SAE 912359 (Toronto 1991)

Laboratory and Field Experience with the Development of a Natural Gas Conversion for the Cummins N14 Engine Family.

Garcia, P.; Shiells, W.

Transport Fuel Systems (NZ) Limited

(A member of the Carter Holt Harvey Group of Companies)


A first retrofit conversion of a Cummins NTC335 engine to spark ignition was carried out in New Zealand in 1984. The conversion used widely available technology for stoichiometric control of natural gas fuel-air mixtures. Experience from the on-road application in a 40,000kg GVW truck contributed much to the later development of a 400hp gas-fuelled variant of the same engine family, using lean mixture carburettion control. A second engine entered service in a logging application in February 1989.

The following paper summarises results arising from laboratory testing of the second engine, and from in-field monitoring. Also presented are preliminary results from testing of a third generation engine, using timed multi-point injection of gas fuel.

You can request a full copy of this paper by sending mail to Pablo Garcia.

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