Recent order from MetroLink, the Moline, Ill., transit system, or 12 of a possible 18 CNG- fueled El Dorado buses, all powered by John Deere 8.1 L engines, marks the latest step in John Deere Power Systems expanding gaseous-fueled engine program.

Ten of the 30 ft. Metrolink buses, which began transit operation in July, started life earlier this year at the Salt Lake City Olympics, "which certainly proved reliability and operation of the vehicle under demanding conditions and at altitude," said Deere's Tom Cummings, manager, natural gas engine sales.

Since its launch in 1996, Deere's natural gas engine program has expanded from its base in school buses to include commercial transit buses, refuse vehicles, Class 7 utility trucks, as well as pick-up and delivery trucks.
Deere's natural gas engine program has centered on its 8.1 L model 6081HFN engine.  A turbocharged, air-to-air charge-air cooled engine, the 6081HFN has been available with a 250 hp at 2200 rpm rating developing 800 lb.ft. of torque at 1350 rpm.

Now, Deere's Waterloo, Iowa-based Power Systems group has introduced a 275 hp at 2200 rpm rating for the 8.1 with the same torque output, as well as a 280 hp rating at 2200 rpm that develops 900 lb.ft. of torque at 1600 rpm. The new ratings are among a number of technical changes Deere has made to 608IHFN, as its natural gas program begins to come of age.

Deere's gaseous engine efforts began in 1996 with the application 8.1 L lean burn, closed loop, adaptive learn natural gas engines in Blue Bird All American school bus chassis.  In 1999, Thomas Built also began offering the 250 hp 8.1 L natural gas engine in its Saf-T-Liner bus chassis.  Both are targeted primarily at school bus use in California.

For example, an LNG capable model is due for introduction early next year, and current engines now feature new humidity and knock sensors.  "The humidity sensor package is of key elements within the natural gas market that is critical for good performance of these engines," Cummings said.

The engines are all gasified on the production line at Waterloo.
Cummings said that while the lower portion of the engine is still a diesel base, the upper half and anything to do with the combustion system is specifically designed and sourced for natural gas operation.  "All are natural gas derived components that we developed in conjunction with Southwest Research Institute," Cummings said. Glen Chrusciel, business manager, natural gas added that the natural gas engines have a lower compression ratio (10:1), a cylinder head unique to this use, special pistons and valve seat inserts, a new ECU and a Woodward injector block.  Cummings added that all three versions of the engine would be released with oxidation catalysts early in 2003,

The power cylinder has recently been upgraded and the engine is now using a unitized coil module. Cummings and Chrusciel said that the biggest technical change for the natural gas engine line is the launch of the new John Deere electronics-built ECU The new "full featured", ECU incorporates: a road speed governor; cruise control, auto resume; elevated high idle control, primarily for vehicles with air conditioning; in-cab idle adjustment; remote PTO; dual throttle, ABS with traction control; engine brake interlock with a decel light; foot pedal inhibit/ throttle interlock; a range of engine protection inputs for both derate and hard shutdown; pulse width modulation fan control; A/C input; coolant temperature input; throttle charge temperature; transmission sump temp; shutdown override switch; shutdown reset; and shutdown alarm.  The ECU is J1939 CAN and J1587 capable, Deere said.

Starting in 2000, Deere's 8.lL engine has been used in Freightliner FL 70 chassis as utility trucks operated by Pacific Gas & Electric, City of Oakland, and Southern California Gas.

The John Deere gaseous engine program began in 1996 with the application of Deere's first lean burn, closed loop, adaptive learn natural gas engines in a Blue Bird AR American 5chool bus chassis.  In 1999, ThorAas Built also began offering the 250 hp 8.1 L natural gas engine in its Saf-T-Liner bus chassis. Both are targeted primarily at school bus use in California.

The next step was smaller transit buses.  Deere had gained some natural gas engine experience in commercial uses in Blue Bird transit buses, though the majority of Blue Bird applications are in school buses.  The first significant program in small low-floor transit buses is the Moline MetroLink application mentioned above in ElDorado National's EZ-Rider, a heavy-duty 30 ft. low-floor transit bus, a 102 in. wide vehicle with seating for up to 29 passengers plus standees.

Next was a recent order from Sonoma (California) Transit for the same bus and engine configuration.  Cummings said five buses are due to enter service in Sonoma this year.  Blue Bird also introduced a new commercial bus, the model XCEL 102HF, at last month's American Public Transit Association Expo with the 250 hp 8.1 L engine as the standard CNG engine option.

A developing market, especially in California, for gaseous engines is refuse vehicles.  Deere's experience in this area goes back to a 1999 demonstration program with Waste Man- agement in Irvine, Calif., that involved four front-end loading Peterbift model 320 trucks repowered with the 280 hp 8.1 L engine.  Deere said the positive feedback received from this demonstration project resulted in the first production orders including the city of Santa Monica, Calif., a leader in the use of aftemative engines.

Deere has also made moves recently in the heavy-duty transit bus market.  "This is a market that requires you have 50,000 miles and/or two years of operating experience before you can get your foot in the door," Cummings said. 

To do that, Cummings said Deere identified "a couple of sophisticated, technologically advanced transit agencies that were currently using natural gas." The results were 280 hp model demonstration programs with Queens Surface Transit, Queens, N.Y, a two-year program with over 50,000 miles of operation in Orion V buses.

The second was with Metropolitan Atlanta Regional Transit (MAPTA) in Atlanta, Ga., a two-year demonstration program that totaled over 60,000 miles in repowered New Flyer buses.  "These two programs gave us the opportunity to prove our humidity compensation package and knock sensor," Cummings said. Both demonstration programs are now completed.

Cummings said two "production intent" heavy-duty transit programs are currently underway including five 40 ft. New Flyer buses using the new 280 hp rating that were expected to begin operation with Washington (D.C.) metro transit shortly.  John Deere Power Systems distributor Bell Power Systems, Inc., Essex, Conn., packaged the engines into the New Flyer buses for Washington Metro.  Bell has been very active in Deere natural gas repowering in a variety of mobile applications along the East Coast.

The second heavy transit application involves seven, 40 ft.  Orion V chassis, also using the 280 hp 8.1 L engine, for transit use in Auburn, Calif.

Two other 8.1 L/280 hp demonstration programs are underway with Ommitrans in San Bernardino, Calif., in New Flyer buses and with LA Metro Transit in Los Angeles.

One of the first non-bus markets to open up for Deere natural gas engines were utility trucks.  Starting in 2000, Deere's 250 hp model has been used in Freightliner FL 70 chassis as utility trucks operated by Pacific Gas & Electric, the city of Oakland, and Southern California Gas.

One of the more interesting markets for natural gas engines in general has been in the refuse market.  One of the most demanding applications for any type of powertrain component, refuse trucks are also one of the hot markets in California being targeted for possible conversion from diesel to natural gas engines.  Deere's experience in this area goes back to a 1999 demonstration program with Waste Management in Irvine, Calif., that involved four front-end loading Peterbilt model 320 trucks repowered with the 280 hp 8.1 L engine.  Cummings said the positive feedback received from this demonstration project resulted in the first production orders including the city of Santa Monica, Calif., a leader in the use of alternative engines.

Also, City of Industry (Calif.) Disposal recently put the first two 275-hp/800 lb.ft. Deere-powered Crane Carrier refuse trucks into fleet operation.  "That torque curve was specifically developed for refuse truck applications utilizing the Allison MD transmission," Chrusciel said.

"The refuse market is just beginning to take off," Chrusciel said.  "With Rule 1193 mandated in the greater Los Angeles area, everyone is dabbling, trying to figure out the best way to meet the mandates.

Deere and Crane Carrier have initiated a demonstration program with a low-cab-forward, front-end loader powered at the 280-hp/900 lb.ft. rating.  This demo will provide refuse fleets the operational feedback of our advanced technology, natural gas engine so they finalize their future purchasing plans." Further, Washington D.C. Department of Public Works has ordered two new Sterling Cargo refuse trucks with Leach 16-yard rear packer bodies.  Bell Power Systems will repower the trucks with Deere's 6081HFN engines.  Leach intends on marketing this product nationwide as an "American Fuel Vehicle" early next year.

Finally, the other market Deere natural gas engines have seen some interest is in city pick-up and delivery trucks.  The most visible of these programs is a repower by Bell Power Systems of 15 trucks at Manhattan Beer in New York City done with funds from a New York State grant.  That program, Cummings said, is serving as a demonstration program for future P&D truck applications. 

One of Deere's more highly visible gaseous engine programs is a repower by its Connecticut distributor, Bell Power Systems, of 15 trucks at Manhattan Beer in New York City, done with funds from a New York State grant. That program is serving as a demonstration program for future pick up and delivery truck applications.