ISUZU Heat-resistant Steel Intake Valve with 45° Valve Seat Angle - OEM Standard Fit for 6BG1 6BD1 4BD1 Engines
Basic Properties
Place of Origin:
CHINA
Brand Name:
YIMI
Certification:
ISO/TS16949
Model Number:
6BG1 6BD1 4BD1 FSR NPR
Trading Properties
Minimum Order Quantity:
20 PCS
Price:
Negotiable
Payment Terms:
T/T,
Supply Ability:
10000 pcs/month
Specifications
| Valve Type: | Intake Valve | Quantity per Set: | 6 Pcs/set |
| Valve Head Diameter: | Engine Model Dependent | Valve Seat Angle: | 45° |
| Valve Stem Diameter: | Engine Model Dependent | Material: | Heat-resistant Steel |
| Valve Overall Length: | Engine Model Dependent | Unit Net Weight: | 0.14～0.15 Kg |
| High Light: | Heat-resistant steel Intake Valve,OEM Standard Fit Engine Valve,45° Valve Seat Angle VALVE; INL |
||
Product Description
ISUZU Intake Valve 1-12551139-0 1125511390 for 6BG1 6BD1 4BD1 Engine
OEM Standard Fit for FSR NPR Trucks & Hitachi Excavators
ISUZU Intake Valve 1-12551139-0 1125511390 Compatible with 6BG1 6BD1 4BD1 4BG1 Engines -- For FSR NPR NQR Trucks & Hitachi Excavators, OEM Standard Replacement
Product Overview
The ISUZU Engine Intake Valve with OEM numbers 1-12551139-0 / 1125511390 is a precision-engineered replacement designed for ISUZU 6BG1, 6BD1, 4BD1, 4BG1 series diesel engines. This valve is widely used in ISUZU FSR, NPR, NQR series trucks as well as Hitachi excavators and other construction machinery.
Working Principle
The intake valve is a vital part of the engine's valve train. During the intake stroke of a four-stroke engine, as the piston moves downward, the intake valve opens in advance and closes later (driven by the camshaft) to ensure more air/mixture enters the cylinder. The opening and closing timing must precisely match the piston position in the cylinder.
Failure Symptoms
⚠️ Inspect immediately if any of these occur:
| Symptom | Probable Cause |
|---|---|
| Noticeable power loss; poor acceleration; difficulty climbing hills | Intake valve poor sealing; reduced cylinder compression pressure |
| Rough idle; engine vibration; hard starting | Incorrect valve clearance or burnt valve; unstable intake air volume |
| Black smoke from exhaust (diesel) or increased fuel consumption | Insufficient intake air causing incomplete combustion; improper air-fuel ratio |
| Distinct "tapping" metallic noise from engine | Excessive valve clearance; or valve spring fatigue/fracture |
| Cylinder compression test reading below specification | Worn valve seat or bent valve stem; valve fails to seal completely |
Technical Specifications
Material Standard: Heat-resistant steel with operating temperature range of -40°C to 800°C
Dimensional Precision: Valve stem diameter machining precision to ±0.005 mm; valve seat angle 45° or 30°
Hardness Specification: Valve seat induction-hardened to HRC 50-55; valve stem tip hardness HRC 55-60
Unit Weight: 0.14-0.15 kg per piece
📌 Data Source Note: Material, hardness, and dimensional data are based on ISUZU 6BG1/6BD1 series engine factory workshop manual technical specifications and general industry standards (ISO, JIS). Test reports available upon request.
| Part Number: | 1-12551139-0 1125511390 |
| Product Name: | Intake Valve |
| Car Model: | FSR NPR |
| Engine Model: | 6BG1 6BD1 4BD1 |
| Condition: | 100% Brand New |
Vehicle & Engine Compatibility
Primary Engine Applications:
| Engine Model | Displacement | Primary Application |
|---|---|---|
| ISUZU 6BG1 | 6.5L | FSR/NPR trucks, Hitachi excavators |
| ISUZU 6BD1 | 5.8L | FSR/NPR trucks, construction equipment |
| ISUZU 4BD1 | 3.9L | NPR trucks, Hitachi excavators, JCB |
| ISUZU 4BG1 | 4.3L | Construction equipment, excavators |
Important Fitment Warnings:
- Intake vs. Exhaust Valve: This product is the Intake Valve with OEM 1-12551139-0. Exhaust valves use different part numbers.
- Valve Clearance Adjustment: After installation, valve clearance must be adjusted per ISUZU factory workshop manual specifications.
- Set Replacement Recommended: Replace intake and exhaust valves together with valve stem seals and valve springs.
- Valve Seat Inspection: Always inspect valve seat wear when replacing valves.
- Timing System Confirmation: Verify engine timing marks are aligned before installation.
Features & Benefits
High-Quality Heat-Resistant Steel Construction: Excellent high-temperature strength and creep resistance; maintains structural integrity at 800°C.
Precision Machining Process: Valve stem diameter precision to ±0.005 mm; valve seat angle accurate to 45°.
Valve Stem Tip Hardened: Tip hardness HRC 55-60 for superior wear resistance.
100% Factory Quality Inspection: 100% dimensional, hardness, and visual inspection on every piece.
Broad OEM Cross-Compatibility: Replaces OEM numbers 1125511650 / 1-12551165-0.
One Part Number, Multiple Engine Models: Same valve fits 6BG1, 6BD1, 4BD1, 4BG1, 4BC2 engines.
Quality Control
| QC Item | Inspection Method | Acceptance Criterion |
|---|---|---|
| Valve stem diameter | Laser micrometer / Micrometer | ±0.005 mm |
| Valve seat angle | Special angle gauge / Profilometer | 45° ± 0.5° |
| Valve seat hardness | Rockwell hardness tester (HRC) | HRC 50-55 |
| Valve stem tip hardness | Rockwell hardness tester (HRC) | HRC 55-60 |
Installation & Maintenance
⚠️ IMPORTANT SAFETY NOTICE: Engine valves and cylinder head areas reach extremely high temperatures after operation. Allow the engine to cool completely before proceeding. Professional installation with specialized tools is strongly recommended.
Maintenance Schedule:
| Item | Interval | Notes |
|---|---|---|
| Valve clearance check/adjustment | Every 20,000-30,000 km | Check immediately if noise detected |
| Cylinder compression test | Every 50,000 km | Check valve sealing integrity |
| Valve assembly replacement | Engine overhaul (300,000-500,000 km) | Depends on operating conditions |
Packaging & Supply
| Packaging | Inner: Anti-rust bag / oil paper Outer: Standard export carton |
| Quantity per package | 6 pcs/set (for 6-cylinder engines) |
| Unit net weight | Approx. 0.14-0.15 kg |
| Target Customers | Truck parts wholesalers, repair shops, construction equipment parts suppliers |
Related Products
Engine Block 5873102680 5-87310268-0 For ISUZU 100P 4JB1 Diesel Engine Parts
Engine Block 5873102680 5-87310268-0 For ISUZU 100P 4JB1 Diesel Engine Parts Part Number: 5873102680 5-87310268-0 Product Name: Engine Block Car Model: ISUZU 100P Engine Model: ISUZU 4JB1 Condition: 100% Brand New Size: Standard Weight: Standard Origin: China Mainland Main Market: Middle East ,Asia...
Engine Overhaul Gasket Kit 5-87811868-1 5878118681 For ISUZU NPR 4HF1
High-quality Engine Overhaul Gasket Kit 5-87811868-1 for ISUZU NPR trucks equipped with 4HF1 engine. Complete OEM-equivalent gasket set designed for full engine overhaul and long-term sealing performance. Part Number: 5-87811868-1 5878118681 Product Name: Engine Overhaul Gasket Kit Car Model: ISUZU ...
Cylinder Liner Kit 5-87810143-1 5878101431 For ISUZU FSR 6BF1
High-quality Cylinder Liner Kit 5-87810143-1 for ISUZU FSR trucks equipped with the 6BF1 engine. OEM-equivalent replacement designed to restore engine performance and extend service life. Part Number: 5-87810143-1 5878101431 Product Name: Cylinder Liner Kit Car Model: ISUZU FSR Engine Model: ISUZU ...
Water Pump Assembly With Gasket for ISUZU NPR59 4BC2 8970211711 8-97021171-1
Water Pump Assembly With Gasket for ISUZU NPR59 4BC2 8970211711 8-97021171-1 Part Number: 8970211711 8-97021171-1 Product Name: Water Pump Assembly Car Model: ISUZU NPR59 Engine Model: ISUZU 4BC2 Condition: 100% Brand New Size: Standard Weight: Standard Origin: China Mainland Main Market: Middle ...
