Engine Displacement Calculator

What Engine Displacement is for

Engine Displacement Calculator is the page to open when you need engine displacement from measurements you already have. It belongs with the other automotive calculators because that is the work this arithmetic supports. Power at the crank for that engine is the horsepower. Type the entries first. The result stays hidden until you press Calculate, so a half-finished form never flashes a number you might mistake for the answer.

How to fill in this calculator

1. Bore Size. Enter the value this part of the job needs. The unit list on this field includes in, mm, cm.
2. Stroke Length. Enter the value this part of the job needs. The unit list on this field includes in, mm, cm.
3. Cylinder Count. Enter the value this part of the job needs.

The formula in plain language

Displacement is the volume the pistons sweep. Multiply π/4 by the bore squared, then by the stroke, then by the number of cylinders. Bore and stroke must be in the same unit. The result in cubic inches times 16.387 is cubic centimeters.

A worked example

A 4.00 inch bore, a 3.48 inch stroke, and 8 cylinders is 349.8 cubic inches, about 5.73 liters.

Displacement, compression, airflow, and the torque curve describe one engine. This engine displacement result should be read with carburetor CFM and torque at that rpm.

Mistakes that move the answer

• Measure bore and stroke in the same unit before you square the bore.
• A deck plate or a stroker crank changes the number even when the block casting stays the same.

How to check the result

After Calculate shows the engine displacement result, redo the last operation with a pencil using the rounded figures on the screen. Matching that check means the inputs were read correctly. If you edit a label or a sentence in this HTML file, reload the page. The form and this article both live in the file, so the edit is what visitors will read.