CAT 320-0670 Fuel Injector – Consistent Solenoid Response with Reduced Cyclic Variation for C7/C9/C9.3 Common-Rail Engines
1. Product:320-0670
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
- Fast Delievery
- Quality Assurance
- 24/7 Customer Service
Product Introduction
In the world of common-rail injection, the ECM commands a specific pulse width, and the injector is expected to deliver a corresponding fuel quantity. Yet even with a perfectly stable rail pressure and a constant pulse width, the actual fuel delivery can vary from cycle to cycle-a phenomenon known as cyclic variation. This variation is primarily caused by inconsistencies in the solenoid's magnetic behaviour: minor changes in the armature's movement, variations in the current rise time, and the residual magnetism left over from the previous pulse. The CAT 320-0670 addresses this through a solenoid design with reduced residual magnetism and a stabilised armature guide, ensuring that each injection event starts from the same magnetic baseline. The result is a cyclic variation of less than 1.5%, compared to the 2.5–3.5% typical of standard injectors-a benefit that translates into a smoother idle, more consistent combustion, and lower emissions.
Residual Magnetism – The Hidden Source of Cycle-to-Cycle Variation
When the solenoid is de-energised, the magnetic field does not disappear instantly-a small amount of residual magnetism remains in the stator, which affects the next injection event. If the residual magnetism is not consistent, the armature's movement varies from cycle to cycle, changing the opening delay and the fuel quantity. The 320-0670 uses a high-purity nickel-iron alloy stator that reduces the residual magnetism to 0.02 T (tesla)-a 50% reduction compared to the silicon-iron stators used in earlier injectors. This lower residual magnetism ensures that the armature's lift is consistent from cycle to cycle, regardless of the history of the previous injections.
Armature Guide – The Mechanical Foundation of Consistency
The armature's movement is guided by a precision-ground sleeve with a clearance of 0.008–0.012 mm-tighter than the 0.010–0.015 mm typical of many injectors. This tighter guide clearance reduces the lateral movement of the armature, ensuring that it travels coaxially and consistently reaches the same stop position each time. The guide is also hard-chrome plated to a thickness of 0.015 mm, resisting the wear that can cause the clearance to increase over time. The result is a stable armature movement that maintains the cyclic variation within the 1.5% specification throughout the injector's service life.