4298234 Cummins X15 / ISX15 Single Cam CGI Fire-Ring Loaded Cylinder Head – New, Stage 6 Inconel
| Brand | JAK's Diesel |
| Part Category | Cylinder Heads |
| Engine Make | Cummins |
| Engine Model | X15 · ISX15 · ISX |
| Condition | New |
| Stage / Tier | Stage 6 |
Our top-tier Stage 6 head for the Cummins X15 and ISX15 single overhead cam, built to replace Cummins 4298234 / 5658294. It combines a compacted graphite iron (CGI) casting, fire-ringed combustion seals and Inconel valves for high-horsepower, high-cylinder-pressure builds. It arrives assembled and ready to bolt on, with no core to send back.
What's Included
- New CGI (compacted graphite iron) cylinder head casting, fire-ringed
- New intake and exhaust valves (Stage 6 — Inconel valves)
- New valve springs, retainers and keepers
- Valve guides and valve stem seals installed
Not included: head gasket set, head bolts, injectors, rocker assemblies. You will need a fire-ring head gasket — ask us and we will quote it with your head.
Specifications
| Replaces | Cummins 4298234, 5658294 and cross-references below |
| Engine | Cummins X15 / ISX15 single cam (SOHC) |
| Condition | New — no core |
| Assembly | Loaded (valves, springs, retainers, keepers, guides, seals) |
| Valve package | Stage 6 — Inconel valves |
| Casting | CGI (compacted graphite iron) |
| Combustion seal | Fire-ringed — requires a fire-ring head gasket |
| Brand | JAK's Diesel |
Also available: Stage 2 and Stage 3 X15 heads.
Fitment
Fits Cummins X15 and ISX15 single overhead cam engines (CM871 / CM2250 / CM2350). It does not fit dual-cam ISX engines. We confirm fitment by engine serial number (ESN) or casting number before every head ships.
Replaces / Cross-Reference Part Numbers
OEM and reman numbers: 4298234, 4298235, 4298236, 4298237, 4298238, 5658294, 4386009, 3686431, 3686432, 3686434, 3686660, 3686774, 3686880, 3686881, 3687398, 3687607, 3688754, 3688755, 3688759, 3688761, 3688800, 3691250, 3691253, 4356434, 4374091, 5394197, 5394198, 5628269, 5658302, 5658309, 5708760
Shipping, Core & Warranty
- No core charge, no core return. This is a new casting, not an exchange unit.
- Freight: ships crated by LTL freight. Freight is free to a commercial address with a forklift or dock. Residential, liftgate and terminal delivery can be quoted — call before you order.
- Local pickup: available in Henderson, CO by arrangement.
- Warranty: 1 year against defects in materials and workmanship.
Frequently Asked Questions
Is this head new or remanufactured?
New. It is a new casting assembled with new valvetrain components — not a rebuilt core.
Do I have to send back a core?
No. There is no core charge and nothing to return.
What else do I need to install it?
Plan on a new head gasket set and head bolts for the X15. They are not included. Message us and we will match the right kit to your engine serial number.
How do I confirm it fits my X15?
Send us your engine serial number (ESN) or the casting number from your old head. We verify fitment against 4298234 before the head ships.
Does a fire-ring head need a special head gasket?
Yes. A fire-ringed head must be paired with a matching fire-ring head gasket. It is sold separately — ask us and we will quote the correct gasket with your head.
What is a CGI cylinder head?
CGI is compacted graphite iron. It is stronger and more resistant to cracking from heat cycling than standard gray-iron castings, which is why it is used on high-output and high-EGT builds.
How long does delivery take?
Heads are crated and handed to the LTL carrier in 1–2 business days. Transit is typically 2–5 business days depending on your location.
Questions? Call JAK's Diesel at (720) 445-6249. See all Cummins ISX / X15 parts, performance heads or diesel cylinder heads.
Discovery models are listed below. Confirm the complete application and any ESN/CPL or size restrictions before ordering.