The Caterpillar 7N-1903 Inner Valve Spring is a high-fatigue, precision-engineered engine compression hardware component. It is engineered to maintain extreme valve train stability, ensure positive intake and exhaust valve seating, and prevent harmonic valve float across high-displacement internal combustion engines subject to relentless thermal cycles and mechanical vibrations.
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Core Dimensions & Fastener Specs
Free Length: 51.54 mm (2.029 in)
Maximum Solid Length: 28.68 mm (1.129 in)
Spring Type: Helical Compression Inner Valve Spring
Installation Fit: Concentric placement inside the outer valve spring
Application Target: Cylinder head valve train assembly (Intake & Exhaust positions) -
Material & Manufacturing Specs
Material Grade: Premium high-fatigue shot-peened carbon/alloy valve spring steel.
Coating & Finish: Anti-corrosion industrial oil film coating to resist harsh engine fluids, storage humidity, and acid formation.
Manufacturing Standards: Manufactured to precise OEM geometric tolerances under ISO 9001 quality controlled facilities to guarantee consistent spring rate and elasticity. -
Equipment & System Compatibility
This high-durability internal valve spring is standard heavy-duty hardware deployed across a vast selection of large-scale Caterpillar heavy machinery, marine propulsion systems, and high-horsepower power generation platforms:
Engine Platforms: Integrated into core cylinder head groupings for CAT 3500-series heavy diesel and gas configurations, explicitly supporting 3508, 3512, 3516, G3508, G3512, G3516, G3520B, G3612, and G3616 power plants.
Heavy Earthmovers & Track Dozers: Widely used within the powertrain grids of ultra-class mine tractors and heavy infrastructure crawler fleets equipped with 3500-series engine groups.
Ultra-Class Mining Trucks: Deployed in the propulsion systems of mining haulers including primary heavy-duty variants of the CAT 785, 789, and 793 engine bays. - Part Cross-References
Alternative Part Names: Inner Valve Compression Spring, Engine Valve Spring, Lò xo xupap trong 7N-1903.
Alternative Part Numbers: 7N1903, 7N-1903.
