0 5 10 15 20 25 30 35 40 Nozzle pressure or lb/hr fuel  fl ow (gauge) Fuel nozzle (one per cylinder) Flow divider Nozzle discharge pressure Metered fuel pressure Ambient air pressure Figure 2-36.  Flow divider.  Figure 2-37.  Flow divider cutaway. simple pressure gauge can be calibrated in fuel flow in gallons  per hour and be employed as a flowmeter. Engines modified  with turbosuperchargers must use shrouded nozzles. By the  use of an air manifold, these nozzles are vented to the injector  air inlet pressure. The Continental fuel-injection system injects fuel into the  intake valve port in each cylinder head.  [Figure 2-39]  The  system consists of a fuel injector pump, a control unit, a fuel  manifold, and a fuel discharge nozzle. It is a continuous-flow  type, which controls fuel flow to match engine airflow. The  continuous-flow system permits the use of a rotary vane pump  which does not require timing to the engine. The fuel pump is a positive-displacement, rotary-vane type with  a splined shaft for connection to the accessory drive system of  the engine.  [Figure 2-40]  A spring-loaded, diaphragm-type  relief valve is provided. The relief valve diaphragm chamber  is vented to atmospheric pressure. A sectional view of a fuel- injection pump is shown in  Figure 2-41 . Continental/TCM Fuel-Injection System Fuel-Injection Pump Figure 2-38.  Fuel nozzle assembly. 2-25