Inner & Outer Valve Spring 12300239 (Genuine DEUTZ/MWM Part)

1. Basic Information

• Part Number: 12300239
• Name: Valve Spring (Inner + Outer)
• Brand: DEUTZ / MWM
• Applicable Models:
  
  
  DEUTZ MWM TBG/TCG 2020/2032 series gas engines
  
  
  DEUTZ TCG 620 V12/V16/V20 series
  
  
  BF6M1013, BF4M2012 industrial, power generation and marine engines
• Applicable Valves: Universal for intake and exhaust valves (valve stem diameter: φ8 mm)

2. Material & Manufacturing Process

• Material: Chromium-vanadium alloy steel (SAE 6150), featuring high strength and excellent fatigue resistance.
• Heat Treatment: Quenched and tempered, hardness: HRC 48–54.
• Surface Treatment: Shot peening plus black oxide anti-rust treatment to extend fatigue service life.
• Operating Temperature: -40℃ ~ +450℃, suitable for high-temperature operating conditions of gas engines.

3. Key Dimensions (Original Standard)

Outer Spring

• Free Length: 68.8 mm
• Outer Diameter: φ30.5 mm
• Wire Diameter: φ4.2 mm
• Installed Height: 46.8 mm, Load: 360–400 N
• Maximum Compressed Length: 32.8 mm, Load: 602–672 N

Inner Spring

• Free Length: 72.0 mm
• Outer Diameter: φ20.5 mm
• Wire Diameter: φ3.0 mm
• Installed Height: 46.3 mm, Load: 154–170 N
• Maximum Compressed Length: 32.3 mm, Load: 285–315 N

4. Functions & Features

• Dual Spring Combination: Inner and outer springs are wound in opposite directions to prevent resonance and enhance rigidity, ideal for high-speed gas engines.
• Powerful Reset Performance: Ensures rapid opening and closing of valves and avoids delayed valve operation.
• Superior Fatigue Resistance: Chromium-vanadium steel combined with shot peening treatment enables great resistance to alternating loads and fracture prevention.
• Gas Engine Adaptability: Resists high-temperature creep and carbon deposition, with minor spring force attenuation during long-term operation.

5. Replacement & Compatibility

• Genuine Alternative Part No.: 12301790 (valve spring assembly for the same series)
• Recommended Aftermarket Brands: IZUMI, CTP, FEBI. Dimensions of inner and outer springs, wire diameter and material grade must be strictly matched.

6. Installation Instructions

1. Inspect springs for cracks, rust and deformation. Make sure the free length and spring force meet standard requirements.
2. Installation sequence: Fit the inner spring first, then the outer spring. Ensure the spring seats on both ends are flat.
3. Installation direction: Place the closed coil end towards the cylinder head to avoid motion interference.
4. Post-installation check: Verify the valves open and close smoothly without sticking or eccentric wear.
5. Complete replacement: Replace together with valves, valve seat inserts, valve guides and valve stem seals to guarantee reliable operation of the valve train system.