The Cylinder block for HOWO MAX 4X2 tractor is the foundation of the engine’s combustion chamber and water jacket. This robust casting is made from high‑strength alloy iron, ensuring durability under heavy loads. When you need reliable HOWO Parts, this component guarantees precise cylinder bore alignment and cooling efficiency. Below are detailed descriptions of every sealing and fastening component that works with this engine block.
Four screw plugs seal oil galleries and coolant passages in the Cylinder block. These plugs prevent leaks and maintain proper pressure within the unit.
Fifteen bowl‑shaped plugs of 25/20mm diameter cover core holes in the Cylinder block. They secure against vibration and thermal expansion, keeping debris out of the water jacket.
Thirty‑eight bowl‑shaped plugs of 32/30mm diameter seal larger openings in the engine block. Their deep cup design withstands high coolant pressure without dislodging.
Three bowl plugs of 40/15mm diameter close the main coolant passages near the rear of the Cylinder block. They are made of corrosion‑resistant steel for long service life.
Fourteen flange hexagon bolts (M8x35, strength grade 8.8) secure the cylinder head and accessories to the Cylinder block. Their flange spreads clamping force evenly, preventing gasket failure.
Our Cylinder block is manufactured using high‑chromium gray iron with nodular graphite. This composition resists cylinder bore wear and prevents cracking under high combustion pressure. The unit undergoes 100% X‑ray inspection to eliminate porosity.
Each engine block is machined on a five‑axis CNC line. Deck flatness is held to 0.03mm, and cylinder bore roundness to 0.01mm. This precision ensures perfect head gasket sealing and oil control ring performance.
The Cylinder block features a redesigned water jacket that distributes coolant evenly around all six cylinders. This reduces hot spots and extends head gasket life. The block also includes integrated oil drain passages.
Our Cylinder block has sufficient wall thickness to accept +0.5mm and +1.0mm oversize pistons. This allows the casting to be rebuilt up to three times, lowering life‑cycle cost for fleet operators.
The Cylinder block for the HOWO MAX 4X2 engine is produced using the lost‑foam casting process. This technique ensures consistent wall thickness and eliminates sand inclusions. After casting, the block is stress‑relieved in a controlled furnace to remove internal tensions. The main bearing bores are line‑honed together with the bedplate, guaranteeing perfect crankshaft alignment. Every block is pressure‑tested at 6 bar to verify coolant jacket integrity. Only units that pass all checks are marked with a final inspection stamp.
The Cylinder block incorporates replaceable wet cylinder liners, which can be extracted without removing the engine from the chassis. This service feature is critical for in‑frame overhauls. The liner counterbores are machined with a 0.05mm interference fit to prevent liner fretting. Additionally, the block has a built‑in crankcase ventilation gallery that reduces oil mist carryover. This design not only improves engine cleanliness but also lowers oil consumption by 15% compared to earlier HOWO engine blocks.
On the external side, the engine block features reinforced side walls to mount the air compressor, power steering pump, and alternator. The mounting bosses are drilled and tapped to exact OEM specifications, so aftermarket accessories bolt on without adapter plates. The block also includes a rear mounting flange that is compatible with both manual and automated manual transmissions. Dowel pins are pre‑installed to ensure transmission alignment within 0.1mm. This level of detail makes the unit a true drop‑in replacement.
Thermal management is a key strength of this casting. Internal cooling jets are machined directly into the block to spray oil onto the underside of each piston. Those jets are calibrated to activate at 2.5 bar oil pressure, providing immediate cooling during high‑load climbs. The block also has an integrated water outlet housing that directs coolant to the radiator without external pipes. By reducing external connections, the unit minimizes potential leak points. Over 5,000 hours of dynamometer testing have proven the durability of this engine block under full‑load conditions.
When installing a new Cylinder block, always use fresh head bolts and follow the torque‑angle procedure. The block threads for head bolts are rolled, not cut, to maintain strength. Lubricate the bolt threads with engine oil before torquing. The tightening sequence must start from the center and spiral outward. Final angle tightening of 90° plus 90° is required for the M18 bolts. Failure to follow this pattern may distort the block deck, leading to head gasket leakage.
Before installing pistons, inspect the cylinder bore surface for any scratches or rust. The factory finish is plateau honed to a 0.4 Ra value. Use a telescoping gauge to measure bore taper and ovality; the maximum allowable variation is 0.03mm. If the block requires honing due to minor damage, use a rigid hone with 400‑grit stones. Do not use a ball hone as it can remove the plateau finish. After honing, thoroughly clean the block with hot soapy water and blow dry with compressed air to remove all abrasive residue.
The Cylinder block’s expansion plugs (the bowl‑shaped plugs listed above) must be replaced every time the block is rebuilt. Apply a thin bead of anaerobic sealant to the plug seat before driving them in. Use a drift that matches the plug diameter to avoid distortion. For the 40mm plug, a depth stop is required to set it 2mm below the block surface. After installation, pressure test the coolant side of the block again to verify seal integrity. Neglecting new plugs can cause sudden coolant loss and engine overheating.
Regular maintenance of the Cylinder block includes checking for external coolant weeps around the plug locations and the water pump mounting face. A visual inspection every 50,000 km is recommended. If you notice oil in the coolant or coolant in the oil, perform a cylinder leak‑down test to identify a cracked block. Cracks in the engine block are rare but usually occur between cylinder liner bores or near the main bearing webs. Such cracks are not repairable; the block must be replaced. Always keep the engine coolant with proper antifreeze concentration to prevent cavitation erosion inside the block.
Q: Does the Cylinder block fit both Euro 2 and Euro 3 versions of HOWO MAX? Yes, this block is dimensionally identical for both emission standards. However, Euro 3 engines have additional drillings for the EGR cooler; if you are installing on a Euro 2 engine, those ports must be plugged with the included screw plugs.
Q: Can I use the old Cylinder block bolts again? No, all head bolts and main bearing bolts must be replaced when installing a new block. Torque‑to‑yield bolts permanently stretch and lose clamping force if reused.
Q: What is the warranty on the Cylinder block? The engine block comes with a 12‑month unlimited mileage warranty against casting defects and premature wear. The warranty does not cover damage caused by improper installation or lack of coolant.
Q: Does the Cylinder block include the main bearing caps? Yes, the block is supplied with the cast iron main bearing caps and the four main bolts. The caps are machined as a set with the block and are not interchangeable with other blocks.
Q: How heavy is the Cylinder block? The bare block weighs approximately 240 kg. Freight shipping requires a pallet with a reinforced wooden crate. Lift points are clearly marked on the block to avoid damage to machined surfaces.
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