Intake Valve 1-12551139-0 For Isuzu FSR NPR - High-alloy Heat-resistant Steel OEM Standard Direct Replacement Engine Valve

The Intake Valve (OEM Numbers: 1-12551139-0 / 1125511390) is a premium-quality, direct replacement engine valvetrain component designed for Isuzu FSR and NPR series medium-duty trucks equipped with various diesel engines. This valve opens at the correct time to allow fresh air into the combustion chamber, ensuring efficient engine breathing and performance.

• OE Quality: Manufactured to Isuzu dimensional and material specifications for perfect fit and long service life
• Heat-Resistant Alloy: Silicon-chromium steel resists oxidation and thermal fatigue
• Hardened Tip: Reduces wear from rocker arm contact
• Precision-Ground Stem: Smooth surface reduces guide wear and ensures proper oil control
• Hardened Valve Face: Provides durable sealing against the valve seat, preventing gas leakage
• Restores Engine Performance: Eliminates compression loss, rough idle, and hard starting
• Direct Replacement: Matches OE length, head diameter, and stem size - no modification required
• Cost-Effective: Affordable alternative to genuine OEM without compromising quality

Isuzu Truck Models:

• ISUZU FSR (medium-duty truck)
• ISUZU NPR (medium-duty truck)
• Other Isuzu trucks using 4BD1, 4BG1, 6BG1 engines

Engine Specifications:

Installation steps overview for OHV engine:

1. Remove cylinder head - as per engine service manual
2. Clean cylinder head - remove carbon deposits from valve ports and combustion chamber
3. Remove old intake valves - use valve spring compressor to release keepers, remove spring, and pull out valve
4. Inspect valve guides - measure stem-to-guide clearance. Replace guides if worn
5. Inspect valve seats - grind or cut seats to proper angle and width
6. Lubricate new valve stem - with engine oil or assembly lube
7. Insert new intake valve - into the guide from the combustion chamber side
8. Install valve spring, retainer, and keepers - compress spring and secure keepers
9. Lap the valve (if necessary) - apply lapping compound and rotate valve against seat to ensure sealing
10. Check installed height - measure valve spring height; adjust with shims if needed
11. Reinstall cylinder head - with new head gasket. Torque head bolts to specification
12. Adjust valve clearance - set intake valve lash to OE specification (typically 0.25-0.35mm cold for Isuzu engines)
13. Start engine - check for smooth operation and correct valve train noise

• Material Verification: Ensures metal brackets meet strength and corrosion-resistance standards
• Dimensional Accuracy: Verified against OE specifications for precise fit
• Visual Inspection: 100% checked for cracks, defects, or manufacturing imperfections
• Packaged Safely: Protected to prevent damage during transit

• Neutral export packing or customized packaging available
• Carton or wooden case for safe transportation
• Fast delivery for stock items
• Shipping by Express Air or Sea