4307244 QSK60 Fuel Pump – High‑Altitude And Variable‑Load Optimised Power Unit

The QSK60 engine platform is deployed across a remarkable range of environments-from sea‑level marine applications to high‑altitude mining operations at over 4,500 metres. At elevation, the reduced air density changes the engine's combustion characteristics, requiring adjustments to the fuel delivery profile to maintain power output and emissions compliance. The 4307244 is a power unit assembly for the QSK60 fuel system, specifically optimised for high‑altitude and variable‑load applications. Unlike the standard 4307242 unit, the 4307244 features a revised pumping element geometry and a modified delivery valve characteristic that provides enhanced low‑speed torque response-a critical requirement for engines that frequently operate at partial loads or experience rapid load changes. This article provides a detailed technical overview of the 4307244, including its specific calibration differences, performance characteristics, application fitment, and installation requirements.

The 4307244 is not simply a standard power unit with a different part number. It incorporates specific design changes that address the unique challenges of high‑altitude and variable‑load operation:

Feature 1 – Revised Plunger Helix Profile:
The plunger helix has been re‑profiled to provide a more progressive fuel cutoff characteristic. This improves low‑speed torque response by allowing a slightly longer injection duration at low engine speeds-compensating for the reduced air density at altitude.

Feature 2 – Modified Delivery Valve:
The delivery valve incorporates a higher retraction volume (2.0 – 2.5 mm³) compared to the standard unit (1.5 – 2.0 mm³). This provides a more gradual pressure decay after injection, reducing nozzle after‑dribble and improving combustion stability during load transitions.

Feature 3 – Enhanced Low‑Speed Filling:
The inlet ports have been enlarged to improve low‑speed filling, ensuring consistent delivery during rapid acceleration events-critical for mining trucks climbing steep grades.

The 4307244's performance is verified on a calibrated test stand, with the following data points recorded on the accompanying test certificate:

Note: The peak torque delivery is approximately 4% higher at 1,000 rpm compared to the standard unit, compensating for the reduced air density at altitude.

The 4307244 is the factory‑specified power unit for QSK60 engines operating in:

High‑altitude mining (above 3,000 metres)

Variable‑load applications (frequent load changes, e.g., shovel loading cycles)

Marine auxiliary engines with rapid load changes

Oil and gas pump drives with variable‑speed operation

Typical equipment examples:

Important: The 4307244 is not recommended for engines operating exclusively at sea level with constant high loads (e.g., power generation baseload). In those applications, the standard 4307242 provides optimal performance and fuel economy.

Plunger and Barrel Assembly (Altitude‑Optimised):

Delivery Valve Assembly (High‑Retraction Variant):

Inlet Check Valve (Enlarged Port):

Q1: How do I know if my QSK60 engine requires the 4307244 instead of the standard 4307242?
A: Check the engine's build specification-it will be listed on the engine data plate or in the service documentation. Engines with the "High Altitude" or "Variable Load" option code will specify the 4307244. Alternatively, consult the engine's original calibration file.

Q2: Can I install the 4307244 in a sea‑level engine to improve low‑speed torque?
A: Yes, but it requires ECU recalibration to the 4307244‑specific fuel map. Without recalibration, the engine will run rich at low speeds, causing increased fuel consumption and higher particulate emissions. We recommend this upgrade only for engines that genuinely need the improved low‑speed response.

Q3: What is the service life of the 4307244 under high‑altitude mining conditions?
A: Under typical high‑altitude mining conditions (continuous high load, variable speed, 2,200 bar rail pressure), the power unit typically lasts 8,000–10,000 hours. The altitude‑optimised design does not sacrifice durability-the same high‑grade materials and manufacturing processes are used.

Q4: Does the 4307244 require different fuel filters or maintenance procedures?
A: No-the same fuel filters and maintenance intervals apply. The 4307244 has the same external dimensions and connection points as the standard unit, so all existing plumbing and filtration components are compatible.

Q5: Can I convert a 4307242 to a 4307244 by changing the pumping elements?
A: The pumping elements and delivery valves are different, but the pump body is the same. You would need to replace the plunger‑barrel sets, the delivery valves, and the inlet check valves. However, the complete power unit replacement is more cost‑effective than a component‑level conversion.

Q6: How do I verify that the ECU calibration matches the 4307244 after installation?
A: Use diagnostic software to check the calibration ID-it should match the number listed in the engine service documentation for the 4307244. If the ID does not match, the ECU must be re‑flashed with the correct calibration file.