This paper describes the development of a dedicated liquefied petroleum gas (LPG) fueled spark-ignition engine and vehicle (Chrysler minivan) for the 1996 Propane Vehicle Challenge. This student competition was intended to advance the development of propane-fueled vehicles, to encourage innovation in propane vehicle technology, and to provide student engineers with a hands-on learning experience.
The student designs included LPG fuel storage and delivery systems, engine modifications (such as increased compression ratio by the use of domed pistons), a vapor fuel injection system, custom electronic controls, and specialized catalyst units. The vapor fuel injection system design included a vaporizer (for cold ambient temperatures) and port injection designed to inject LPG vapor at 276 kPa (40 psia).
The LPG-fueled engine possessed performance and efficiency parameters as good as, or better than, the original gasoline-fueled engine. In general, the exhaust emissions were lower for the LPG vehicle than for the original gasoline vehicle. At the conclusion of the competition, the Texas A&M University entry was awarded first place overall, and the award for the lowest emissions.