The Delta was a 12-cylinder inverted-V aircraft engine built by Isotta Fraschini prior to and during World War II.

[1] The Delta is a fairly rare example of a large air-cooled inline engine, which normally have cooling problems with the rearmost cylinders.

The Delta was not widely used, although it could be found on a number of production aircraft and some advanced prototypes.

The engine included a number of otherwise advanced features.

Exhaust ports were arranged to exit toward the middle of the engine, one cylinder bank being the mirror of the other, allowing the piping to be ganged below the engine nacelle.