Engine Valves & Valve Guides

• Material: European-Made Italian Valve Steel
• Intake Valve Spec: Magnetic Alloy, DIN 1.4718 (BS EN52) Standard
• Exhaust Valve Spec: Non-Magnetic Stellite Alloy, DIN 1.4871 (BS 21-4N) Standard
• Construction: Single-Piece Forged, Weld-Free Architecture
• Stem Finish: Hard Chrome Plated for Friction Reduction and Seal Protection
• Thermal Treatment: Induction Hardened Valve Head/Tip to Resist Heat and Erosion
• Guide Material: Premium Full-Brass Alloy
• Fuel Compatibility: High Resistance to Dry CNG Combustion Heat and Corrosion
• Clearance Consistency: Precision Stem Diameter Tolerances for Optimized Shim Adjustment Range
• Warranty & License: Manufactured under License and Supervision of DAkkS GERMANY

Manufactured in Europe from high-grade Italian valve steel adhering to strict European standards, this valve and valve guide kit provides original equipment (OE) quality for intake and exhaust systems.

• Intake Valves: Engineered from magnetic alloy compliant with DIN 1.4718 (BS EN52) standards.
• Exhaust Valves: Constructed from non-magnetic Stellite alloy conforming to DIN 1.4871 (BS 21-4N), offering extreme thermal and corrosion resistance against dry-burning CNG fuels.

These single-piece, weld-free valves feature induction heat-treated heads for high mechanical strength and erosion resistance. Precision-ground stems coated with a protective chrome layer ensure smooth, silent operation, preventing premature stem wear and valve stem seal degradation. Engineered to resist thermal expansion, warping, and abrasive wear, this set maintains precise shim adjustment range and exact seating angles for optimal cylinder head sealing. Packaged in protective casing, this series is certified under the license and supervision of DAkkS GERMANY.

Main Functions:

• Combustion Chamber Sealing: Seals the cylinder head during compression and combustion phases to prevent pressure loss.
• Airflow & Gas Flow Control: Regulates intake charge entry and exhaust gas scavenging synced via the camshaft mechanism.
• Valvetrain Guidance: High-precision full-brass valve guides maintain linear valve stem travel, preventing lateral displacement and uneven seat wear.
• Thermal Dissipation: Transfers extreme operating heat from valve heads through stems and guides into the cylinder head coolant jacket.
• Oil Metering & Control: Prevents upper valvetrain lubricant from leaking into the combustion chamber via integrated valve stem seals.

Supplementary Documentation: Guide & Maintenance

1. Installation Guidelines:

• Verify Specifications: Always match engine code, stem diameter, and length tolerance before fitting.
• Precision Machining: Replacing valve guides requires professional press tools and cylinder head guide seat reaming.
• Valve Seat Lapping: Lapping the valve face against the head seat is mandatory to guarantee pressure-tight sealing and effective heat transfer.
• Replace Valve Stem Seals: Always install new, high-grade valve stem seals during valve or guide replacement.
• Valvetrain Clearance (Shim Adjustment): Set correct lash clearances between valve stem tips and lifters/rockers to prevent burnt valves or noise.

2. Periodic Inspection:

• Guide Clearance: Inspect lateral stem-to-guide play with valve springs removed; excessive clearance causes oil consumption.
• Visual Inspection: Check valve heads for carbon buildup, cupping, cracks, or burnt margins, and stem surfaces for scoring or heat discoloration.

3. Failure Symptoms & Replacement:

• Symptoms: Cylinder compression loss, excessive oil consumption, blue exhaust smoke, valvetrain ticking noises, power loss, or engine misfires.
• Interval: Valves and guides are heavy-duty components typically replaced during comprehensive cylinder head overhauls (150,000–200,000 km) or immediately upon CNG-related thermal wear.