Loaded Cylinder Head for Cummins 6BT 5.9 12 Valve Diesel
Loaded Cylinder Head for Cummins 6BT 5.9 12 Valve Diesel
Overview
Brand-new loaded cylinder head for the Cummins 6B, 6BT and 6BTA 5.9L 12-valve diesel - a complete assembly that seals the combustion chamber and carries the valves, springs, injectors and rocker assembly on these engines. This is the 12-valve head, two valves per cylinder, used with the mechanical rotary and P7100 injection pumps. One casting covers all six cylinders, so a complete engine takes just one. It ships fully assembled with the valvetrain installed and the valves lapped, so there is no machine shop time before you bolt it on.
Includes: Valves, valve springs, valve stem seals and keepers - all installed, with the valves lapped so they are ready to seal. Injector bores are cut to the 7mm specification.
Fitment
| Engine | Fits the Cummins 6B, 6BT, 6BTA and 6B5.9 5.9L inline 6-cylinder 12-valve diesel (2 valves per cylinder) with mechanical injection pump |
| Engine Years | 1989-1998 for on-highway use in the Dodge Ram pickups listed below; the industrial, agricultural, marine and generator set versions of the 12-valve 5.9 began in the mid 1980s and many stayed in production for years after that |
| Vehicle | Fits Dodge Ram 2500 and Ram 3500 pickups |
| Vehicle Years | 1989-1998 (1989-1991 non-intercooled with the VE rotary pump, 1991.5-1993 intercooled with the VE pump, 1994-1998 with the P7100 inline pump) |
| Application | Fits medium duty trucks, buses and step vans built with the mechanical 12-valve B5.9, including FL50, FL60, FL70 and FL80 trucks and MT35 step vans; fits Freightliner FS65 school bus chassis with the mechanical engine; fits Case IH Maxxum 5140, 5150 and 5200 series tractors; fits Hyundai 9S machines running the HM5.9 (B5.9) Tier 2 engine, including the R210W-9S and R260LC-9S excavators; fits 40-100 kW generator sets, water pumps, road rollers, pavers and other industrial equipment powered by the mechanical 5.9 |
| Replaces | 3967458, 3967448, 3967459, 3967454, 3966454, 3966452, 3966451, 3934783, 3934768, 3934747, 3934746, 3934742, 3934730, 3930933, 3930652, 3930421, 3927300, 3925400, 3925391, 3925389, 3917287, 3913391, 3910276, 3863606, 3802805, 3802804, 3802340, J966454, J925400 |
Why It's Better
- Brand-new casting - a new head with no heat-cycle history, never welded, never re-decked and with no repaired cracks
- Complete new valvetrain - valves, springs, valve stem seals and keepers installed, with the valves lapped so they are ready to seal
- Machined to the current 7mm injector bore specification - the updated design that replaced the early 9mm bore heads and ended the cracking they were known for
- Pressure tested and vacuum checked, with the deck and manifold faces machined flat for a clean gasket seal
Specifications
| Material | Cast iron, brand-new casting |
| Valvetrain | OHV, 2 valves per cylinder (12 valves total), solid lifters |
| Injector Bore | 7mm |
| Injection Pump | Mechanical - VE rotary pump (1989-1993) or P7100 inline pump (1994-1998) |
| Displacement | 5.9L (359 cu in), 102 x 120 mm bore and stroke, 17.0:1 compression |
| Condition | New aftermarket replacement |
| Quantity Per Engine | 1 (one-piece head, covers all 6 cylinders) |
| Warranty | 12 months |
Shipping & Warranty
Free shipping within the continental USA. In-stock orders are processed within 1-2 business days.
Buying by the pallet? Quantity discounts are available - send us the part number and the quantity you need and we will come back with tiered pricing and lead time.
Backed by a 12-month warranty against manufacturing defects.
Frequently Asked Questions
Q: Is this for the 12-valve engine or the 24-valve?
This head is for the 12-valve 5.9 only. It does not fit the 24-valve 5.9 ISB (1998.5-2002 with the VP44 pump, and 2003-2007 common rail), the 6.7L ISB or QSB, the 8.3L ISC or QSC, the 8.9L ISL or QSL, or the 4BT 3.9 four-cylinder. The quickest check is the valve cover: six separate small covers means a 12-valve engine and this head fits; one full-length cover means a 24-valve and it does not.
Q: Do I need different injectors?
The injector bores in this head are cut to the current 7mm specification. If your truck still has its original pre-1992 head with the older 9mm bores and the 9mm injectors that went with it, those injectors will not seat in this head - you need the 7mm injectors used from 1992 on. Tell us your year and we will point you at the right set.
Q: How do I confirm it fits?
Match the number cast into your original head against the Replaces list above, or send us your engine serial number and CPL number and we will verify the arrangement before shipping. The 12-valve 5.9 was built in many ratings and CPL configurations, so the serial number is the fastest way to confirm.
Q: How many do I need?
One. This is a single one-piece head that covers all six cylinders, so a complete engine takes just 1 cylinder head.
Q: What equipment does this cylinder head fit?
It fits Dodge Ram 2500 and Ram 3500 pickups from 1989 to 1998. It also fits Freightliner FL50, FL60, FL70 and FL80 trucks and MT35 step vans, fits Case IH Maxxum 5140, 5150 and 5200 series tractors and fits Hyundai 9S machines running the HM5.9 (B5.9) Tier 2 engine, such as the R210W-9S and R260LC-9S excavators - all with the mechanical 12-valve engine.
Q: Can I reuse my original head bolts, and what do they torque to?
Use new bolts - they are torque-to-yield and single-use. The sequence for the 6 bolts per cylinder is 66 ft-lb on all bolts, then 89 ft-lb on the long rocker arm bolts, then a final 90 degree turn on all of them. Fit a new head gasket at the same time. If you are having your original head measured instead of replaced, the service limit for head thickness is 94.75 mm.
This is an aftermarket replacement part. We are not affiliated with, authorized by, or endorsed by the original equipment manufacturer. All trademarks and brand names are the property of their respective owners and are used for reference purposes only.