Stanadyne, at the 2023 Detroit Auto Show, announced they’ve developed a direct injection fuel pump and injector system for a liquid propane gas (LPG) engine project, an undertaking with their partners Propane Education & Research Council (PERC) and Katech. According to Stanadyne, using liquid propane gas has implications for cleaner propulsion, especially for the medium- and heavy-duty vehicle market. Among other benefits, it offers an approximate five to 10 percent reduction in carbon dioxide emissions and has almost no nitrogen oxide emissions compared to traditional diesel fuel.
“Internal combustion engines are the workhorses of our economy, and this advancement in technology will help them run much more sustainably using renewable fuels,” said David Zimmerman, President of Stanadyne. “The opportunity to partner with PERC and Katech on this initiative aligns with our commitment to developing solutions bridging the significant adoption gap between fossil-fueled propulsion and low-carbon and zero-carbon fueled vehicles.”
Vapor Lock Challenge
According to Stanadyne, this new offering is the industry’s first medium-duty engine system capable of delivering propane fuel at a constant 350-bar pressure directly into the engine while mitigating the potential for vapor lock. Vapor lock is a common technical challenge affecting direct injection for liquified gasses, including liquid propane gas.
Stanadyne engineers overcame the vapor lock challenge with a modified pump design that included a unique liquid flow path through the pump. They also modified the fuel injectors with additional coatings for greater wear resistance. Once paired with Katech’s vapor-lock inhibiting system, the newly modified Stanadyne components allowed vapor to return to the fuel tank while continuously delivering liquid fuel to the pump for lubrication and cooling.
“The engineering hurdles we faced with this project were numerous, particularly the challenge of vapor lock,” said Srinu Gunturu, Stanadyne Manufacturing Engineering Senior Manager. “Ultimately, we were able to overcome them and, in the process, improve both engine performance and efficiency.”
6.6-Liter GDI Engine Test
To demonstrate that Class 3 to 5 gasoline and diesel trucks can be effectively powered by liquid propane gas, the Stanadyne-Katech development team gave their new system a 250-hour performance and durability test, during which it fueled a standard 6.6L GDI engine. Ultimately, the partners aim to facilitate cleaner propulsion and make it possible for operators to keep their ICE commercial vehicles working for them while meeting sustainability goals.
“The direct liquid injection system for high-vapor pressure gases such as LPG has been technically elusive until this joint partnership between PERC, Katech, and Stanadyne materialized,” said Dr. Gokul Vishwanathan, PERC Director, Research and Sustainability. “This technology will be a significant enabler for high efficiency and low emission propane and renewable propane powered engines and hybrids for the on-road and off-road markets.”
“We are excited to help tap the incredible potential of cleaner alternative fuels,” Gunturu added.
