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The new 3.0-L DieselMax 4-cylinder develops 74 hp and, at 295 lb·ft, as much peak torque as the company's 4.4-L diesel (Image: JCB).

JCB’s new 3L DieselMax: Tier 4 without SCR

Off-highway powertrain and driveline specialist JCB said at Conexpo 2017 the company is starting production of its new entry-level engine, the 3.0-L DieselMax, with its first applications in OEM machines coming in the U.S. market later in 2017.

Alan Tolley, group director—engines at JCB Power Systems, said DieselMax’s key design feature is that it produces the industry-standard 74-hp (55-kW) rating while complying with U.S. EPA Tier 4 emissions standards without selective catalytic reduction (SCR) exhaust aftertreatment, a boon for reducing operating cost and maintenance complexity.

The Dieselmax 4-cylinder also is 25% smaller than JCB’s 4.4-L EcoMax diesel, until now the company’s smallest-displacement Tier 4-compliant engine. The new 3L also is roughly 30% lighter than the 4.4-L engine—and as much as 8% more fuel-efficient, Tolley told Truck & Off-Highway Engineering during an interview an Conexpo. And the DieselMax may be significantly smaller than the 4.4-L, but generates the same torque rating of 295 lb·ft (400 N·m).

“We’ve very much taken the (JCB) heavy-duty architecture into this design,” Tolley said in noting the new engine’s design priorities of durability and low service requirements. The oil-change interval can extend to 1000 hours, matching the fuel-filter change schedule and hydraulic tappets mean no periodic valve adjustments. There also is an electronically-controlled turbocharger wastegate and glowplugs for quickly achieving a temperature conducive to smooth operation, quiet operation.

“What the end user gets is less fuel consumption, low noise and longer service intervals,” Tolley said of the Dieselmax, which will be suitable for OEMs to specify for all manner of backhoes, loaders, excavators and other construction equipment.

High tech for the sweet spot

Tolley said engines with a maximum output of 55 kW now play a significant role in the market because of the latest emissions standards in the U.S. and Europe.

“55-kW is getting very popular,” he said. “Above that, you need SCR (for Tier 4 and Euro Stage IIIB emissions compliance).” He said there has been pushback in some regions or by some operators regarding engines that require SCR. There is a comfort level with SCR that varies by region, machine type and duty cycle, he said. Rental operations, for example, are averse to SCR because of maintenance concerns.

The DieselMax also has cooled EGR and common-rail fueling and is capable of accommodating stop-start operation. He said it would be possible to use a variable-geometry turbocharger, but it is not needed to achieve the 55 kW rating. Tolley said the engine could be tuned for more output, but since that would require fitment of SCR, there wouldn’t be much sense in using a more-sophisticated turbocharger.

He added that the engine’s operating characteristics provide more than enough power for most equipment that would use the engine. Maximum power is developed at 1200-1250 rpm and peak torque is available almost throughout the DieselMax’s operating range.

The new DieselMax is built by JCB at its assembly plant in Darby, United Kingdom.

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