FAW J6P Piston & Connecting Rod: Deconstructing 11 Critical Parts for Flawless Power

Welcome to this expert deconstruction of the FAW J6P Piston and Connecting Rod assembly. This is the heart of the engine for the FAW Jiefang CA3250P66K2L1T1E 6×4 dump truck.

This is not a simple set of parts; it is a “Logic Assembly” engineered to perform the single most critical task in the engine: converting the violent, high-pressure explosion of diesel combustion into smooth, rotational power.

The “logic” of this assembly is a perfect partnership. The FAW J6P Piston (Comp 10) is the “shield,” enduring the heat and force. The Connecting Rod (Comp 5) is the “arm,” transferring that force to the crankshaft.

The “Combustion Logic” of this FAW J6P Piston (P/N 1004011-630-0000F) is its most advanced feature. It is not a flat-top piston; it features a complex “bowl” design. This bowl is a precision-engineered combustion chamber, designed to create a “swirl” and “tumble” in the compressed air. When fuel is injected, this swirl logic ensures a perfect, instantaneous air-fuel mixture, leading to a more complete, more powerful, and cleaner combustion. This design is what gives the FAW J6P Piston its reputation for efficiency and power.

This technical guide is an essential resource for engine rebuilders, machine shop technicians, and fleet parts managers. We will deconstruct the entire 11-component group into its four primary “logic” systems: the “Sealing Logic” (the piston rings), the “Pivot & Transfer Logic” (the rod, pin, and retainers), the critical “Hydrodynamic Bearing Logic” (the rod bearings), and the “Critical Fastener Logic” (the high-tensile rod bolts). This is the complete guide to the FAW J6P Piston and rod assembly.

Core 1: The “Combustion & Sealing” Logic (Components 1, 2, 3, 10)

This group forms the “face” of combustion. Its logic is to harness the explosion while creating a near-perfect gas and oil seal.

1. Component: ‘Piston’ (1004011-630-0000F)
This is the core component (Comp 10). The FAW J6P Piston is made from a high-strength, low-expansion aluminum alloy. Its “Thermal Logic” is an internal, cast-in “cooling gallery.” Engine oil is sprayed up from the block, fills this gallery, and carries heat away from the piston crown, preventing it from melting under the load of a heavy-duty diesel.

2. The “Ring Pack” Logic (Components 1, 2, 3)
The “Sealing Logic” of the FAW J6P Piston is handled by its three-part “ring pack.”

• ‘First compression ring’ (1004012-36D): This is the “firewall.” Its logic is to contain the 2000+ PSI of combustion pressure. It is often “Keystone” (wedge) shaped to prevent it from sticking in the groove.
• ‘Second compression ring’ (1004013-36D): This is the “secondary seal” or “scraper.” Its logic is to catch any pressure that leaks past the first ring and to begin scraping excess oil *down* the cylinder wall.
• ‘Oil ring assy’ (1004030-36D): This is the “Oil Control Logic.” This is a complex, multi-piece ring (Comp 3). Its logic is to scrape the vast majority of oil off the cylinder wall on the downstroke, leaving only a microscopic film for lubrication. Failure of this ring is the primary cause of blue smoke (oil burning) and high oil consumption. This ring pack is critical to the function of the FAW J6P Piston.

Core 2: The “Pivot & Transfer” Logic (Components 4, 5, 9, 11)

This group forms the “arm” that connects the FAW J6P Piston to the crankshaft. Its logic is about transferring immense force while allowing for precise movement.

1. Component: ‘Fracture-split connecting rod body’ (1004021-36D)
This (Comp 5) is a masterpiece of modern engineering. Its “Fracture-Split Logic” is critical. To install the rod on the crankshaft, the “big end” must be a two-part cap. Instead of “sawing” the cap, manufacturers *snap* it apart with a high-powered laser or hydraulic press. This “fracture” creates a perfectly irregular, 100% unique, matched surface. This “logic” means the cap can *never* shift side-to-side, which is a common failure point in older, “machined-cap” rod designs.

2. The “Pivot” Logic (Components 4, 9, 11)
This sub-assembly connects the FAW J6P Piston to the rod (Comp 5).

• ‘Piston pin’ (1004018-630-0000Z): This (Comp 11) is the hardened steel “wrist pin” that forms the pivot.
• ‘Connecting rod small end bush’ (1004024-630-0000): This (Comp 4) is the “Sacrificial Pivot Logic.” This bronze sleeve is pressed into the “small end” of the connecting rod. The piston pin floats inside it. This bush is the “wear item,” saving the expensive connecting rod from damage.
• ‘Retaining ring 45’ (GB893.1-1986 45): This is the “Containment Logic.” The list calls for 12 (Comp 9), or 2 per FAW J6P Piston. These “circlips” snap into grooves inside the piston itself, preventing the ‘Piston pin’ from sliding sideways and gouging the cylinder wall.

Core 3: The “Hydrodynamic Bearing” Logic (Components 6, 7)

This group’s “logic” is to allow the connecting rod to spin at thousands of RPM on the crankshaft *without ever touching it*. This is the “Hydrodynamic Logic” central to all modern engines.

Components: ‘Connecting rod upper bearing’ (1004026-36D) & ‘Lower bearing’ (1004028-36D)
The connecting rod “big end” floats on a microscopic film of high-pressure oil. These ‘bearings’ (Comp 6 & 7) are the precision, multi-layer, soft-metal shells that are engineered to hold this oil film. Their “Sacrificial Logic” means they are the “wear item.” If any debris (carbon, metal) gets in the oil, it will embed in the soft bearing, saving the hardened, expensive crankshaft from scratches.

The “Load Logic” is also key. The ‘Upper bearing’ (Comp 6), which sits in the main rod body, takes the full, massive, downward force of the FAW J6P Piston‘s combustion stroke. The ‘Lower bearing’ (Comp 7), in the cap, takes the high-RPM “whipping” force on the other strokes. They are engineered differently to handle these specific, opposing loads.

Core 4: The “Critical Fastener” Logic (Component 8)

This final component is arguably the single most stressed fastener in the entire engine. Its “logic” is to provide a massive, unyielding clamping force.

1. Component: ‘Connecting rod bolt’ (1004023A29D)
The list calls for 12 bolts (Comp 8), two for each of the six connecting rods. These are the “Clamping Force Logic.” They must handle two forces: the “push” from the combustion stroke (which tries to crush the bearings) and the “pull” from the high-RPM exhaust stroke (which tries to rip the cap off).

These are “Torque-to-Yield” (TTY) bolts. Their “logic” is that they are designed to be torqued to a specific point where they *permanently stretch*. This stretching action turns the bolt into a high-tension spring, providing a perfectly consistent clamping force that the “fracture-split” cap (Comp 5) requires to stay locked in place. This is why they are *single-use*. Once stretched, they are compromised and MUST be replaced any time the FAW J6P Piston or rod assembly is serviced.

FAW J6P Piston & Connecting Rod Parts List & Specifications

The following table provides the complete, detailed breakdown of all 11 component types identified in this FAW J6P Piston and Connecting Rod assembly for the FAW Jiefang CA3250P66K2L1T1E 6×4 dump truck.

Core Specifications

The specifications for the FAW J6P Piston and Rod Assembly are defined by its function as the core of the engine’s rotating assembly.