Diesel Developments
New compact engines share the spotlight with their big-bore brethren
By Russell A. Carter, Managing Editor

Think “mining diesel,” and generally what comes to mind is an eight-ton, 16- or 20-cylinder, twin-turbo’d beast bellowing under the strain of a 360-ton payload. But the reality is that there are many more medium- and small-sized diesel engines at work in mines, powering drills, utility vehicles, pumps, generators and other equipment.
The large mining-class diesel engine segment—750 hp (560 kW) and up—has drawn a lot of attention in recent years as the industry’s demands for greater loading and haulage capacity escalated while engine builders were wrestling with decisions on which design path(s) to follow in order to meet upcoming off-highway emissions and low-sulphur fuel regulations—new engine platform with a clear avenue to future performance demands, or tweaking of a proven design to assure worried customers and avoid OEM/repower installation problems?
The real pressure, however, has been on the mid-range (50–750 hp/37–560 kW) engine class. As U.S. Environmental Protection Agency (EPA) and European Union regulations were phased in for off-road diesels in various horsepower ratings starting in 2001, these gradually more stringent standards imposed restrictions for NOx and particulate emissions on small- and medium- power diesels that generally didn’t apply to high-horsepower off-road diesels until later in the regulatory timetable. On top of that, a consent decree agreement with the EPA required certain manufacturers to meet the EPA’s Tier 3 standards for off-highway engines in 2005—a year earlier than the rules stipulated.
The result has been a flurry of new engine introductions over the past year or so, mostly in the mid-power range as engine suppliers brought out their Tier 3/Stage IIIA compliant models, but also extending to the larger mining-class engines as well as compact units.
More recently, a court decision denying an industry-backed petition for review of the U.S. Mine Safety and Health Administration’s proposed rule on diesel particulate matter (DPM) found that DPM presents a significant risk to the health and safety of underground miners, thus focusing even more scrutiny on the emissions performance of the smaller diesels commonly used in underground applications.

Volvo has applied its new V-ACT system for improved combustion and Tier 3 / Stage IIIA
emissions compliance to diesels ranging from 6 to 16 liters displacement.

Four from Volvo
Volvo is offering a quartet of diesel engines equipped with its V-ACT system for improving combustion efficiency and lowering emissions. The four models, all EPA Tier 3/EU Stage IIIA compliant, include the:
• D7E, a 7.2-liter,
188–250 hp inline 6- cylinder, two-valve-per-cylinder engine with common rail fuel injection and EMS 2 engine management system;
• D9B, a 9.4-liter, 271–343 hp inline 6- cylinder, four-valve-per-cylinder model with EMS 2, camshaft-driven high-pressure unit injectors and turbocharger;
• D12D, a 12.1-liter, 269–426 hp, inline 6-cylinder with features similar to the D9B; and the
• D16E, a 16.1-liter, 471–540 hp engine, also equipped similarly to the D12D and D9B.
In brief, the V-ACT system employs advanced fuel injection, more effective air flow and enhanced engine management. In order to lower nitrogen oxide (NOx) emissions, Volvo has equipped some of its off-highway engines with a patented, switchable Internal Exhaust Gas Recirculation (I-EGR) function: On the D9B and D12D engines, the exhaust rocker arm is fitted with a “double rocker” device that allows for a small second opening of the exhaust valve, from which a controlled amount of exhaust gas is fed back into the cylinder during the inlet stroke to lower peak combustion temperature. This is possible, according to Volvo, because the pressure pulses in the exhaust are higher than the in-cylinder pressure during a portion of the combustion process. The switchable I-EGR is electronically controlled by the EMS 2 engine management system, while activation of the double rocker device is through the engine’s oil pressure system. I-EGR is engaged only at high engine speeds and loads; at lower speeds it is switched off. The D16E engine also features the double-rocker, but with an extra, or third, rocker arm in parallel to the exhaust rocker arm. On the D6E/D7E engines, the I-EGR feature is hydromechanically actuated.

Other V-ACT features include Volvo’s latest-generation engine electronic control unit (E-ECU) with enhanced software, which works in concert with the EMS 2 management system for complete control of all engine functions; new-generation, high-pressure unit injectors for improved fuel metering; a turbocharger and air-to-air intercooler with improved flow characteristics and larger capacity; and new steel/aluminum pistons for more uniform piston temperature, less piston play and more efficient combustion.
Volvo claims that with the V-ACT system installed, low sulphur fuel is not required (as it is for cooled EGR), and low or ultra low sulphur fuel can be used without adverse effects. It also claims lower maintenance costs, when compared with external EGT—due to less sulphuric acid buildup—and overall, allows the company to meet emissions and performance objectives on a proven engine platform without turning to overly complex solutions.

Caterpillar’s new C175 engines will replace the 3500 series.

Compact CATs
Over the past year or so, new diesel rollouts from Caterpillar have covered both ends of the size spectrum. Last spring, Cat unveiled the heavyweight C175 engine as part of its program for development of electric-drive haul trucks (E&MJ, May 2006, p. 54, “Cat Plugs In to AC Electric Drive Technology”). The C175 will be rated at 2,000 to 4,000 hp in mining applications, meets EPA Tier 2 emission standards, and will serve as the platform for achieving more stringent Tier 4 standards (diesel engines rated at more than 700 hp are exempt from Tier 3 regulations). Displacing 5.3 liters per cylinder, engines in the C175 family will be offered in 12-, 16- and 20-cylinder versions with total displacement of 64, 84 and 106 liters, respectively.
C175 engines will replace Cat’s 3500 series, introduced in 1985, and the company said they will provide a number of advantages over the older models including higher power density, a longer enginerebuild life, lower sound levels, improved altitude capability and better fuel consumption. The new engines will begin to appear in the company’s mining truck lineup after field testing is completed.
Cat’s latest product line additions, however, are in the form of three new compact diesel models. The C1.5, C1.7, and C2.2, available in naturally aspirated, turbocharged and turbocharged aftercooled versions, join five previously-announced engines in Cat’s compact diesel line-up.
“Caterpillar is committed to the compact diesel market,” said Caterpillar Marketing Manager Mike Reinhart. “And these three new engines are the latest step in fulfilling that commitment. Cat compact diesels now cover the range from 11 to 80.5 hp (8.2 to 60 kW) with eight engines that meet existing Tier 3/Stage IIIA emission standards for North America and Europe and are designed as solid core engine platforms to tackle future emissions requirements.”
The complete Cat compact diesel product line now includes the:
• C0.5, rated from 11 to 13.7 hp (8.2 - 10.2 kW) at 2,800 – 3,600 rpm;
• C0.7, rated from 16.4 to 20.5 hp (12.2 - 15.3 kW) at 2,800 – 3,600 rpm;
• C1.1, rated from 18.4 to 28.2 hp (13.7 - 21 kW) at 2,200 – 3,400 rpm;
• C1.5, rated from 27.8 to 40.2 hp (20.7 - 30 kW) at 2,200 – 3,000 rpm;
• C1.6, rated at 33-35.5 hp (24.6 - 26.5 kW) at 2,800 – 3,000 rpm
• C1.7, rated at 33.2 to 34.8 hp (24.7 - 26 kW) at 2,400 – 2,600 rpm;
• C2.2, rated from 41.6 to 66 hp (31 - 49.2 kW) at 2,200 – 3,000 rpm; and
• C3.4, rated from 57.6 to 80.5 hp (43 - 60 kW) at 2,600 rpm.
All of the engines in Cat’s compact diesel lineup offer 500-hour maintenance intervals and single-side service access that are designed to reduce the total cost of ownership. According to Reinhart, “They’re light, compact, quiet, and very flexible in terms of packaging and configuration. Most of them offer a choice of high or low mounted fans, special low-noise fans, and advanced electronic governors which extend engine life in many applications.”

In addition to the twin-turbo version of its QSK60 engine shown here, Cummins has developed a
single-turbo version suitable for operation in mining applications up to 3,000 m elevation.

Cummins Covers Tier 2
Cummins Inc. launched its Tier 2-certified QSK38 engine in October 2006. The QSK38 engine, rated at 900-1,500 hp (671-1,119 kW), provides up to 4,570 lbft (6,197 Nm) of torque at 1,000 rpm, and offers a high torque reserve with a torque rise of more than 12%, according to the company. The engine shares 70% of its parts with the KV 38-liter base engine.
The QSK38 features Cummins’ Modular Common Rail fuel system, providing fullauthority electronic control over fuel timing, quantity, pressure and delivery rate shape. Precision control over the number of injection “events” enables enhanced performance and reduced engine noise as well as emissions compliance. Cummins said it has been able to optimize the in-cylinder combustion system to meet Tier 2 NOx levels without increasing displacement or making significant configuration changes.
The QSK38 also has single-piece FCD pistons suited for high cylinder pressures and increased power output, contributing to what Cummins says is a 10%-plus increase in life-to-overhaul.
At bauma 2007, Cummins will display an enhanced version of its Tier 2-complient QSK60 diesel for mining applications up to 3,000 m elevation. This engine is rated at 1,782-2,700 hp (1,389–2,014 kW) in a single-stage turbocharger configuration. Previously, ratings above 2,500 hp (1,865 kW) were only available in a two-stage configuration.

Deutz’s 2015 series V-8 diesel is designed with four valves per cylinder and the company’s
MVS solenoid-controlled injection system.

Deutz’s Water-Cooled Models are Hot
Deutz AG’s diesel products are divided into two segments: compact engines and Deutz Power Systems. Much of the company’s recent activity has been focused on additions and improvements to its compact engine products.
The compact engine line comprises air, oil and water-cooled diesels in several series ranging up to 500 kW. In 2005, Deutz sold about 200,000 engines and increased sales by a double-digit percentage in 2006. This increase, according to the company, was mainly attributable to higher demand for its liquid-cooled engines in the 4-liter or smaller range.
The company’s 2008 series engines are naturally aspirated units with three or four cylinders, rated at 20 or 27 kW. The 2009 series are available as naturally aspirated, three- or four-cylinder units plus a turbocharged four-cylinder model. Maximum power ranges from 28 to 50 kW.
Soon to join the product lineup in the lower power range are turbocharged fourcylinder engines in the new 2010 series, displacing 3.5 liters and with power ratings up to 74.9 kW. The engines are equipped with direct fuel injection and a mechanical governor as standard equipment. An electronic engine governor will be available as an option. The engines will be field-tested in 2007 and production is scheduled to start in the second half of 2008.
Deutz also announced development of a water-cooled four-cylinder version in the popular 2011 series, which heretofore had included only oil-cooled versions. The water-cooled engines will go into production later this year.
In the medium power class Deutz offers, in addition to the air-cooled 914 series, the water-cooled 2012 and 2013 series, available in four- or six-cylinder models with power ranging from 60 to 243 kW. All the above series meet EU Stage IIIA and EPA Tier 3 exhaust emission regulations.
Deutz notes that its engines are designed to provide power takeoff from the crankshaft front as well as from auxiliary power takeoffs via the gear train.
The 2012 and 2013 series engines also offer three additional power takeoff options for pumps and compressors via the gear train. In the higher power range, Deutz supplies air and water-cooled V engines in several series. The air-cooled 413 and 513 series engines have ratings of 77 to 405 kW, in naturally aspirated or turbocharged versions, with or without charge air cooling and in six-, eight-, 10- or 12-cylinder configuration.
The water-cooled 1015 and 2015 series top the company’s compact engine range. The six- and eight-cylinder V-engines are rated from 240 to 500 kW, offer high torque rise performance, and feature four-valve cylinder head technology and the Deutz MVS solenoid valve system.
Deutz has developed DVERT (Deutz Variable Emisions Reduction Technology), a mix-and-match modular system designed to reduce both noise and exhaust emissions generated by its compact diesels rated up to 500 kW. At the lower end of its power range, Deutz prefers to equip engines up to 100 kW with mechanical fuel injection and internal or external uncontrolled exhaust gas recirculation (EGR). Although these engines will not come standard with electronic controls, Deutz said they can be converted to electronic engine management by adding its EMR electronic engine governor.
In the 100–250 kW range, Deutz will offer both mechanical and electronically controlled high-pressure fuel injection systems, including its PLD inline injection pumps as well as its DCR common-rail injection system—both combined with controlled EGR. Different levels of system sophistication will be offered based on torque shaping, transient performance and power demands for a specific application.
Above 250 kW, Deutz will offer the MVS system—a combination of a PLD injection system with a solenoid-controlled injection valve. However, all higher- range engines equipped with DCR or MVS are easily adaptable to electronic engine management, according to the company.
Deutz also notes that engines equipped with DCR common-rail fuel system have the same basic shape as those equipped with mechanical injection systems— a plus for OEMs and for repower specialists. For example, the DCR features two feed-pump elements that have been integrated into the crankcase where they are driven by the camshaft, similarly to the single injection pumps of Tier 2 engines. This approach avoided any design changes to the crankcase.

DDC/MTU’s Gen-Set Giant
DDC/MTU Power Generation introduced a new version of its Series 4000 diesel engines for standby and prime power genset applications. The engines will be available in 12-, 16- and 20-cylinder, 90° V-configurations for 50- and 60-Hz applications. Depending on cylinder configurations, the new models will produce 1,750 kW, 2,250 kW or 3,250 kW. Overall, power performance has been increased by 13% for 16-cylinder and 16% for 12- and 20-cylinder engines over the previous versions. The 20V- 4000, now producing 3,250 kW, continues to be the largest output single engine high speed generator available, according to the company.
To meet the more stringent demands of EPA Tier 2 emission specifications, the new Series 4000 engines utilize internal engine technology, with new combustion balance providing reduced NOx emissions and significant decreases in particulates without exhaust aftertreatment, no sacrifice in power or fuel consumption, and a more compact footprint than their predecessors.

The latest generation of MTU’s electronic management system, ADEC (Advanced Diesel Engine Control), has triple injection electronics which provide optimum control of the fuel injection process to ensure low-pollution and high-efficiency combustion. Additionally, the ADEC system allows remote scanning and on-line display of engine data. For maintenance purposes, the data can be copied to another engine governor and when combined with MTU’s SAM (Service and Application Module) control unit, integration of MTU engines into a complete generation plant is streamlined.

Name, Please The former off-highway division of Detroit Diesel Corp. was renamed MTU Detroit Diesel in 2005. It was spun off as an independent company in 2006, and now serves as the North American regional division of MTU. MTU Friedrichshafen is the central company in MTU, and also the oldest. Tognum is the holding company that owns MTU and other companies including L’Orange, MDE, Mercedes-Benz Industrial Engines, CFC Solutions and the MTU Drive Shafts Division.

Scania Keeps it Simple
Scania Industrial & Marine Engines now can offer a complete range of 9-, 12- and 16-liter industrial engines that comply with EU Stage IIIA and EPA Tier 3 emissions standards.
“With our customers’ demand for compact engines in mind, we decided at an early stage to focus on further improving the combustion process itself, and thereby avoiding add-on systems like EGR and SCR,” explained Sales Manager Yngve Skog. A major advantage in the development, said Skog, was Scania’s modular engine design. The fact that the majority of engines share components such as cylinder heads, pistons, camshafts, unit injectors and other components made it possible to concentrate on further refining a limited number of components.
Scania engines are equipped with Scania’s proprietary Engine Management System, which monitors and processes thousands of pieces of engine data per second and evaluates the information to adjust injection timing and the amount of fuel injected to ensure optimum combustion and fuel economy in relation to operating conditions. It also makes it possible to program each individual engine to meet customers’ specific demands for engine revs and workload.
The company’s current lineup encompasses three turbocharged, charge-cooled, four-stroke diesels, including the DC9 EMS, an inline 5-cylinder model displacing 8.9 liters and generating 177–243 kW at 2,200 rpm; the DC12 EMS, a 6-cylinder inline model displacing 11.7 liters and rated at 257–331 kW; and the DC16 EMS, a 90° V-8, 15.6-liter engine rated at 353–382 kW. Last year was a record sales year for Scania, which sold more than 6,000 of its industrial and marine engines. The company’s strategy for continued growth is aggressive, targeting 10,000 engines by 2010.
“The greatest potential in terms of volumes and profitability can be found in those segments where operators demand reliable engines that combine high availability and performance with low lifecycle costs,” says Robert Sobocki, senior vice president and head of Scania Industrial & Marine Engines.
Scania claims a strong presence in the gen-set market. According to Sobocki, “The market for engines to drive emergency power-supply units is characterized by high price-sensitivity and low demand for parts. That is why Scania is focusing primarily on increasing sales to manufacturers of gen-sets for permanent electricity supply and for rentals, where the demands on engine performance and operating economy are higher.”
Scania’s strategy for doubling sales of industrial and marine engines includes reinforcing the company’s own sales and service network and continuing cooperation with specialized dealers.