Industrial Injection Premium Stock Plus Cylinder Head 12-Valve With Fire Ring Groove 89-98 Ram 5.9L Cummins

Thinking about upgrading to Fire Rings in your 12-Valve Cummins? Radius-cut fire ring grooves create a stronger, more reliable combustion seal, allowing a 12-Valve Cummins engine to handle higher boost and cylinder pressure without head gasket failure. If you are planning on pushing your Cummins power to the limit, ensure your engine can withstand the extra stress that higher-performing injectors and fuel systems can impose with a cylinder head designed to handle it. Get an affordable and reliable upgraded head with Industrial Injection's Premium Stock Plus Cylinder Head.

NOTE: Fire Ring Head Gasket Sold Separately. Installation of a fire ring gasket requires high yield head studs to ensure proper seat of the head to the cylinder block.

Precision Remanufacturing Process for Cylinder Heads

Every remanufactured cylinder head undergoes a detailed cleaning, inspection, and machining process to ensure it meets strict quality standards for diesel engine performance, durability, and reliability. This comprehensive remanufacturing process helps restore the strength and efficiency expected from a Cummins diesel engine.

Thorough Cleaning & Inspection

Each cylinder head begins with a deep cleaning process to remove contaminants and prepare the casting for inspection and machining.

• High-pressure jet washing removes oil, grease, and debris
• Glass bead blasting eliminates carbon buildup from the casting
• Magnaflux inspection (for cast iron heads) detects hidden cracks
• Pressure testing verifies structural integrity
• Visual inspection ensures the casting is free of defects

Valve guides and valve seats are removed as needed to prepare the cylinder head for machining or port work.

Upgraded Heat-Treated Valve Guides

New high-strength alloy valve guides are installed to improve durability and longevity in demanding diesel engine environments. These guides are heat treated to Rockwell 22 “C” scale, delivering exceptional wear resistance that exceeds many factory materials, including bronze.

Each valve guide also features a precision spiral groove designed to retain oil and improve valve stem lubrication during engine operation.

Precision Diamond Honed Valve Guides

Instead of traditional reaming, the valve guides are precision honed using diamond abrasives. Diamond honing ensures consistent accuracy across every cylinder head.

This process provides:

• Exact valve guide sizing
• Consistent bore geometry
• Smooth internal surface finish
• Improved valve alignment and longevity

Each guide is verified using a valve guide bore gauge to ensure proper tolerances.

Multi-Angle Performance Valve Job

To improve airflow and combustion efficiency, the cylinder head receives a precision multi-angle valve job using a Serdi 100 guide and seat machine.

The Serdi system uses a solid carbide straight shank pilot inserted into the valve guide to simulate the valve stem during machining. This process ensures perfect alignment between the valve seat and valve face, creating an optimal seal and maximizing airflow in and out of the cylinder head.

Precision Cylinder Head Surfacing

Each cylinder head is resurfaced using CBN or diamond tooling on a Berco milling machine. This machining process restores a perfectly flat sealing surface and allows technicians to control the finish based on the head gasket being used.

For example, MLS (Multi-Layer Steel) head gaskets require an extremely smooth surface finish to ensure proper sealing in high-pressure diesel engines.

Final Assembly

Once all machining processes are complete, the cylinder head is:

• Jet washed again for final cleaning
• Thoroughly dried
• Assembled with new valve seals
• Equipped with new performance valve springs

The result is a high-quality remanufactured diesel cylinder head built for dependable performance in demanding Cummins engine applications.