Atomic Barra Heavy Duty Timing Chain Kits

Atomic Heavy Duty Timing Chain Kit – Ford Barra DOHC | Complete or Partial Kits

Description:
Whether you're refreshing a factory engine or building a 1500hp monster, the Atomic Heavy Duty Timing Chain Kit has everything you need to confidently replace the entire timing system on any Ford Barra DOHC 6-cylinder engine.

This is not just a chain and tensioner kit — it’s a fully engineered solution built for serious performance. Featuring a heavy-duty chain, a hardened billet curved guide, new billet hardened steel crank sprocket, genuine Ford tensioner, and all required guides, bolts, gaskets, and seals, this kit is trusted in both street and full race applications.

We’ve refined every component to survive extreme RPM, big cams, stiff valve springs, and heavy-duty use — with detailed installation instructions included below to make your timing system upgrade precise and stress-free.

NOTE: This kit is designed to accommodate head gasket thicknesses up to 1.2mm. Some setups with thick headgaskets may over tension the chain or not allow for proper tensioner operation. 

✅ Key Features:

✅ Suits all Ford Barra DOHC 4.0L 6-cylinder engines (BA–FGX)
✅ Built for everything from stock rebuilds to 1500hp performance builds
✅ Includes Atomic Heavy Duty Timing Chain – ~2x strength vs factory
✅ Billet steel curved guide – heat treated, unbreakable, and tip reprofiled to prevent plastic failure
✅ Billet crank sprocket – case-hardened, heat treated, and tighter tolerance for reduced vibration
✅ Billet chromoly pivot bolt for added durability
✅ New top guide and straight guide
✅ Genuine Ford OEM hydraulic chain tensioner
✅ All necessary seals and gaskets included
✅ Full installation instructions included for DIY or pro use

🛠️ Why Choose the Atomic Timing Chain Kit?

✔️ Replaces every critical timing component in one complete package
✔️ Designed to prevent common Barra timing failures (chain stretch, guide breakage, sprocket wear)
✔️ Billet and heat-treated components ensure long-term reliability under power
✔️ Precision fitment and proven durability in street, dyno, and strip builds
✔️ The same billet guide design everyone else copied — we just perfected it

📦 What’s Included in a FULL kit:

• 1x Atomic Heavy Duty Timing Chain

• 1x OEM Ford Chain Tensioner with m6 bolts and washers

• 1x Billet Curved Guide with new plastic (heat treated & reprofiled tip)

• 1x Top Guide 

• 1x Passenger side three bolt guide 

• 1x Billet Case-Hardened Crank Sprocket

• 1x Billet Chromoly Pivot Bolt with nyloc nut

• Gaskets and Seals

Instructions for installation of #306620 H/Duty Timing Chain.

Thank you for purchasing an Atomic H/Duty timing chain. It has been designed to withstand the rigours of high-performance usage and to enjoy trouble free operation, it is imperative the chain is installed correctly - failure to follow these instructions will lead to ineffective operation and the possibility of severe engine damage.

Step 1.

Remove the rocker cover, coil packs, spark plugs and front timing cover from the engine and rotate until the factory timing links (yellow/gold colour) are lined up with the corresponding marks on the VCT sprockets and the crankshaft sprocket. This may take up to 36 revolutions of the motor until the chain is phased correctly with the timing marks on all 3 sprockets. Refer pics #2, #3 and #4.

Step 2.

Undo the timing chain tensioner and release the driver’s side guide. This will release the timing chain. Remove the chain and crank sprocket and set aside. The crank sprocket simply slides off the snout of the crank.

Step 3.

Refit the new timing chain in exactly the same position as the original chain – the Cam timing links (yellow/gold colour) have 6 vacant links between them (the timing links are 1 and 8). Please also take careful attention when fitting the timing reference link to the crank sprocket. The second yellow/gold link (4 links apart) must be visible through the lower sprocket on the passenger side. Refer pic #3

NOTE #1: There are 33 vacant links between the crankshaft timing link and the Exhaust cam sprocket timing link.

Step 4.

It is strongly recommended that your full timing system is updated at once, not just your chain. We suggest an Atomic #306562 Billet steel/hardened crankshaft sprocket, #306569 Billet chain guide and a #306564 CRMO timing guide pivot be installed at the same time.

Step 5.

Replace the factory TTY (torque to yield) VCT camshaft sprocket bolts with new ones, or alternatively a better quality hi tensile bolt (Atomic #306692 M10/1.5 x 65mm) and torque to 55 ft.lbs (77 NM) with a small amount of Blue Loctite or equivalent on the threads.

Step 6.

Reset the tensioner to the fully withdrawn position and lock in place with a small diameter screwdriver or wire in the retaining arm hole and into the corresponding hole in the body of the tensioner. Refit the tensioner, guides and chain then remove the screwdriver which will then allow the tensioner to push outwards, applying pressure to the timing chain. Rotate the engine several times by hand to ensure the sprockets are correctly timed.

Step 7.

Refit the timing cover and the remainder of engine components. Upon starting the engine for the first time it may take a few minutes for the hydraulic-over mechanical chain tensioner to fully take up the slack in the chain.

NOTE #2: With the latest iteration of our chains we changed from painted timing mark links to yellow/gold zinc passivated plated links.

PIC #4

Remember, if you encounter any problems whatsoever when installing these parts, please contact Atomic direct - we are here to help!