In the medium- and heavy-duty commercial vehicle, large bus, and construction machinery sectors, the Cummins ISL series of engines has always played a pivotal role. Since its introduction, this 8.9-liter inline-six diesel engine has earned widespread recognition from customers worldwide for its lightweight design and powerful output. Weighing just over 700 kilograms, the ISL engine boasts the highest power-to-weight ratio in its class, with power output ranging from 280 to 400 horsepower and peak torque reaching up to 1,250 pound-feet. Whether during the frequent stop-and-go operation of city buses or the sustained, heavy-duty operation of long-haul freight transport, the ISL engine has demonstrated exceptional reliability and durability. However, even the most robust machinery cannot withstand the relentless wear and tear of time and the continuous strain of heavy-duty operations. Power loss, rising fuel consumption, difficult starts, and excessive emissions—once these “age-related ailments” set in, equipment managers face a dilemma: spend a fortune on a new engine, or put up with the declining performance and continue to make do. Keluo has offered a third option—a practical path that truly revitalizes ISL engines.
The fundamental reason why ISL engines are worth overhauling rather than simply scrapping lies in their solid technical foundation and forward-thinking design philosophy. This engine features an integrated cylinder block and fuel system design, a high-strength forged steel crankshaft, highly durable pistons, and cylinder liners with special surface treatments. The XPI high-pressure common-rail fuel system, derived from the ISX15 heavy-duty engine, delivers injection pressures as high as 1,800 bar, enabling extremely precise control over injection timing and fuel delivery. The variable-geometry turbocharger provides excellent power response and driving performance across the entire RPM range, while also serving as an exhaust brake. A closed-crankcase ventilation system manages blow-by gases, while a nanotechnology-based fuel filter removes 98.7% of particles as small as 4 micrometers. Together, these technical features ensure that the ISL engine maintains outstanding reliability even under high-load, high-intensity operating conditions, with an overhaul durability target of 850,000 kilometers. It is also worth noting that the ISL engine employs a replaceable wet-sleeve design, a detail of great significance for overhaul and remanufacturing—the cylinder block itself does not need to be scrapped entirely due to cylinder bore wear; simply replacing the cylinder liners restores bore precision, significantly reducing overhaul costs and enhancing the economic viability of remanufacturing.
Keluo’s overhaul service for ISL engines goes beyond simply replacing a few wear-and-tear parts; it is a complete, systematic remanufacturing process. Every ISL engine sent to Keluo’s workshop undergoes thorough disassembly and deep cleaning. Technicians then use specialized testing equipment to perform comprehensive dimensional measurements and non-destructive testing on core components such as the cylinder block, crankshaft, camshaft, and connecting rods, scientifically determining which parts can remain in service and which must be replaced. Thanks to the ISL engine’s wet-liner design, cylinder block remanufacturing is both feasible and cost-effective—replacing cylinder liners, reassembling piston ring sets, precision-honing crankshaft journals, and installing new bearing shells. This series of repair procedures strictly adheres to Cummins’ original factory technical standards. The fuel injection system undergoes fine-tuning on a calibration bench to ensure optimal matching of injection pressure and fuel delivery. All seals, gaskets, and filters are replaced with new ones, while the turbocharger is either repaired or replaced based on its actual wear condition. After assembly, the ISL engine undergoes multi-stage load testing and performance verification on a dedicated test bench. Power output, fuel consumption, cylinder pressure balance, and operational smoothness—every metric must meet the required standards before the engine is released for delivery.
The returns from this rigorous remanufacturing process are tangible. Keluo’s remanufactured ISL engines perform nearly as well as new engines, with both power output and fuel economy restored to ideal levels, while the procurement cost is only 50 to 60 percent of that of a brand-new engine. Compared to overhauls performed by ordinary repair shops, Keluo’s remanufactured ISL engines have a lower failure rate and a longer service life, reaching more than 80 percent of a new engine’s lifespan. Delivery times have been reduced to one to seven days, minimizing equipment downtime. In addition to fully overhauled engine assemblies, Keluo supplies a full range of ISL OEM-grade parts—including cylinder heads, crankshafts, camshafts, water pumps, oil seals,gaskets, filters, piston rings, and cylinder liners—truly enabling “one-stop” procurement of engines and parts. From heavy-duty trucks to city buses, from concrete mixers to oilfield logging equipment, and from tour buses to emergency vehicles, remanufactured ISL engines deliver stable and reliable power output.
Choosing Keluo’s ISL overhaul service means more than just acquiring a refurbished engine; it means selecting a comprehensive power solution centered on the entire lifecycle management of your equipment. Pre-sales technical consultations help customers precisely match engine models to operational requirements, while a comprehensive after-sales service system responds promptly to fault resolution and maintenance inquiries. Overhauled engines come with a clear warranty commitment. Keluo fully understands the significant losses caused by equipment downtime and has therefore established a rapid-response mechanism to ensure timely technical support. The core value of this service lies in significantly extending the service life of ISL engines and enhancing the return on equipment investment at a cost far lower than that of new engines, enabling every ISL engine to continuously deliver powerful performance in its respective application scenarios.
Hebei Keluo Construction Machinery Co., Ltd. is a large-scale construction machinery manufacturing group integrating R&D, production, and service. Headquartered in Shijiazhuang, Hebei Province, the company occupies an area of approximately 133,000 square meters and employs over 300 people. With over two decades of deep expertise in the construction machinery engine sector, the company specializes in supplying new and used construction machinery, engines, and spare parts, with an annual production capacity exceeding 8,000 new and remanufactured engines. Its products are exported to numerous countries worldwide, and it has established a comprehensive overseas dealer network. Over the past five years, the Keluo brand has consistently ranked among the top three in market share for engine exports. Keluo has always adhered to a quality-first philosophy, providing reliable remanufactured engines and supporting components to help ensure the efficient operation of customers’ equipment. Upholding a service philosophy of professionalism, pragmatism, and reliability, Keluo will continue to leverage its leading remanufacturing technology and comprehensive supply chain system to provide cost-effective power solutions for global customers, ensuring that the ISL engine—the benchmark for medium- and heavy-duty power—continues to shine.
