Question

in which step of the four - stroke engine cycle does the heat from the combustion reaction cause the pistons to move? a. compression and ignition b. air and fuel intake c. exhaust d. combustion and expansion

Explanation:

In a four - stroke engine cycle, during the combustion and expansion stroke, the fuel - air mixture ignites. The heat from the combustion reaction causes the gases to expand rapidly, which in turn pushes the pistons down.

Answer:

D. Combustion and expansion