Final answer:
A 9 cylinder radial engine would have 9 breaker cam lobes, as there is one lobe per cylinder designed to trigger the spark at the correct timing in the engine's cycle.
Step-by-step explanation:
The question pertains to the construction of a 9 cylinder radial engine which is used in some aircraft and other machinery. Specifically, we are looking at the breaker cam lobes of the engine's ignition system. In a radial engine, the breaker cam or distributor rotor typically has one lobe per cylinder as each cylinder requires a spark for its ignition cycle. Therefore, a 9 cylinder radial engine would have 9 breaker cam lobes. Each lobe is responsible for triggering the spark in the associated cylinder's spark plug at the correct timing in the engine's cycle. For a 9-cylinder engine, the firing order is sequenced so that every cylinder fires once in every cycle of the engine in a radial manner.