It is commonly called a rotary engine, though this name applies also to other completely different designs.
Sometimes it is called an inline-eight engine.
An engine similarly mounted along the frame of a motorcycle is called an in-line engine.
If the vehicle pumps water it is called an engine.
Such a design is called a semi-uniflow engine.
This feature led PubSub to call itself a matching engine.
The antimatter rocket could be a kind called a beam-core engine, he speculated.
Arbok, I've noticed you refuse to call it an engine.
A third class of rules engine might be called a deterministic engine.
The basic engine is called a four-stroke engine because each piston must move up and down twice to complete a cycle.