Technician A says an intake manifold that delivers both air and fuel (carburetor or TBI)is designed to cause turbulence so that the air and fuel mix while they are being delivered to the cylinders. Technician B says in an air only type manifold (PFI)the length of the runners is designed to achieve the best performance during a particular range of engine speeds. Who is correct?
A)A only
B)B only
C)both A and B
D)neither A nor B

Question

Quizplus · Accepted Answer

Both technicians are correct. Technician A is correct in stating that intake manifolds designed for carburetor or Throttle Body Injection (TBI) systems aim to mix air and fuel efficiently through turbulence. Technician B is correct in stating that for Port Fuel Injection (PFI) systems, the length of the intake runners is optimized for performance at specific engine speed ranges, utilizing the principle of resonance and air column inertia to improve cylinder filling at those speeds.

Technician a Says an Intake Manifold That Delivers Both Air