Product Description
Genuine Cummins
Cummins 3906854 — Intake Valve Seat Insert for 5.9L 12-Valve (6BT)
MPN: 3906854 | Also Known As: valve insert, valve seat (intake) | Pairs With: 3904105 (exhaust valve seat insert)
Why This Part
- ✓ OE intake seat insert for proper valve sealing and compression.
- ✓ Direct-fit for 5.9L 12-valve cylinder heads (6 required for intake side).
- ✓ Hardened material resists recession and heat fatigue.
- ✓ Ideal during head rebuilds, dropped-seat repairs, or performance refresh.
OE Fit Engine Rebuild Use 6 (Intake)
Quick Specs
| Type | Intake valve seat insert (valve insert) |
|---|---|
| OE Part # | 3906854 |
| Qty Required | 6 per engine (intake only). For a full set include 6× 3904105 (exhaust). |
| Applications | Cummins B-Series 4BT/6BT; 5.9L 12-valve automotive (see fitment) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1989–1998 | Ram 5.9L Cummins 12-Valve (VE & P7100) | Ram 2500/3500 |
Industrial/Off-Highway: Common on 4BT 3.9 & 6BT 5.9 B-Series; verify by ESN.
Often Paired With
- Exhaust Seat Insert: Cummins 3904105 (use 6)
- Valve Guides: 3904408 (60.5 mm), 3904409 (51.75 mm)
- Complete Valve Job: valves, springs, seals, and machine-shop install
What’s In The Box
- (1) Genuine Cummins Intake Valve Seat Insert (3906854)
- Other seats/guides sold separately (see “Often Paired With”).
Install Tips
- This is a machine-in component—professional cylinder-head machining is recommended.
- Confirm seat interference fit & depth; cut 3-angle/seat to spec after install.
- Check concentricity, valve protrusion, and lash per Cummins procedures.
FAQ
WILL THIS FIT MY 1989–1998 5.9L 12-VALVE CUMMINS RAM?Yes—3906854 is the intake valve seat insert used on 5.9L 12-valve heads (VE & P7100). Always confirm by ESN or head casting.
HOW MANY SEATS DO I NEED?Use 6× 3906854 for the intake side. For a complete head you’ll also need 6× 3904105 exhaust seats.
IS THIS FOR INTAKE OR EXHAUST?3906854 is the intake seat insert. The typical companion exhaust seat is 3904105.
DO I NEED A MACHINE SHOP TO INSTALL?Yes—seat inserts require proper machining/press fit and seat cutting for reliable sealing and valve life.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins valve insert for B-Series applications.
