FuseTech
4J Head Bolt Set - 4JJ1 / 4JK1 / 4JJ3 - Fuse Tech
4J Head Bolt Set - 4JJ1 / 4JK1 / 4JJ3 - Fuse Tech
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🔩 4J Heavy Duty Head Bolt Set (18 pc) - 4JJ1 / 4JK1 / 4JJ3
Direct-Fit Clamping Insurance for Boosted 4J Builds | FuseTech
Every time the head comes off a 4J, the bolts go in the bin. Put better ones back in.
The factory Isuzu head bolts are torque-to-yield: they stretch to their limit on installation and are strictly single-use. Add boost, fuel and cylinder pressure on a tuned 4JJ1 or 4JJ3 and those factory fasteners are working at the top of their range. This FuseTech heavy duty head bolt set is a direct-fit upgrade that threads straight into the factory block: no drilling, no tapping, no machining under the rocker assembly. If you are doing a head gasket, a rebuild, or stepping up the tune, this is the smart set to fit while you are in there.
⚠️ INSTALLATION: Professional installation recommended. Always fit a new head gasket, follow the factory tightening sequence, and use the FuseTech-supplied torque specification, not the OEM torque-to-yield procedure.
| Spec Snapshot | |
|---|---|
| Set contents | 18 x cylinder head bolts (full engine set) |
| Thread | M11 x 1.5 (factory head bolt thread) |
| Replaces OE | 8-98201019-0 (supersedes 8-97144583-0 / -1 / -2) |
| Engine fitment | 4JJ1-TC / 4JJ1-TCX (incl. DPF), 4JK1, 4JX1, 4JJ3 |
| Installation | Direct fit into factory block threads, no machining required |
| Brand | FuseTech Performance |
✅ Key Features
- 🔩 Full 18-Bolt Set: Every head bolt for one engine, one box, done
- 🧩 Whole 4J Family: One set covers 4JJ1, 4JK1, 4JX1 and 4JJ3 (all 18 bolts are identical across the platform)
- 🛠️ Direct Fit: Threads into the factory M11 x 1.5 block threads, unlike stud kits which require tapping the block and clearance work under the rockers
- 🔥 Built for Boosted Builds: Engineered for tuned engines running elevated cylinder pressure
- 💡 Fit While You're In There: Factory bolts must be replaced any time the head is removed, so upgrading costs you zero extra labour
🔧 Vehicle Compatibility
- Isuzu D-MAX - 4JJ1-TC / 4JJ1-TCX (2007-2020, incl. DPF models)
- Isuzu D-MAX RG / MU-X - 4JJ3 (2020+)
- Isuzu MU-X - 4JJ1-TC / TCX (2013-2021)
- Holden Colorado RC / Rodeo RA7 - 4JJ1-TC
- Mazda BT-50 TF - 4JJ3 (2020+)
- Isuzu D-MAX 2.5 - 4JK1 | Jackaroo / Trooper - 4JX1
Good news: Isuzu used the same 18-bolt head fastener design across the whole common rail 4J family, so there is no early/late split to worry about. Message us with your VIN if unsure.
📦 What's Included
- 18 x FuseTech Heavy Duty Cylinder Head Bolts
Head gasket not included. Always fit a new head gasket when refitting the cylinder head.
🛠️ Installation & Requirements
- Professional installation recommended for any cylinder head work
- Clean block threads fully before installation and follow the factory tightening sequence
- Torque to the FuseTech-supplied specification (do not use the OEM torque-to-yield angle procedure)
- Pair with a new head gasket, graded to piston projection per the workshop manual
- Contact us to confirm stock availability if timing is critical
🛡️ Warranty & Returns
Covered under our standard policy. See our Refund, Returns & Warranty Policy for full terms.
💳 Payment & Shipping Options
- 💸 Buy Now, Pay Later: Afterpay, Humm, Klarna & Zip available
- ✈️ Free Express Shipping Australia-Wide
- 📦 Diesel performance specialists, not general parts resellers
❓ Frequently Asked Questions
Q: Will these fit my 2012-2019 D-Max 4JJ1?
A: Yes. This set fits every common rail 4JJ1, from early alloy rocker cover engines through to the DPF-era 4JJ1-TCX, plus the 4JK1, 4JX1 and current 4JJ3.
Q: What OE part number do these replace?
A: Isuzu 8-98201019-0, which superseded 8-97144583-0, -1 and -2. All are the same bolt design, and a full set is 18 identical bolts.
Q: Can I reuse my factory head bolts instead?
A: No. Factory bolts are torque-to-yield and single-use only. Isuzu specifies new bolts every time the head is fitted, which makes head work the perfect time to upgrade.
Q: Head bolts or head studs, which should I run?
A: Studs deliver maximum clamp but the 4JJ1 stud install requires tapping the block threads deeper and clearance work where the outer studs sit under the rocker assembly. These bolts are a straight drop-in, so they suit builds where you want an upgrade over factory without machining.
Q: Why upgrade head bolts on a tuned 4JJ1 or 4JJ3?
A: More boost and fuel means more cylinder pressure pushing up on the head. Upgraded fasteners help maintain head gasket clamp on hardworking tuned engines, cheap insurance compared to a lifted head.
⚡ LOCK THAT HEAD DOWN
FuseTech heavy duty 18-bolt head set for the full 4J family. Direct fit, no machining. Fit them while the head is off.
Disclaimer: Common Rail Cowboys is not affiliated with Isuzu Motors, Mazda Motor Corporation, or General Motors Holden. OE part numbers are shown for cross-reference only. Installation should be performed by a qualified technician. Fitment verification and correct torque procedure are the buyer's responsibility.
