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  • Cummins QST30; Rugged Twelve-Cylinder Workhorse

Cummins QST30; Rugged Twelve-Cylinder Workhorse

1,200hp V-12 Workhorse Is More Than Ready for the World’s Toughest Jobs

John Lehenbauer
Feb 5, 2019
Photographers: Courtesy of Manufacturer
Diesel engines have been the unsung workhorses of progress for more than 100 years. They provide the power needed to keep lights on, move cargo, and churn the earth to provide us with daily necessities. Industrial diesels of every size, shape, and displacement are found inside power generators, tractors, ships, trains, forklifts, and a multitude of other vehicles and equipment. These engines are built to handle intense demands and run continuously for hours—sometimes days.
Cummins understands how stout a diesel engine must be to meet all the demands that may be placed on it. So, when engineers developed the 12-cylinder QST30 for mining applications, they took into consideration everything the end user is looking for, like the ability to custom-tailor it to equipment, work environment, and job demands. Yet the powerplant still has to provide improved fuel economy, reliability, durability, and meet US EPA Tier 2 and EU Stage II emissions standards so it can be used in such things as haul trucks, blast-hole drills, and wheel loaders all over the world.
Photo 2/3   |   The Cummins QST30 produces a healthy 1,200 hp and 3,700 lb-ft of torque. Two high-efficiency wastegate turbochargers use water-cooled housings and titanium impellers to ensure a long service life. The turbos are mounted on the top of the engine to help with equipment integration along with easing service and repair.
Constructing a strong engine like the QST30 requires a good foundation. So, Cummins starts with a one-piece, cast-iron 50-degree V-style block with wide cylinder spacing for durability and ease of servicing. Hardened cylinder liners are pressed into the block then filled with one-piece ferrous cast-ductile-iron pistons. Using ductile iron guarantees the pistons can withstand the stress of high internal pressures and provide the durability needed for a long life. The piston bowls are designed with a recontoured shape to improve combustion. In order to keep piston temperatures under control and extend their life expectancy, a cooling nozzle provides a steady stream of oil to the underside of each one. Pistons are connected to a forged-steel crankshaft via forged connecting rods.
The QST30’s cylinder heads use a swirl-port design for durability and optimized combustion sealing. Each head has two Nitride-coated intake and two exhaust valves (with stelite facing) per cylinder. The enhanced airflow helps increase low-end torque and reduce emissions output. Dual high-efficiency wastegate turbochargers are mounted on the top of the engine. The turbos feature water-cooled housings and titanium impellers, which help ensure their longevity.
Modern low-emissions, high-horsepower engines like the QST30 use high-pressure, common-rail fuel systems. Two Bosch RP39 fuel pumps provide the necessary amount of fuel and correct injection pressure. The injector nozzles have an optimized spray pattern that helps facilitate a proper mixture of fuel and air. High-flow electric lift pumps eliminate the need for manual priming of the system and promote quicker, more reliable starts.
Photo 3/3   |   A Bosch RP39 injection pump is mounted on each side of the engine. The two units provide an abundance of high-pressure fuel to the injectors.
Like most modern engines, electronics play an important part in an engine’s ability to function. Cummins’ Quantum System Electronics is a high-speed electronic control module that’s isolated from vibration, uses a self-cooling mount, and has a fully sealed wiring harness with fail-safe connectors. Quantum System integrates the ECM with the engine’s sensors to optimize combustion and overall performance, data monitoring, and protection. The unit’s ruggedness is ideal for mining operations for which down time is at a minimum.
To reduce the amount of wear that occurs during startup, the QST30 uses a prelube system that distributes oil to rifles and friction surfaces while building oil pressure before cranking starts. Pressure switches help reduce the chance of starting the engine dry. The engine’s two-stage oil filter combines full-flow and bypass filtration to remove harmful sludge and up to three times as many contaminants as other systems to reduce engine wear. This is very important for QST30s that spend an entire lifetime working in dirty conditions like mines.

SPECIFICATIONS

Engine: Cummins QST30
Displacement: 30.5L (1,861 ci)
Engine Layout: V-12
Valvetrain: 48-valve
Bore x Stroke: 5.51 x 6.50 inches (140 x 165 mm)
Compression Ratio: 14:1
Head material: Cast-iron
Block material: Cast-iron
Piston material: Cast ductile iron
Power: 1,200 hp (679 kw)
Torque: 3,750 lb-ft (4,100 Nm)
Emissions: EPA Tier 2, EU Stage II
Induction: Two wastegate turbochargers
Exhaust: Cast-iron
Intercooler: Air-to-air
Cooling System: Liquid-cooled
Fuel System: Common-rail direct-injection
Lubrication System: Wet sump
Lubrication Capacity: 156 quarts (148 liters)
Dry Weight: 7,337 pounds
Length: 74.3 inches (1,905 mm)
Width: 58.4 inches (1,483 mm)
Height: 68.8 inches (1,744 mm)

Sources

Cummins
Columbus, IN 47202
800-343-7357
https://www.cumminsengines.com/repower
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