With the collaboration of the Propane Education and Research Council (PERC), Cummins has developed an Autogas demonstration engine that for the first time offers performance matching or exceeding diesel in several key areas such as torque and power output. Based on the company’s B6.7 diesel, the new 6.7 LPG direct injection engine could be well suited for a range of medium-duty applications, offering a 20-40% cost savings over 10 years compared to a diesel with similar displacement and torque curve.

The development programme was officially launched in 2016. “The goal was to develop an advanced concept that leverages the performance of the fuel,” said Sam Geckler, product line architect with Cummins. “After hundreds of hours of design, and thousands more in simulations, an LPG engine offering ‘diesel engine-like performance’ was developed.”

Some of the features include a high compression ratio, an aluminium cylinder heard, and a purpose-built fuel system. The first engine was installed in a Peterbilt 337 truck, delivered to AmeriGas for real world testing. The vehicle has already covered more than 8,000 miles.

The project is currently at the “demonstration level,” said Geckler. “That does not mean concept level, where you only build one. We built multiple engines and we are now ready to go off and show what this engine can do in a vehicle in the field.”

Saradhi Rengarajan, technical project leader with Cummins, said the most exciting aspect of the project was the torque the designers were able to achieve. Peak torque is 900 lb.-ft., far exceeding Autogas engines already in the market.

The efficiency of the engine has also led to favourable emissions performance, with CO2 emissions 11% less than a diesel, Rengarajan added. He said the 6.7L LPG offers a 28% improvement in CO2 output compared to LPG engines in the market today.

“Cummins would require further inputs on the market needs and the business case to commit to a product development and commercialisation programme,” the company said regarding the future availability of the 6.7 LPG engine. For more information, please visit this link.

10 June 2020