FAW J6P Cylinder Head: The Ultimate 4-Core Guide to Its Serviceable Parts

Welcome to this definitive technical deconstruction of the FAW J6P Cylinder Head, the core serviceable casting for the engine powering the FAW Jiefang CA3250P66K2L1T1E 6×4 diesel dump truck.

This is not the *complete* assembly, but the “bare head” itself (P/N 1003011A59D / 1003011-59D)—the single most complex casting in the powertrain.

The “logic” of the FAW J6P Cylinder Head is to be the “control room” of combustion. It must perform three critical tasks: withstand immense heat and pressure, manage all engine “breathing” (airflow), and serve as a complex heat exchanger.

The “design logic” of this specific FAW J6P Cylinder Head is centered on durability and, most importantly, “serviceability.” This component group is what an engine machine shop would use to rebuild a head. It includes the replaceable “wear” items that are press-fit into the main casting, such as the valve guides and valve seats. A crack or warp in the main FAW J6P Cylinder Head casting is one of the most severe engine failures, as it allows coolant, oil, and combustion gases to mix, leading to catastrophic failure. Understanding its serviceable components is therefore essential for any long-term fleet maintenance.

This expert guide is an essential resource for engine rebuilders, machine shop technicians, and parts managers. We will deconstruct this entire 10-component type group into its four primary “logic” systems: the “Main Casting & Brake” Logic (the bare head itself), the “Valvetrain Interface” Logic (the replaceable guides and seats), the critical “Injector Sealing” Logic (copper sleeves and O-rings), and the “Foundry Sealing” Logic (the various plugs that make the FAW J6P Cylinder Head casting fluid-tight).

Core 1: The “Main Casting & Brake” Logic (Component 1)

This component is the structural foundation for this entire group. All other parts are installed *into* this one.

1. Component: ‘Cylinder head’ (1003011A59D / 1003011-59D)
This is the main FAW J6P Cylinder Head casting. The parts list shows two distinct part numbers, and the “logic” is explicitly stated: one (1003011A59D) is for trucks “with engine brake,” and the other (1003011-59D) is for trucks “without engine brake.” This is a critical distinction. The “Engine Brake Logic” of the ‘A59D’ part means the casting has complex, additional oil galleries drilled deep into it. These passages are designed to route high-pressure engine oil to the engine brake (or “Jake Brake”) system, which is housed in the rocker assembly above. The “non-brake” FAW J6P Cylinder Head lacks these passages and is a simpler, and therefore different, casting.

Both versions share the same “foundry logic,” being cast from a high-strength, temperature-stable iron alloy. Their “thermal logic” is the intricate “water jacket”—a complex, web-like internal passage that allows coolant to circulate aggressively around the two hottest areas: the exhaust valve seats and the fuel injector bores. This prevents the FAW J6P Cylinder Head from warping or cracking under extreme load. The “airflow logic” of this FAW J6P Cylinder Head is in its precision-cast intake and exhaust ports, which are shaped to optimize air “swirl” for a clean, powerful combustion.

Core 2: The “Valvetrain Interface” Logic (Components 8, 9, 10)

This group represents the core “serviceability logic” of the FAW J6P Cylinder Head. These are the “wear” surfaces for the valvetrain, and they are designed to be replaceable.

1. Component: ‘Valve guide’ (1003014-29D)
The list calls for 24 guides (Comp 8), one for each of the 24 valves (12 intake, 12 exhaust). The “logic” of a ‘Valve guide’ is to be a replaceable, low-friction sleeve. The FAW J6P Cylinder Head casting is iron, but running a hardened valve stem directly in the iron would cause rapid wear. Instead, these guides (often made of a bronze alloy or a different iron composite) are “press-fit” into the head. Their “precision logic” is to hold the valve in perfect alignment, allowing it to seal correctly against the seat. When these wear out, they can be “pressed” out and replaced, restoring the FAW J6P Cylinder Head to “like-new” condition.

2. Components: ‘Intake valve seat’ (1003012-36D) & ‘Exhaust valve seat’ (1003013-36D)
This is the “Combustion Sealing Logic.” The valves must seal against a perfectly round, incredibly hard surface. The cast iron of the FAW J6P Cylinder Head is too soft for this. The “logic” here is to press-fit two different types of ‘Valve seats’ (Comp 9 & 10) into the head. The ‘Exhaust valve seat’ (Comp 9) is made of a very hard, high-temperature steel alloy (like Stellite) to withstand superheated exhaust gases. The ‘Intake valve seat’ (Comp 10) is also hardened steel, but with different properties as it is cooled by the intake air. Their “service logic” is that they are the “sacrificial” part; they can be re-ground (a “valve job”) multiple times, and if they wear too much, they can be machined out and replaced, which saves the entire FAW J6P Cylinder Head casting from being scrapped.

Core 3: The “Injector Sealing” Logic (Components 3 & 4)

This group’s “logic” is to create a perfect, “dual-seal” for the high-pressure fuel injectors. This is a critical task in a modern diesel, sealing both combustion *in* and fluids *out*.

1. Component: ‘Injector copper sleeve’ (1003016-29D)
The list calls for 6 sleeves (Comp 4), one for each injector. This component’s “logic” is “combustion sealing” and “heat transfer.” This sleeve is pressed into the bottom of the injector bore in the FAW J6P Cylinder Head. The “copper logic” is that copper is a soft, malleable metal. It creates a perfect “crush” seal against the injector tip, preventing the 2500+ PSI of combustion gas from escaping. It also acts as a vital “heat sink,” pulling heat *away* from the delicate injector tip and transferring it into the coolant in the FAW J6P Cylinder Head‘s water jacket. This dual-seal system is a hallmark of a robust, modern diesel engine design.

2. Component: ‘O-ring’ (1003018-29D)
The list calls for 6 O-rings (Comp 3). This is the “fluid sealing logic.” These O-rings sit in a groove higher up on the injector or injector sleeve. Their “logic” is to prevent fluids (fuel from the return galley or oil from the valvetrain) from leaking *out* of the engine, and to prevent coolant from leaking *into* the injector bore. A failure of the copper sleeve (Comp 4) leads to combustion in the coolant; a failure of the O-ring (Comp 3) leads to fuel in the oil or an external leak. Both are critical seals for the FAW J6P Cylinder Head.

Core 4: The “Foundry Sealing” Logic (Components 2, 5, 6, 7)

This final group’s “logic” is simple: to plug the holes left by the manufacturing process. A complex casting like a FAW J6P Cylinder Head cannot be made without numerous access holes.

Components: ‘Bowl plug’ (Q72240, Q72232, Q72222, Q72226)
These components are commonly known as “freeze plugs” or “core plugs.” Their “logic” is to seal the large, circular holes in the FAW J6P Cylinder Head casting. These holes are an essential part of the “sand casting” process, as they are used to remove the internal sand “core” that forms the complex shape of the water jacket. After casting, these plugs are hammered or pressed in to create a permanent, watertight seal for the cooling system.

The parts list shows a high quantity (1 + 1 + 6 + 16 = 24 total plugs) of various sizes, which demonstrates the extreme complexity of the internal coolant passages. Note that, just like the head casting itself, there is a specific ‘Bowl plug’ (Comp 5, Q72232) designated for the “engine brake” version. This “brake logic” implies it is used to seal a specific access hole that was drilled for the engine brake’s oil gallery, a hole that does not exist on the non-brake version of the FAW J6P Cylinder Head.

FAW J6P Cylinder Head Parts List & Specifications

The following table provides the complete, detailed breakdown of all 10 serviceable component types identified in this FAW J6P Cylinder Head group for the FAW Jiefang CA3250P66K2L1T1E 6×4 dump truck.

Core Specifications

The specifications for the bare FAW J6P Cylinder Head are defined by its function as the serviceable core for airflow and combustion.