Description And Operation
The engine is a member of the Global Small Engine (GSE) engine family. These engines are characterized by a 77 mm bore and a stroke of 86 mm.
The GSE engines have an aluminum block that limits the overall weight. The mechanical components have been developed to reduce friction (roller rocker arms, small diameter bearings).
The GSE engines use Multiair technology and a water-cooled intercooler (WCAC).
Multiair technology manages the torque and power delivery of the engine by varying the lift profile of the intake valves without direct use of the throttle body. The main features of the Multiair engine are:
- Single camshaft
- Hydraulic exhaust tappets
- Intake tappets integrated in the Multiair actuator
- Brake servo vacuum pump
Compared to a traditional engine, the special characteristics of the Multiair system offer better combustion control and a faster response to torque requests, both of which are available and exploitable independently for each cylinder. This means:
- Reduced fuel consumption
- Reduced CO2 emissions
- Increased power and torque
- Increased driver responsiveness
- Less pollution
- Easier start-up
The Multiair system consists of a hydraulic-mechanical actuator fitted inside the Multiair engine. Multiair also includes hardware and software electronic components, built into the Powertrain Control Module (PCM) to manage the engine intake valve motion. At each engine cycle, the Multiair system controls the quantity of fresh air entering each cylinder by managing intake valve motion.