Summary
The cubic inch (symbol in3) is a unit of volume in the Imperial units and United States customary units systems. It is the volume of a cube with each of its three dimensions (length, width, and height) being one inch long which is equivalent to 1/231 of a US gallon.[1]
| Cubic inch | |
|---|---|
 An engine with a swept piston displacement of 502 cubic inches | |
| General information | |
| Unit system | Nonstandard |
| Unit of | volume |
| Symbol | in3, cu in |
| Conversions | |
| 1 in3 in ... | ... is equal to ... |
| SI derived units | 16.387064 mL |
| US customary | 1/231 US gallon |
| nonstandard | 1/1728 ft3 |
The cubic inch and the cubic foot are used as units of volume in the United States, although the common SI units of volume, the liter, milliliter, and cubic meter, are also used, especially in manufacturing and high technology. One cubic inch is exactly 16.387064 mL.
One cubic foot is equal to exactly 1,728 cubic inches (28.316846592 L), as 123 = 1728.
Notation conventions
edit- The following abbreviations have been used to denote the cubic inch: cubic in, cu inch, cu in, cui, cu. in.
- The IEEE standard symbol is: in3[1]
- In internal combustion engines, the following abbreviations are used to denote cubic inch displacement: c.i.d., cid, CID, c.i., ci
Equivalence with other units of volume
editOne cubic inch is equal to:
- Exactly 1/1728 cubic feet
- Exactly 1/231 US gallon
- Exactly 4/231 US liquid quart
- Exactly 8/231 US liquid pint
- Exactly 32/231 US gill
- Exactly 128/231 US fluid ounce
- Exactly 1+25/231 US tablespoons
- Exactly 3+25/77 US teaspoons
- Exactly 4+100/231 US fluid drams
- Exactly 50/107521 US bushel
- Exactly 1600/107521 US dry quart
- Exactly 3200/107521 US dry pint
- ≈0.00360465 imperial gallons
- ≈0.0144186 imperial quarts
- ≈0.0288372 imperial pints
- ≈0.1153488 imperial gills
- ≈0.576744 imperial fluid ounces
- ≈1.153488 imperial tablespoons
- ≈4.613952 imperial fluid drams
- ≈0.00045058 imperial bushels
- Exactly 1/9702 barrel of crude oil
- Exactly 16.387064 milliliters
Uses of the cubic inch
editElectrical box volume
editThe cubic inch was established decades ago in the National Electrical Code as the conventional unit in North America for measuring the volume of electrical boxes. Because of the extensive export of electrical equipment to other countries, some usage of the non-SI unit can be found outside North America.
Engine displacement
editNorth America
editThe cubic inch was formerly used by the automotive industry and aircraft industry in North America (through the early 1980s) to express the nominal engine displacement for the engines of new automobiles, trucks, aircraft, etc. The cubic inch is still used for this purpose in classic car collecting. The auto industry now uses liters for this purpose, while reciprocating engines used in commercial aircraft often have model numbers based on the cubic inch displacement. The fifth generation Ford Mustang has a Boss 302 version that reflects this heritage - with a five-liter (302 cubic inch) engine similar to the original Boss. Chevrolet has also revived this usage on its 427 Corvette. Dodge has a "Challenger 392" (a conversion from its 6.4 liter V8 engine).
See also
editReferences
edit- ^ a b IEEE Standard Letter Symbols for Units of Measurement (SI Customary Inch-Pound Units, and Certain Other Units) (Technical report). IEEE. 2004. 260.1-2004.