods connected to the master rod?. Roller pins. Swaged rivets. Knuckle pins. Bronze bushings.

Of what material are valve guides usually made?. Stainless steel. Bronze or similar alloy. Cast aluminum. Chrome moly steel.

Why are some exhaust valves filled with metallic sodium?. Stabilize valve seating. Reduce detonation. Transfer heat away from the valve head. Improve lubrication.

How are valve seats installed in the head of an aircraft engine?. Left-hand threaded. Press fit cold only. Heated head, chilled seat, interference fit. Installed with retaining clips.

What is done to valve tips and stems to increase wear resistance?. Polished smooth. Nitrided. Hardfaced or stellited. Chrome washed.