Description
DNJ Engine Piston Ring Sets are precision-engineered to provide a reliable seal between the piston and cylinder wall in internal combustion engines. Each set includes a complete set of rings required to service every piston in the engine, ensuring consistent performance across all cylinders. Typical configurations include top compression rings, second (wiper) rings, and oil control ringsdesigned to optimize compression retention, regulate oil consumption, and support effective heat transfer. DNJ Engine Piston Ring Sets are manufactured from high-quality cast iron or steel alloys for exceptional strength, wear resistance, and thermal stability. Advanced surface treatments such as chrome plating, molybdenum coating, or nitriding are applied to improve sealing performance, reduce friction, and extend service life under extreme engine conditions. DNJ Engine Piston Ring Sets are manufactured to meet or exceed OEM quality standards. DNJ also offers a full line of related components including pistons, connecting rod bearing sets, crankshaft main bearing sets, complete engine rebuild kits, and moreensuring full compatibility and performance across engine systems. With precision engineering and top-tier materials, DNJ Engine Piston Ring Sets deliver exceptional performance and long-lasting durability.
Process & Warranty
Cylinder Head Rebuilding Process
1. Initial Inspection: As a unit comes to our shop, we give it an initial inspection to determine whether there is any reason the head should not proceed to rebuilding. This quickly catches problems such as cracks, casting damage and other conditions that would halt the process for that casting.
2. Teardown: The cylinder head is fully disassembled, which reveals other areas of potential damage to the casting. The parts and the head are separated and go through different cleaning processes.
3. Cleaning: Cast iron heads are cleaned in a thermal cleaning system — baked at 600° to reduce grease and oil to ash, then put through a steel-shot machine for a brilliant finish. Aluminum heads are baked at a lower temperature or put through a high-pressure wash, then glass-beaded.
4. Head Inspection: After cleaning, heads are pressure tested or Magnafluxed to find any cracks. All bolt holes, valve guides, valve seats and other areas are inspected for broken bolts, broken taps, cracked guides and other impairments. Straightness and cam bore wear are also checked.
5. Machining: All heads have guides installed to meet OE conditions and are resurfaced to far exceed factory specifications for surface finish. A three-angle valve job achieves valve seat runout under .001". Valves are ground for a perfect seal between valve and seat.
6. Assembly: New OE-style valve guide seals are installed. Springs are tested for proper seat pressure. Valve seat sealing is vacuum-checked for an airtight fit. Lifters are bled and rebuilt for zero lash after startup. Cams are polished and clearances are checked twice to meet OE oil clearances.
7. Final Inspection: Every head is visually inspected — surface finish, lash, bolt holes and all other areas — to ensure a quality cylinder head.
Questions about our cylinder head services? Call 1-866-766-9955.
Warranty — 12 months from purchase
Match the head before installation. We will not warranty an incorrectly installed head. Call us immediately with any questions or concerns about your purchase.
First 3 months:
- Repair or replacement of the cylinder head.
- Gasket set supplied for reinstallation.
- Labor calculated from book time at $25.00 per hour, up to a maximum of 10 hours.
- Replacement of fluids and filters.
Remaining 9 months:
- Repair or replacement of the cylinder head.
- Gasket set supplied for reinstallation.
- Replacement of fluids and filters.
- No labor is covered.
Warranty is void if:
- The head was improperly installed.
- The head was overheated (heat tab melted or missing).
- The head received insufficient oiling.
- The cooling system operated improperly.
Warranty returns must be sent to Allied Motor Parts uncleaned and fully assembled — any disassembly voids the warranty — and must be accompanied by proof of purchase. There is no warranty on threaded bolt holes after installation.
This warranty is in lieu of any other warranty, expressed or implied, including any implied warranty of merchantability or fitness for a particular purpose.
Quality Assurance
Here’s why our cylinder heads stand out:
Thorough Inspection: Every head undergoes a complete teardown, cleaning, and detailed inspection for cracks and imperfections.
Advanced Cleaning: Thermal cleaning for cast iron and high-pressure washing for aluminum ensures a brilliant finish.
Precision Machining: CBN resurfacing, triple-angle valve cuts, and guide installations exceed OEM specifications.
Rigorous Testing: Vacuum tests, tension checks, and pressure tests guarantee performance and durability.
High-Quality Components: New seals, plugs, and rebuilt lifters ensure optimal functionality.
Final Assurance: Each head is inspected, stamped, and stored in a climate-controlled environment.
Wide Availability: Over 2,000 cylinder heads for all makes and models, ready for repair or exchange.