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Ethanol is commonly employed as a transportation fuel in Brazil. However, since pure ethanol’s flash point is 12°C, flex-fuel vehicles marketed in Brazil are currently equipped with a redundant fuel system which delivers gasoline during cold starts below [typically] 18°C. Since these low temperatures are infrequently experienced in Brazil, gasoline in the auxiliary fuel tank may evaporate and/or varnish during extended dormant periods, resulting in poor quality or no-starts. It is therefore desirable to eliminate the gasoline system by vaporizing a sufficient quantity of ethanol to enable cold starts at low ambient temperatures. A port fuel injector capable of rapidly heating ethanol above its flash point has been developed which eliminates the need for the redundant fuel system. During cold-start conditions, the vehicle’s controller commands power to an electrical heater contained within each injector.

Brazilian ethanol vehicles are typically equipped with an auxiliary gasoline sub-tank fuel system which aids cold starting and drivability for low ambient temperatures. Port fuel injectors capable of rapidly heating ethanol have been developed to eliminate this auxiliary system. These injectors also enable reductions in emissions. Computational Fluid Dynamics (CFD) is used in conjunction with Taguchi Robust Engineering methods to optimize the heat exchanging geometry of these heated injectors. Simulation results are confirmed with experimental hardware and engine cold start testing. Modeling results, experimental hardware, and engine cold start performance is presented and discussed.

Delphi has developed a Continuously Variable Valve Lift [CVVL] mechanism to improve spark ignition engine part throttle fuel economy through the minimization of pumping losses and reduction of cam drive torque. The latest CVVL design is focused on meeting valve lift duration targets derived from combustion analysis at key speed and load points, reducing packaging envelope, and reducing part count for low cost. Delphi's CVVL design process, simulation used to predict performance, and hardware confirmation testing will be presented and discussed in this paper.

Gasoline direct injection (GDi) fuel pumps use a plunger reciprocating in a sleeve to deliver pressurized fuel. Current industry-standard clearances between the plunger and sleeve create internal fuel leakage rates which are large enough to negatively affect pumping efficiency at low engine speeds. A polymer seal located between the plunger and sleeve has been developed to minimize the fuel leak solving the low engine speed efficiency problem. This paper will present analytical, experimental and validation testing results of improved pumping efficiency attained with this new seal. With the plunger seal, pumping efficiencies are shown to improve by a few percentage points at high engine rpms (erpm) but can double at low (cranking and idle) rpms, without degradation of performance after durability testing.

LEV-3 regulation changes require 100% SULEV30 fleet average by 2025. While present applications meeting SULEV30 are predominately small displacement 4-cylinder engines, LEV-3 standards will require larger displacement engines to also meet SULEV30. One concept previously investigated to reduce the cold start engine-out HC emissions was to heat the fuel injected during the cold start and initial engine idle period. Improved atomization and increased vaporization of heated fuel decreased wall wetting and unburned fuel. This resulted in more fuel available to take part in combustion, thus reducing the required injected fuel mass and HC emissions. Single cylinder engine testing with experimental heated Gasoline Direct Injection (GDi) injectors was conducted at 40°C engine coolant and oil temperature conditions. The operating mode simulated cold start idle operating conditions, with split injection for improved Catalyst Light-Off (CATLO) times.