The exhaust valve seat is a critical component that must withstand extreme temperatures, high-velocity gas flow, and constant impact forces, directly influencing engine power, efficiency, and emissions. The 612630040076 Exhaust Valve Seat from HOWO is engineered to deliver exceptional heat resistance, outstanding wear resistance, and a flawless factory fit, guaranteeing that your engine’s valve train operates with the precision and durability required for heavy-duty diesel applications. As a vital Howo/Sitrak truck parts component, this exhaust valve seat is manufactured from high-grade heat-resistant alloy steel with precision-machined sealing surfaces and a durable, high-temperature coating, providing outstanding resistance to thermal fatigue, corrosion, and mechanical wear. Whether you are performing a cylinder head overhaul or replacing worn valve seats, the 612630040076 guarantees a perfect factory fit, consistent valve sealing, and extended engine life – making it the trusted choice for professional workshops and fleet operators worldwide.
The exhaust valve seat provides the critical sealing surface against which the exhaust valve closes, withstanding the extreme thermal and mechanical stresses of the combustion process. The 612630040076 is specifically designed to endure the harsh conditions of modern turbocharged diesel engines, including exhaust gas temperatures exceeding 750°C, rapid thermal cycling, and the abrasive effects of soot and combustion by-products. A worn or damaged exhaust valve seat can lead to valve leakage, loss of turbocharger boost, reduced power, increased fuel consumption, and elevated emissions. HOWO has engineered this valve seat with a precision-machined 45-degree seating angle and a heat-resistant alloy composition that maintains its hardness and dimensional stability at elevated temperatures. Its robust construction and superior material composition resist deformation and wear, maintaining a consistent seal over thousands of operating hours. With the 612630040076, you restore the original valve train performance, protect your turbocharger, and ensure compliance with emission regulations.
Heat Resistant
Up to 850°C
Wear Resistant
Hardened Alloy
OEM Grade
Genuine HOWO
Precision Angle
45° Seat
The 612630040076 exhaust valve seat is manufactured to the highest OEM standards, incorporating advanced materials and precision engineering. Below are the complete technical specifications for this essential engine component.
| Parameter | Specification | Detail |
|---|---|---|
| OEM Number | 612630040076 | Exact Match |
| Part Name | Exhaust Valve Seat | HOWO Genuine |
| Brand | HOWO | Original Equipment |
| Application | HOWO T7H / A7 / MC11/MC13 | Cylinder head valve train |
| Material | Heat-resistant alloy steel | Heat-treated & hardened |
| Seating Angle | 45° | Precision ground |
| Outer Diameter | 44.5 mm | Press-fit |
| Inner Diameter | 32.0 mm | Valve guide interface |
| Hardness | 45–50 HRC | Wear resistant |
| Temperature Range | -40°C to +850°C | Extreme duty |
| Weight | 0.06 kg | Lightweight |
| Warranty | 12 Months | Manufacturer Guarantee |
The 612630040076 exhaust valve seat is the result of advanced metallurgy and precision machining, combining a high-grade heat-resistant alloy steel formulation with a carefully controlled heat-treatment process. The material is specifically chosen for its exceptional resistance to thermal fatigue and oxidation, maintaining its hardness and dimensional stability at the extreme temperatures encountered in the exhaust system. The seat is precision-turned and ground to achieve the exact outer diameter required for a secure interference fit in the cylinder head, preventing any movement or loosening under the extreme vibration and thermal cycling of engine operation. The 45° seating angle is ground to a mirror finish, providing a perfect sealing surface that minimises valve leakage and ensures optimal compression. The exhaust valve seat also features a generous radius at the valve guide interface to promote smooth gas flow and reduce turbulence. Each seat is inspected for dimensional accuracy, surface finish, and hardness, guaranteeing that the 612630040076 meets HOWO’s stringent quality standards. This meticulous engineering ensures that your engine’s exhaust valves seal perfectly, maintaining turbocharger boost, maximising power, and reducing emissions.
The 612630040076 exhaust valve seat is specifically designed for HOWO heavy-duty trucks equipped with MC11 and MC13 engine families, including T7H, A7, and derivative models. It directly replaces the original valve seat with identical dimensions, seating angle, and material specifications, ensuring a straightforward installation without modifications. The seat is compatible with all factory-specified exhaust valves and valve guides, and it works seamlessly with the original equipment cylinder head. This valve seat is also compatible with many Sinotruk and other commercial vehicles that share the same engine architecture. To confirm fitment, always cross-reference the OEM number on your existing seat with 612630040076. If they match, this component will integrate seamlessly. Keeping these seats in your spare parts inventory enables rapid cylinder head overhauls, minimising downtime and preserving the performance and reliability of your engine.
HOWO T7H
Primary Fitment
HOWO A7
Also Compatible
MC11/MC13
Engine Series
Direct Replacement
No Modifications
Replacing worn or damaged exhaust valve seats with the 612630040076 immediately restores the valve sealing integrity of your engine. The precision-ground seating surface ensures that the exhaust valve closes completely, maintaining optimal compression pressure and preventing the loss of turbocharger boost. This results in improved engine power, better throttle response, and enhanced fuel economy. The superior heat resistance of the alloy steel construction helps prevent valve seat recession and burning, extending the service life of both the valve and the seat. The durable hardened surface resists wear and indentation from the valve’s impact, maintaining the seat geometry over long service intervals. For fleet operators, reliable valve seats reduce the risk of power loss, lower maintenance costs, and help maintain the performance and efficiency of your vehicles. By investing in the 612630040076, you ensure that your HOWO engine delivers the power, reliability, and durability that professional drivers and fleet managers depend on.
Installing the 612630040076 exhaust valve seat is a procedure that should be performed by a qualified engine machinist with the appropriate tools. Begin by thoroughly cleaning the valve seat bore in the cylinder head, removing all old seat material, carbon deposits, and debris. Inspect the bore for any damage or ovality; if damaged, the cylinder head may need to be machined. Chill the new valve seat in a freezer to slightly reduce its outer diameter for easier installation. Using a suitable press and installation tool, carefully press the new seat into the bore until it is fully seated and flush with the cylinder head deck. After installation, use a valve seat cutter to reface the seating surface to the correct 45° angle and ensure concentricity with the valve guide. Install the new exhaust valve and check for proper sealing. Periodically inspect the valve seats for signs of wear or recession during routine maintenance. With proper installation, the 612630040076 will provide years of reliable valve sealing.
Pro Tip: When replacing valve seats, it is recommended to replace all intake and exhaust valve seats as a set to ensure consistent valve train geometry and performance. The 612630040076 is available individually; order the required quantity for a complete cylinder head set.
Genuine HOWO components are engineered to the highest standards, and the 612630040076 exhaust valve seat is no exception. Aftermarket valve seats often use inferior alloys, inconsistent hardness, or imprecise seating angles, leading to premature wear, valve leakage, and potential engine damage. HOWO’s valve seat is manufactured using the same materials and processes as the original equipment, guaranteeing a perfect fit and reliable performance. By choosing the 612630040076, you benefit from HOWO’s rigorous testing, including wear resistance, thermal cycling, and dimensional accuracy tests. This ensures that the valve seat meets the demanding requirements of heavy-duty trucking. Moreover, genuine parts are backed by a comprehensive warranty and supported by HOWO’s global network, giving you confidence in your purchase.
OEM Authentic
Factory Quality
Long Service
Extended Life
Global Standard
Trusted Worldwide
Q: Which vehicles use the 612630040076 exhaust valve seat?
A: The 612630040076 is designed for HOWO T7H, A7, and other models with MC11/MC13 engines, as well as many Sinotruk trucks with the same cylinder head architecture.
Q: What are the symptoms of a worn exhaust valve seat?
A: Loss of engine power, rough idle, reduced fuel economy, hard starting, excessive exhaust emissions, and a noticeable loss of turbocharger boost are common indicators of worn exhaust valve seats.
Q: Can I reuse the old valve seat after grinding?
A: If the valve seat is worn beyond the service limit or has been ground multiple times, it is recommended to replace it with a new 612630040076. Reusing a seat that is too thin can lead to valve recession and seat failure.
Q: How do I verify the correct part?
A: Check the OEM number on your existing valve seat. If it matches 612630040076, this is the exact replacement. Consult your vehicle’s parts manual for additional confirmation.
Order your 612630040076 Exhaust Valve Seat today! Explore our complete selection of genuine HOWO and Sinotruk engine components at Howo/Sitrak truck parts and keep your valve train sealed for maximum performance.
The 612630040076 Exhaust Valve Seat from HOWO is a testament to precision engineering and uncompromising quality. By choosing this genuine component, you ensure that your engine’s exhaust valves seal perfectly, maintaining turbocharger boost, maximising power, and reducing emissions. Whether you are a professional engine builder or a fleet manager, this valve seat offers the performance, reliability, and exact fit that you can count on. Trust HOWO – the benchmark for excellence in heavy-duty truck components – and experience the difference that genuine quality makes.
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