RECIPROCATING ENGINE PART 2

How may it be determined that a reciprocating engine with a dry sump is pre-oiled sufficiently?. The engine oil pressure gauge will indicate normal oil pressure. Oil will flow from the engine return line or indicator port. When the quantity of oil specified by the manufacturer has been pumped into the engine.

Full-floating piston pins are those which allow motion between the pin and. the piston. both the piston and the large end of the connecting rod. both the piston and the small end of the connecting rod.

The horsepower developed in the cylinders of a reciprocating engine is known as the. shaft horsepower. indicated horsepower. brake horsepower.

During overhaul, reciprocating engine exhaust valves are checked for stretch. with a suitable inside spring caliper. with a contour or radius gauge. by placing the valve on a surface plate and measuring its length with a vernier height gauge.

What does valve overlap promote?. Lower intake manifold pressure and temperatures. A backflow of gases across the cylinder. Better scavenging and cooling characteristics.

Compression ratio is the ratio between the. piston travel on the compression stroke and on the intake stroke. combustion chamber pressure on the combustion stroke and on the exhaust stroke. cylinder volume with piston at bottom dead center and at top dead center.

Cam-ground pistons are installed in some aircraft engines to. provide a better fit at operating temperatures. act as a compensating feature so that a compensated magneto is not required. equalize the wear on all pistons.

The valve clearance of an engine using hydraulic lifters, when the lifters are completely flat, or empty, should not exceed. 0.00 inch. a specified amount above zero. a specified amount below zero.

The volume of a cylinder equals 70 cubic inches when the piston is at bottom center. When the piston is at the top of the cylinder, the volume equals 10 cubic inches. What is the compression ratio?. 10:7. 10:1. 7:1.

What could cause excessive pressure buildup in the crankcase of a reciprocating engine?. Plugged crankcase breather. Improper warmup operation. An excessive quantity of oil.

One of the best indicators of reciprocating engine combustion chamber problems is. excessive engine vibration. starting difficulties. spark plug condition.

The primary purpose in setting proper valve timing and overlap is to. permit the best possible charge of fuel/air mixture into the cylinders. gain more thorough exhaust gas scavenging. obtain the best volumetric efficiency and lower cylinder operating temperatures.

Reduced air density at high altitude has a decided effect on carburetion, resulting in a reduction of engine power by. excessively enriching the fuel/air mixture. excessively leaning the fuel/air mixture. reducing fuel vaporization.

Backfiring through the carburetor generally results from the use of. an excessively lean mixture. excessively atomized fuel. an excessively rich mixture.

Which statement is correct regarding engine crankshafts?. Moveable counterweights serve to reduce the dynamic vibrations in an aircraft reciprocating engine. Moveable counterweights serve to reduce the torsional vibrations in an aircraft reciprocating engine. Moveable counterweights are designed to resonate at the natural frequency of the crankshaft.

Before attempting to start a radial engine that has been shut down for more than 30 minutes,. turn the propeller by hand three or four revolutions in the opposite direction of normal rotation to check for liquid lock. turn the ignition switch on before energizing the starter. turn the propeller by hand three to four revolutions in the normal direction of rotation to check for liquid lock.

A condition that can occur in radial engines but is unlikely to occur in horizontally opposed engines is. oil-fouled spark plug. valve overlap. hydraulic lock.

Which of the following would most likely cause a reciprocating engine to backfire through the induction system at low RPM operation?. Idle mixture too rich. Clogged derichment valve. Lean mixture.

On which strokes are both valves on a four-stroke cycle reciprocating aircraft engine open?. Power and exhaust. Intake and compression. Exhaust and intake.

If the crankshaft runout readings on the dial indicator are plus .002 inch and minus .003 inch, the runout is. .005 inch. plus .001 inch. minus .001 inch.

By use of a differential pressure compression tester, it is determined that cylinder 3 of a nine-cylinder radial engine will not hold pressure after the crankshaft has been rotated 260° from top dead center compression stroke cylinder 1. How can this indication usually be interpreted?. A normal indication. Exhaust valve blow-by. A damaged exhaust valve or insufficient exhaust valve clearance.

Which of the following would indicate a general weak-engine condition when operated with a fixed-pitch propeller or test club?. Lower than normal static RPM, full throttle operation. Manifold pressure lower at idle RPM than at static RPM. Lower than normal manifold pressure for any given RPM.

What is the purpose of the safety circlet installed on some valve stems?. To hold the valve guide in position. To hold the valve spring retaining washer in position. To prevent valves from falling into the combustion chamber.

Which statement pertaining to air-fuel ratios is true?. The mixture ratio which gives the best power is richer than the mixture ratio which gives maximum economy. A rich mixture is faster burning than a normal mixture. The mixture ratio which gives maximum economy may also be designated as best power mixture.

What is the principal advantage of using propeller reduction gears?. To enable the propeller RPM to be increased without an accompanying increase in engine RPM. To enable the engine RPM to be increased with an accompanying increase in power and allow the propeller to remain at a lower, more efficient RPM. To enable the engine RPM to be increased with an accompanying increase in propeller RPM.

As the pressure is applied during a reciprocating engine compression check using a differential pressure tester, what would a movement of the propeller in the direction of engine rotation indicate?. The piston was on compression stroke. The piston was on exhaust stroke. The piston was positioned past top dead center.

A nine-cylinder engine with a bore of 5.5 inches and a stroke of 6 inches will have a total piston displacement of. 740 cubic inches. 1,425 cubic inches. 1,283 cubic inches.

One cause of afterfiring in an aircraft engine is. sticking intake valves. an excessively lean mixture. an excessively rich mixture.

Which of the following statements is true?. Preignition is caused by improper ignition timing. Detonation occurs when an area of the combustion chamber becomes incandescent and ignites the air-fuel mixture in advance of normal timed ignition. Preignition is caused by incandescent objects in the cylinder.

Which of these conditions will cause an engine to have an increased tendency to detonate?. Late ignition timing. High manifold pressure or high intake air temperature. Late ignition timing and an overheated engine.

If air is heard coming from the crankcase breather or oil filler during a differential compression check, what is this an indication of?. Exhaust valve leakage. Intake valve leakage. Piston ring leakage.

When will small induction system air leaks have the most noticeable effect on engine operation?. At high RPM. At maximum continuous and takeoff power settings. At low RPM.

Which of the following will be caused by excessive valve clearance of a cylinder on a reciprocating aircraft engine?. Reduced valve overlap period. Intake and exhaust valves will open early and close late. A power increase by shortening the exhaust event.

During overhaul of an engine, a first step of inspection on a crankshaft should be to. perform a magnaflux inspection for cracks. perform a runout check. inspect the bearing surfaces for pitting.

An engine misses in both the right and left positions of the magneto switch. The quickest method for locating the trouble is to. check for one or more cold cylinders. perform a compression check. check each spark plug.

If the exhaust valve of a four-stroke cycle engine is closed and the intake valve is just closed, the piston is on the. intake stroke. power stroke. compression stroke.