Cylinder Head Compatible with PC22MR-2/PC26MR-3 3TNV76

Cylinder Head Compatible with PC22MR-2/PC26MR-3 3TNV76 Engines Those in the mini excavator repair and equipment rental industry have often encountered these seemingly intractable problems: engine coolant temperature spikes after continuous operation on construction sites, weak idling with blue-white smoke, frequent cylinder head gasket leaks and blow-by, and cylinder head deformation and cracking within a thousand hours of disassembly and reassembly. This is especially true for the 3TNV76 three-cylinder Yanmar engine in the Komatsu PC22MR-2 and PC26MR-3 models. Due to their compact size and limited operating space, the cylinder head is subjected to high-frequency thermal shock and heavy load pressure for extended periods. Inferior aftermarket parts can only provide temporary fixes, and repeated disassembly and reassembly delay work schedules and increase maintenance costs.

Most cylinder head descriptions on the market simply list part numbers, materials, and compatible models, neglecting the specific operating conditions required for mini excavators. The Komatsu PC22MR-2 and PC26MR-3 are 2-3 ton tailless mini excavators, primarily used for indoor demolition, municipal trenching, landscaping renovations, and backfilling in confined spaces. These machines operate under extreme conditions, directly testing the overall performance of the cylinder head:

1. Poor heat dissipation in a confined space: The compact machine body and insufficient ventilation in the engine compartment, coupled with prolonged idling and low-speed heavy-load operation, result in consistently high combustion chamber temperatures. Insufficient cooling efficiency in the cylinder head's water channels easily leads to thermal deformation.

2. Extremely high start-stop frequency: Frequent start-stop operations in landscaping and home improvement sites generate continuous thermal stress due to alternating hot and cold temperatures. Ordinary castings are prone to water channel cracks and valve seat loosening.

3. Large load fluctuations: The sudden torque surge during hydraulic breakers and narrow trench excavation causes uneven stress on the cylinder head bolts. Substandard flatness can lead to sealing leaks.

The 3TNV76 is a three-cylinder, water-cooled diesel engine. The cylinder head is the core component integrating the combustion chamber, valve train, and cooling system. The intake manifold, water jacket, injector holes, and valve guide holes are all integrally molded. Any deficiency in machining precision in any area will trigger a chain reaction of malfunctions, including high temperatures, power loss, and oil consumption. Traditional low-priced cylinder heads only replicate the external dimensions and are not optimized for the 3TNV76 model in terms of water channel routing and intake manifold curvature, thus providing only a temporary solution.

Keluo Construction Machinery's 3TNV76 cylinder head is made of high-toughness alloy cast iron in a single casting, improving its resistance to high-temperature thermal fatigue. This reduces the probability of water channel cracking and planar warping, especially important for mini excavators operating under frequent hot and cold cycles. The one-piece molded cooling water jacket has no seams, ensuring smooth coolant circulation and eliminating localized high-temperature points. The cylinder head's upper and lower mating surfaces undergo micron-level flatness grinding, with a full factory inspection for surface flatness to prevent cylinder head gasket leaks and oil-gas crosstalk. The intake and exhaust manifolds are precision-machined with streamlined shapes to improve intake and charging efficiency. After replacement, the engine idles more stably, fuel consumption decreases slightly, and there is no power reduction during crushing operations. Injector holes, rocker arm mounting holes, and bolt holes are machined in a single positioning process, achieving coaxiality standards. After assembly, valve timing is precise, and there are no abnormal engine noises or vibrations.

Hebei Keluo Construction Machinery Co., Ltd. possesses complete import and export qualifications and maintains ample stock year-round thanks to its large warehousing base, supporting both small-volume wholesale and full-container export, making it a premium choice for customers worldwide.