The Continental A40 engine is a carbureted four-cylinder, horizontally opposed, air-cooled aircraft engine that was developed especially for use in light aircraft by Continental Motors.

At the time there were a number of small engines available but all suffered from either high cost, complexity, or low reliability.

The A-40 addressed all those shortcomings and was instrumental in the production of light aircraft in the difficult economic constraints of the period.

All engines in this family have a 5.2:1 compression ratio and were designed to run on fuel with a minimum octane rating of 73.

[2][3] The entire family of engines had its certification terminated on 1 November 1941.