Login or register (free and only takes a few minutes) to participate in this question.
You will also have access to many other tools and opportunities designed for those who have language-related jobs (or are passionate about them). Participation is free and the site has a strict confidentiality policy.
Explanation: Runners are the air passages in a manifold that take the air flow into the cylinders/combustion chambers in internal combustion engines. The camshafts control the opening/closing of the engine's intake/exhaust valves and the IMRC controls the operation of the set of runners for low or high rpm ranges to provide optimum engine performance. I hope it helps.
References: personal glossaries + experience with automotive industries