Ag Mech - Engine Operations

On four-stroke cycle engines, the camshaft rotates at ___ the speed of the crankshaft

1/2

flywheel

A heavy wheel fastened to one end of the crankshaft to improve the running quality of the engine. The inertia of the flywheel keeps the crankshaft spinning and smoothes engine operation.

oil slinger

Lubricates engine

magneto

an electrical generator that produces power when rotated

crankcase cover

A part of the engine that holds parts together in the crankcase and keeps foreign matter out. This also serves as a way to service the engine.

valve spring

A spring attached to a valve to return it to the seat after it has been released from the lifting or opening operation.

All engine blocks are produced as one-piece units.

False - can also be two piece units

Aluminum is a ferrous metal.

False - nonferrous

A radial load is a load applied parallel to the shaft.

False - perpendicular

Head gaskets are made from hard metals and graphite layered together.

False - soft metals

___ is the property of matter by which any physical body persists in its state of rest or uniform motion until acted upon by an external force.

Inertia

cylinder head

Metal section bolted on top of the engine block and forms part of the combustion chamber.

connecting rod

The connecting link between the piston and the crankshaft

piston

a part of an engine that consists of a short cylinder that fits inside a tube and moves up and down or backwards and forwards to make other parts of the engine move

Camshaft

a rotating shaft within the engine that opens and closes the intake and exhaust valve in the engine

spark plug

electrical device that fits into the cylinder head of an internal-combustion engine and ignites the gas by means of an electric spark

The ___ is the main structure of an engine which supports and helps maintain alignment of internal and external components.

engine block

The value ___ is the machine surface of a valve that mates with the valve seat to seal the combustion chamber.

face

engine block

forms the framework for the engine cylinders and reciprocating assembly

A ___ is the filler material placed between the cylinder block and cylinder head to seal the combustion chamber.

head gasket

oil ring

is a piston ring designed to secure proper distribution of lubricating oil over the length of cylinder wall traversed by the piston.

An ___ engine is an engine that has valves and related components located in the cylinder head.

over head valve (OHV)

Valve ___ is the period during engine operation when both intake and exhaust valves are open at the same time.

overlap

A ___ is a cylindrical engine component that slides back and forth in the cylinder bore by forces produced during the combustion process.

piston

The ___ event is an engine operation event in which hot expanding gases force the piston head away from the cylinder head.

power

The ___ dynamometer is a dynamometer used to measure engine torque using a brake that exerts pressure on a spring scale.

prony brake

A ___ is the removeable section of a two-piece connecting rod that provides a bearing surface for the crankpin journal.

rod cap

compression ring

seals the clearance gap between the piston and cylinder walls

The ___ of a piston is the portion of the piston closest to the crankshaft that helps align the piston as it moves in the cylinder bore.

skirt

The ___ of an engine is the linear distance that a piston travels in the cylinder bore from top dead center to bottom dead center.

stroke

The ___ is a removeable part of the engine crankcase that serves as an oil that serves as an oil reservoir and provides access to internal parts.

sump

tappet

the engine component for transferring motion to cause valves to open and close

The ___ is the measurement from the center of the crankshaft to the center of the crankpin journal, which is used to determine the stroke of an engine.

throw

valve stem

a long, slender metal shaft attached to the handwheel and flow-control element of a valve.

Carburetor

(n) a device in an internal combustion engine for mixing air with fine spray or liquid fuel

gas tank

holds fuel

The atmospheric pressure at sea level is ___ psi.

14.7

The ___ is the point at which the piston is farthest from the cylinder head.

Bottom dead center

The compression ratio of an engine is a comparison of the volume of the combustion chamber with the piston at ___ to the volume of the combustion chamber with the piston at ___.

Bottom dead center (BDC), Top dead center (TDC)

___ horsepower, or shaft horsepower, is the amount of usable power taken from an engine.

Brake

___ efficiency is a measurement that compares the amount of chemical energy available in fuel converted into heat energy used to produce useful work.

Thermal

A rod bearing provides a low-friction pivot point between the connecting rod and the crankshaft and the connecting rod and piston.

True

Cast iron cylinder blocks are heavier and more expensive, but are more resistant to wear and less prone to heat distortion than cast aluminum alloy cylinder blocks.

True

Internal combustion engines convert potential chemical energy in the form of heat derived from a fuel into mechanical energy.

True

Piston rings are commonly made from cast iron.

True

crankshaft

Turns the piston's up and down motion into circular motion

A ___ journal is a precision ground surface within which the crankshaft rotates.

bearing

The ___ of an engine is the diameter of the cylinder bore.

bore

The ___ is the volume of compressed air-fuel mixture trapped inside the combustion chamber ready for ignition.

charge

A ___ is an engine component that transfers motion from the piston to the crankshaft and functions as a lever arm.

connecting rod

A ___ is an engine component that houses and supports the crankshaft.

crankcase

The ___ is a gear located on the crankshaft that is used to drive other parts of an engine.

crankgear