Cubic inch displacement (CID) is the imperial measurement of an engine's total cylinder volume. It is calculated by multiplying the cross-sectional area of a cylinder bore by the piston stroke length, and then multiplying by the number of cylinders. Engine size was historically designated by CID in the American automotive market before the industry transitioned to metric liters.
The block casting numbers confirm it's a 350 CID small block, not a 305.
To convert CID to liters, divide the cubic inches by 61.02. For example, a 302 CID engine is approximately 4.9 liters, commonly badged as a 5.0L.
Also heard as
- cubic inch displacement
- cubic inches
Related terms
Big block
A physically massive V8 engine designed for high displacement and torque.
Crate engine
A fully assembled, brand-new or remanufactured engine delivered ready to install.
Overbore
To machine an engine cylinder to a larger diameter than its factory specification.
There is no replacement for displacement
This classic hot-rodding maxim asserts that increasing an engine's internal volume is the most reliable way to make power.