8972221171 Original Excavator Gasket for ISUZU Engine 4BG1

Part number 8972221171 is the original gasket (usually cylinder gasket or valve cover gasket) provided by Hitachi Construction Machinery for hydraulic excavators equipped with ISUZU 4BG1 series diesel engines. This gasket is mainly suitable for small excavators of 6-12 tons such as Hitachi ZX60, ZX70, ZX120, as well as domestic models such as Sany SY155C-9 (with a total weight of 14.1 tons) that use 4BG1 engines. Its universal models can cover engines of the 4BG1T, 4BD1, 4JG1 series, and have interchangeability in some models of brands such as Hitachi, Kobe Steel, and Sumitomo. As an original sealing component, it should be accurately matched with the flatness and bolt hole position of the cylinder block/cylinder head. It is strictly prohibited to use non-standard auxiliary components to prevent seal failure from causing oil leakage, air leakage or cylinder flushing.

This product is an original multi-layer composite steel pad (or oil resistant rubber pad), with a typical structure of two thin steel plates sandwiching graphite or rubber layers. Technical parameters: Thickness of approximately 1.2-1.5mm, temperature resistance range of -40 ℃ to+300 ℃, compressive strength ≥ 15MPa, compression rebound rate ≥ 80%. The surface of the gasket is treated with anti stick coating, and the edge has positioning protrusions to ensure accurate alignment during installation. Its sealing performance meets standards such as ISO 15552 and GB/T 12617, effectively sealing the cylinder combustion chamber, oil passage, and cooling water passage, and resisting corrosion from diesel, oil, and coolant. For turbocharged models (4BG1T), the gasket also strengthens the heat-resistant layer on the exhaust side to cope with higher heat loads.

Disassembly inspection: During major repairs or gasket replacement, the joint surface between the cylinder block and cylinder head must be thoroughly cleaned (removing old gasket residue and carbon scale), and the flatness must be checked with a ruler (allowable deviation ≤ 0.05mm). Installation points: 1 Confirm the front and back of the gasket (usually marked with "TOP" or "FRONT" facing up and forward); 2. Apply a small amount of sealant evenly (only for non-metallic gaskets, silicone sealant is recommended); 3. Tighten the cylinder head bolts step by step according to the original factory order (torque usually 80-100N · m, cross tighten 3-4 times). Run in and recheck: After installation, the cylinder head bolts should be tightened again while the car is in a hot state for the first 50 hours of operation; Check for signs of leakage and erosion every 500 working hours.