CAT 326-4740 / 32E61-00022 Fuel Injector – Optimised Low-Flow Linearity with Advanced Solenoid Response for C13/C15 Common-Rail Systems
1. Product:326-474032/E61-00022
2. Compatible Equipment: Diesel Fuel Injection Systems
3. Manufacturer: Aftermarket OEM Replacement
4. Condition: Brand New, Fully Tested
5. Origin: ABOSEDE Diesel
6. Shipping period: 3-5 business days
7. Payment terms: T/T, Western Union, PayPal
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Product Introduction
In the common-rail industry, injector performance is often judged by its peak flow capability and its response at full load. Yet the vast majority of operating hours for a heavy-duty diesel engine are spent at partial load and idle, where the injector commands short pulse widths (0.3–0.7 ms) and delivers small fuel quantities. In this low-flow region, the injector's linearity-the relationship between the commanded pulse width and the delivered fuel-becomes the defining factor in combustion stability. A non-linear injector delivers a fuel quantity that deviates from the ECM's calculation, causing cylinder-to-cylinder imbalance and a rough idle. The CAT 326-4740 / 32E61-00022 is engineered with a low-flow optimisation package that ensures a linear fuel delivery down to 0.3 ms, providing a smoother idle, more consistent low-load combustion, and a reduced burden on the ECM's adaptive learning.
Low-Flow Optimisation – The Science of Short-Pulse Accuracy
The 326-4740 achieves its low-flow linearity through a combination of design refinements. The armature mass is reduced by 4% compared to the standard C13/C15 injector, lowering the inertia that causes the needle to lag at short pulses. The bleed orifice is precision-ground to 0.188 mm with a tolerance of ±0.001 mm, ensuring a consistent pressure drop even at the beginning of the injection event. The spring preload is set to 28.0 N-slightly lower than the 29.0 N of the high-flow variants-allowing the needle to lift more readily at low command currents. These refinements result in a linearity deviation of less than 1.8% from 0.3 ms to 1.5 ms, compared to the 3.5% typical of standard injectors.
Solenoid Response – The Electrical Foundation of Low-Flow Precision
The solenoid of the 326-4740 is designed with a controlled inductance of 0.53 mH and a current rise time of 0.22 ms to reach the 1.68 A opening threshold. This rise time is calibrated to match the control chamber's bleed rate, ensuring that the needle begins to lift at the moment the control chamber pressure has dropped to the required level. The solenoid also features a magnetic circuit with low remanence (residual magnetism) of 0.02 T-a 50% reduction compared to standard solenoids-which eliminates the cycle-to-cycle variation that can occur when residual magnetism affects the armature's movement at short pulses.
Electrical data:
Coil resistance (20°C): 0.55–0.63 Ω
Inductance (1 kHz, 1.5 A): 0.52–0.54 mH
Opening current threshold: 1.68 A
Holding current: 0.82–0.90 A (PWM at 1.2 kHz)
Current rise time to 1.68 A: 0.22 ms
Residual magnetism: ≤ 0.02 T