A testing device allows a test engine (such as a single-cylinder test engine) to experience the air exchange characteristics of a multi-cylinder test engine having a greater number of cylinders. The test engine receives air from an air source (such as the atmosphere) through the interior passage of an air intake adapter, wherein valves on the passage walls separate the interior passage from a negative or positive pressure source. A processor (such as a computer) may actuate the valves to allow air to be pulled from the passage to simulate the effect of air intake into additional virtual cylinders (i.e., cylinders that would operate in tandem with the cylinder(s) of the test engine if the test engine had a greater number of cylinders), and/or to simulate the effect of forced air induction (i.e., turbocharging or supercharging).