A driver heads for his cab, jumps in, belts up and hits the starter button. It’s only 10 degrees outside, but the engine fires almost immediately, and runs quietly while he warms it up. No fuel heaters are in use. Nobody has added any anti-gel to the fuel tank. As the day wears on, he drives peacefully, believing that the chance of getting any engine codes relating to the emission systems on his tractor are unusually low.Get more news about truck engine,you can vist our website!

The same morning at the fleet’s accounting office, the staff looks over its fuel cost records, noting a measurable reduction in fuel costs although no large changes have occurred in where they run — just the purchase of a few new tractors.

Welcome to the not-so-messy middle. Changes such as these are likely to come to fleets that begin specifying natural gas-fueled tractors..By the middle of next year, Cummins will be offering a full-size truck engine that runs on natural gas called the X15N. Cummins Inc. has been a pioneer in providing spark-ignited natural gas engines for trucks beginning with the ISX12N engine, originally modified by Westport Fuel Systems to run on natural gas. Cummins and Westport established a joint venture that provided the system for Cummins engines, and the engine manufacturer now owns that venture and its patents.

“This is the first engine on the next-generation X15 fuel-agnostic platform. Diesel and hydrogen will follow later,” said David King, Cummins’ North American on-highway product manager, natural and renewable gas engines. He explained that the new platform provides internal parts that are common below the head gasket. “The natural gas engine will have a unique cylinder head for the necessary cooling, a spark ignition system, etc.” The new engine has advanced, leaned-out architecture, he added.

The X15N engine is a technological tour de force that combines some of the best of today’s truck diesel technology with user-friendly combustion and emissions technology similar to what is seen in the gasoline engine used in passenger cars. While Westport has an interesting natural gas system called HPDI (high-pressure direct injection) that works more like a diesel, Cummins has adopted a system that, according to King, “is spark ignited with an inductive ignition system,” which means ordinary spark coils and spark plugs like cars have — and a far simpler aftertreatment system than we see on diesels.

Fuel will be injected at a single point after the intake throttle through the use of a multi-solenoid metered fuel manifold system,” he said.

Like in an automotive fuel injection system, the engine’s ECM will calculate the volume of fuel needed to match airflow through sensor inputs that measure factors like the throttle position, engine RPM and turbo boost pressure. The system is actually simpler than modern automotive fuel injection because gas is a vapor, thus mixing with perfect uniformity with intake air when introduced at a single point.

Unlike the HPDI system or a diesel, this system relies largely on the extremely high knock resistance (octane) of natural gas to allow a high enough compression factor for efficiency and power. Gas’s natural resistance to knock is augmented via the use of jacket-water cooled EGR, allowing the engine’s power, torque and efficiency to be maxed out the way diesel power is — with turbocharging and charge-air cooling, so much of the basic architecture of the engine will be familiar. Because the engine will have a lower compression ratio than a diesel (at 12:1), it will be slightly less efficient. However, it’s obvious some serious advanced engineering went into getting the same 1,850 pound-feet of peak torque from this engine as we see in the highest-­rated X15 Efficiency Series diesel.