Intake Valve 1-12551139-0 For Isuzu FSR NPR 1125511390 Engine Isuzu Spare Parts
Product Overview
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.
Technical Specifications
Part Number
1-12551139-0, 1125511390
Product Name
Intake Valve / Engine Intake Valve
Car Model
ISUZU FSR, ISUZU NPR
Engine Model
ISUZU 4BD1, 4BG1, 6BG1, etc.
Quality Standard
OEM equivalent / ISO quality control
Features & Advantages
- 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
Vehicle & Engine Compatibility
Isuzu Truck Models:
- ISUZU FSR (medium-duty truck)
- ISUZU NPR (medium-duty truck)
- Other Isuzu trucks using 4BD1, 4BG1, 6BG1 engines
Engine Specifications:
| Engine |
Displacement |
Cylinders |
Notes |
| 4BD1 |
3.9L (3856cc) |
Inline 4 |
Naturally aspirated |
| 4BG1 |
3.9L (3856cc) |
Inline 4 |
Turbo variant |
| 6BG1 |
6.5L (6549cc) |
Inline 6 |
N/A or turbo |
Please verify fitment for your specific engine model
Installation Notes
Installation steps overview for OHV engine:
- Remove cylinder head - as per engine service manual
- Clean cylinder head - remove carbon deposits from valve ports and combustion chamber
- Remove old intake valves - use valve spring compressor to release keepers, remove spring, and pull out valve
- Inspect valve guides - measure stem-to-guide clearance. Replace guides if worn
- Inspect valve seats - grind or cut seats to proper angle and width
- Lubricate new valve stem - with engine oil or assembly lube
- Insert new intake valve - into the guide from the combustion chamber side
- Install valve spring, retainer, and keepers - compress spring and secure keepers
- Lap the valve (if necessary) - apply lapping compound and rotate valve against seat to ensure sealing
- Check installed height - measure valve spring height; adjust with shims if needed
- Reinstall cylinder head - with new head gasket. Torque head bolts to specification
- Adjust valve clearance - set intake valve lash to OE specification (typically 0.25-0.35mm cold for Isuzu engines)
- Start engine - check for smooth operation and correct valve train noise
Quality Control
- 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
Packaging and Delivery
- 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