الدليل الشامل: مجموعة رأس الأسطوانة FAW للجرار CA4251P66K24T1A3E5

This comprehensive technical guide provides an exhaustive analysis of the FAW مجموعة رأس الاسطوانة (الجزء لا. 1003011-81د), a core component of the engine for the FAW Jiefang CA4251P66K24T1A3E5 6×4 جرار نصف مقطورة ديزل.

ال FAW مجموعة رأس الاسطوانة is arguably the most complex and critical static component in the powertrain. It serves as the “lungs” من المحرك, managing all airflow, حقن الوقود, and combustion, while also routing high-pressure oil for lubrication and coolant for thermal management.

This exploded-view analysis is designed for professional engine rebuilders, محلات الآلات, and service technicians. We deconstruct the entire FAW مجموعة رأس الاسطوانة into its smallest serviceable units, from the main casting and valvetrain components to the individual seals, المقابس, and dowel pins that are essential for a successful engine overhaul.

المكون الأساسي: The Cylinder Head Casting (1003011-81د)

أساس الكل FAW مجموعة رأس الاسطوانة هو الصب الرئيسي (الجزء لا. 1003011-81د). This single component is a masterpiece of foundry work, typically made from a high-strength, high-temperature cast iron or a specialized aluminum alloy. It is responsible for sealing the top of the engine’s cylinders, forming the upper half of the combustion chamber.

Its complex internal structure is a marvel. It contains intricate, cast-in-place “سترات المياه” that allow engine coolant to circulate mere millimeters away from the combustion chambers and exhaust ports, absorbing and carrying away the immense heat of combustion. Failure to control this heat would lead to component warping, detonation, and catastrophic engine failure.

معًا, it features a separate network of drilled passages that carry high-pressure oil from the engine block up to the valvetrain, lubricating the camshafts, الأسلحة الروك, and valve stems. The precision of this casting is paramount. ال “ظهر السفينة” surface—the bottom face that meets the engine block—must be perfectly flat to ensure a complete seal with the head gasket, containing the millions of PSI generated during the power stroke.

Valvetrain Infrastructure: Seats and Guides

هذا FAW مجموعة رأس الاسطوانة is a four-valve-per-cylinder design, which is a hallmark of modern, efficient diesel engines. This is evidenced by the parts list quantities: for a six-cylinder engine, نرى 12 ‘Intake Valve Seats’ (1003012-81د) و 12 ‘Exhaust Valve Seats’ (1003013-81د). هذا 2:2 split per cylinder (2 المدخول, 2 العادم) allows for superior airflow, أو “التنفس,” resulting in more complete combustion and higher power output.

The valve seats are not part of the casting itself. They are separate rings made of an extremely hard, specialized steel alloy. ال “أكثر ليونة” head casting is machined, and these hardened seats are chilled (often with liquid nitrogen) and pressed into place, where they expand to form an interference fit. They serve two functions: to provide a durable, heat-resistant surface for the valve to seal against, and to transfer the valve’s heat into the water-cooled head. Exhaust valve seats, بخاصة, are made from exotic alloys to withstand the superheated exhaust gases.

لدعم 24 الصمامات (12 المدخول, 12 العادم), the parts list specifies 24 ‘Valve Guides’ (1003014-81د). These are bronze or iron sleeves that are also pressed into the head. The valve stem passes through this guide, which holds the valve in perfect alignment as it opens and closes thousands of times per minute. The guide also serves as a critical heat-transfer path, drawing heat from the valve stem and conducting it into the head casting.

These components—seats and guides—are the primary “وحدات صالحة للخدمة” for an engine machine shop. متأخر , بعد فوات الوقت, the seats wear from the constant pounding of the valves, and the guides wear, leading to oil consumption and poor valve sealing. أ “valve job” on a FAW مجموعة رأس الاسطوانة involves machining or replacing these specific parts to restore the head to a like-new condition.

Fuel Injector Integration Components

In a modern direct-injection diesel, the fuel injector tip sits directly in the combustion chamber. في FAW مجموعة رأس الاسطوانة, this is accomplished by passing the injector through the water jacket. To make this possible, six ‘Injector Copper Sleeves’ (1003016-81د) تستخدم, واحد لكل اسطوانة.

This copper sleeve is a thin-walled tube that is pressed and sealed into the head, creating a dry “tunnel” through the coolant. It serves three critical functions: it seals the coolant *out*, it seals the high-pressure combustion gases *in* (في الأسفل), and its copper construction provides excellent heat transfer, using the engine coolant to cool the high-performance injector.

The parts list also shows six ‘O-rings’ (1003018-53د). These are most likely the seals used at the top of the injector sleeve or on the injector itself, preventing oil from the valvetrain (above) or coolant (from a potential sleeve leak) from seeping down into the fuel system.

Camshaft Bearing Caps and Alignment

هذا FAW مجموعة رأس الاسطوانة is an overhead cam (اوهك) تصميم, meaning the camshaft(ق) are housed within the head. The head casting forms the lower half of the camshaft bearing. The ‘Camshaft Upper Bearing Cap Assembly’ bolts on top to complete the bearing circle.

The parts list is very specific: six units of ‘Camshaft Upper Bearing Cap Assembly – 1 to 6’ (1003070-81د) and one unit of ‘Camshaft Upper Bearing Cap Assembly – 7ذ’ (1003075-81د). For a six-cylinder engine, this indicates seven bearing journals. The six “معيار” caps are for the main journals, while the one “7ذ” cap is different. This is typically the thrust bearing, which has special flanges to control the camshaft’s axial (front-to-back) حركة.

These caps are “line-bored” at the factory, meaning they are machined while bolted to the head. As a result, they are a matched set and are *not* interchangeable. To ensure perfect re-assembly, 14 ‘Dowel Pins’ (1003079-81د) are used to lock the caps in their exact position before the bolts are tightened.

Core Plugs and Gallery Seals

The final items on the list are the seals for the manufacturing passages. The casting process for the complex water jackets leaves several large holes in the side of the FAW مجموعة رأس الاسطوانة. These are sealed by the ‘Cup Plugs’ (CQ72222, CQ72226, CQ7248). قائمة الأجزاء تدعو إلى 13, 20, و 8 وحدات, على التوالى, ما مجموعه 41 plugs of various sizes, sealing the entire coolant system.

على العكس من ذلك, the oil galleries, which feed the valvetrain, are drilled with long, straight bits. The ends of these drilled holes must be sealed. This is the job of the two ‘Inner Hex Tapered Screw Plugs’ (Q61903). These are threaded plugs that seal the high-pressure oil system.

FAW Cylinder Head Assembly Parts List

الجدول التالي يوفر كامل, detailed breakdown of all components identified in the ‘Cylinder Head Assembly’ رسم تخطيطي للجرار FAW CA4251P66K24T1A3E5.

المواصفات الفنية وسياق التجميع

المواصفات ل FAW مجموعة رأس الاسطوانة يتم تعريفها من خلال مجمعها, multi-functional design for a 6-cylinder, 24-valve engine.