Engine Performance
This is the rate at which an engine can perform work, calculated from its torque and RPM
Horsepower
This measurement refers to the total volume displaced by all of an engine's pistons.
Engine Displacement
This is the ideal ratio of air to fuel for complete combustion in an engine, often around 14.7:1 for gasoline.
Stoichiometric Air-Fuel Ratio
This tool is used to measure the engine's power output and torque under a controlled load.
Dynamometer
The rotational speed of an engine is measured in these units.
RPMs (Revolutions Per Minute)
This is the rotational or twisting force that an engine produces.
What is Torque?
This term refers to the diameter of an engine's cylinder.
Bore
This measurement indicates how effectively an engine fills its cylinders with air or the air-fuel mixture during each intake stroke.
This tool can measure an engine's rotations per minute.
Tachometer
Engine displacement is often measured in cubic inches (CID) or these metric units.
Liters or Cubic Centimeters
This term describes an engine's efficiency by measuring how much fuel is consumed to produce a certain amount of power.
Brake Specific Fuel Consumption (Hard One Sorry)
This is the distance the piston travels up and down within the cylinder.
Stroke
A vacuum gauge on the intake manifold can help diagnose the health of an engine by measuring this.
Intake Manifold Vacuum
Used to diagnose engine health, this tool measures the pressure created in the cylinders.
Compression Tester
This is the SI unit for torque, named after a famous physicist.
Newton-Meter (NM)
A dynamometer is a device used to measure this key metric, which is then used to calculate an engine's horsepower.
This is the ratio of the volume inside a cylinder with the piston at the bottom of its stroke to the volume when the piston is at the top of its stroke.
Compression Ratio
A high, steady reading on a vacuum gauge at idle is a sign of a healthy engine and indicates good performance from these.
Piston Rings or Valve Seals
This sensor measures the air-fuel ratio by detecting the oxygen content in the exhaust.
Oxygen Sensor
The unit for work done by an engine, calculated as one newton of force times one meter.
Joules
The calculation of this involves measuring the force on a lever arm to determine the rotational force of the engine.
Torque
In an engine's mathematical calculations, this value for a single cylinder is found by multiplying the area of the bore by the stroke.
Cylinder Volume
This is the term for the average pressure acting on a piston during the power stroke.
Mean Effective Pressure
In an engine test bench, a scale can be used to measure this, which is a key component for calculating torque.
Force
This unit for pressure is approximately equal to 0.491 psi and is used to measure engine vacuum.
Inches of Mercury (inHg)?