Last week, Cummins and Canadian company Westport Innovations announced a joint venture to manufacture and market new-technology natural-gas engines based on Cummins diesels. In a webcast press conference Friday, company officials offered more details on the engines.

The product line will include existing spark-ignition Cummins B- and C-Series, plus a new-technology high-pressure-gas fuel injected engine based on the 15-liter ISX.
The new joint venture says that for the first time, thanks to high-pressure direct injection (HPDI), truck operators have the availability of diesel-type performance up to 600 horsepower from a natural gas fueled engine.
The technology, developed by Vancouver, B,C.-based natural gas fuel systems Westport Innovations, uses a small quantity of diesel fuel injected into the combustion chamber to initiate combustion. The gaseous fuel is then injected and the engine generates its power from the natural gas fuel. The truck thus has to carry two different fuels, with the diesel tank capacity probably being around 5% to 10% of the natural gas, said Tom Kieffer, executive director of marketing for Cummins.
With the efficiency of the HPDI, the engines develop similar horsepower from natural gas as they can from diesel. However, different energy densities in the fuel mean that for equivalent range, a truck will need to carry 1.7 times as much liquid natural gas as diesel fuel.
According to Alex Klopfer, vice president of marketing, for Westport, over the life of the truck, the price differential for the fuels, plus more favorable tax and savings in maintenance, will mean the additional cost to outfit a truck chassis for liquid natural gas fuel will be more than offset. Today, those costs typically run $30,000 to $40,000, but Klopfer said the predicted market acceptance of HPDI natural gas-fueled trucks would see prices falling through increased volumes.
Cummins' Kieffer said that the ISX engine is already certified at the 2004 standard for2.5 g Nox/NMHC, showing it is a clean-burning engine.
Cummins will build the natural gas engines at its existing sites as appropriate to the model.
The joint venture company will market the ISX engine and Cummins existing B5.9G, B5.9LPG, and C89.3G spark-ignition engines. These cover ratings between 150 and 275 horsepower, and Cummins says it sold 1,800 of these engines in 2000. The ISX is still some way from production, but it is anticipated it will be available in ratings up to 600 horsepower.
At the announcement, Cummins and Westport executives said that target markets for the natural gas truck engines would be utility and municipal fleets, and with the higher horsepower and torque of the diesel-like HPDI engines, there would be major opportunities among centrally fueled heavy distribution and vocational fleets. Applications such as refuse collection were mentioned, along with distribution fleets using medium-duty trucks. Other potential customers could well include grocery fleets that need full class 8 tractors and the associated power.
Executives also addressed infrastructure and gas pricing questions, saying that the solutions would be longer term. Natural gas is a far more abundant fuel than even oil, said Klopfer, and indications are that major investments are being made in liquid natural gas distribution sites to ease fueling concerns.