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Autopapyrus · Iveco Stralis 7.8 Cursor 8 F2B (2009)
https://autopapyrus.com/guides/iveco/stralis/valve-lash-adjustment/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Iveco Stralis 7.8 Cursor 8 F2B (2009): Valve Lash Adjustment

The Cursor 8 (F2B) is an inline six with two valves per cylinder and an overhead camshaft. It uses a rocker arm valve train, so "selecting shims or tappets" does not apply here. The lash is set with the screw on the rocker arm. Adjustment follows the "sum of 9" scheme: two cylinders at a time are in the right phase. Take the exact intake and exhaust lash values and the locknut torques from the manufacturer's manual for your version (Euro 3, 4 and 5 engines can differ, including whether they have an engine brake/retarder).

Difficulty: Hard Time: 3-5 hours Steps: 12 Tools: open-end and ratchet wrench set, torque wrench, feeler gauge set, crankshaft turning tool (or a tool that works through the starter opening/flywheel housing), flywheel/crankshaft position locking pin, dial indicator, screwdriver, marker, new valve cover gaskets.

Part

  • 🔩 Valve cover gasket set (one per cylinder) and plug/injector well seals as needed. Shims and tappets are not required for this adjustment: Cursor 8 engines use a rocker arm valve train, and the lash is set with an adjusting screw and locknut

Step by step

12 steps
  1. The engine must be cold: oil and coolant temperature no higher than 30-40 °C. Shut off the engine, disconnect the battery ground, set the parking brake and chock the wheels. Tilt the cab and make sure it is securely locked in place.
  2. Remove the accessible components from the engine: air ducts, crankcase ventilation hoses and any wiring harnesses in the way. Wipe down the cylinder head cover so dirt does not get inside. Remove the valve cover bolts, then remove the cover and gasket. Set the injector harness aside carefully: on an engine with electronically controlled unit injectors, work carefully and do not damage the wires.
  3. Prepare to turn the crankshaft: install the turning tool on the flywheel or on the power take-off at the front end of the crankshaft. Turn the crankshaft only in the direction of engine rotation. Use the flywheel locking pin to determine TDC of cylinder 1 accurately.
  4. Bring the piston of cylinder 1 to TDC on the compression stroke. Indication: both valves of cylinder 1 are closed and have lash, and the valves of cylinder 6 are in the overlap position (exhaust closing, intake opening). The locking pin should enter the hole in the flywheel. If the rocker arms of cylinder 1 are pressed down at this point, turn the crankshaft one more full revolution.
  5. Adjust the valves using the "sum of 9" scheme relative to the firing order 1-5-3-6-2-4. With "piston 1 at TDC compression," adjust the valves where the cylinder number plus the number of the neighboring cylinder in overlap gives 7. If the manual describes the scheme differently, follow the manual. A practical check: the valves considered adjusted are those that are currently closed and sitting on the base circle of the cam, and you do not touch the valves of the cylinder in overlap.
  6. Measure the lash with a feeler gauge between the rocker arm and the valve bridge or valve (per the manual's diagram). If the lash does not match the value for your version, loosen the locknut on the adjusting screw, turn the screw until the feeler gauge of the required thickness drags lightly, hold the screw with a screwdriver and tighten the locknut. After tightening, check the lash again: the locknut often shifts the adjustment.
  7. Check that the feeler gauge slides through with light drag and does not bind. Mark the checked valves with a marker so you do not miss any.
  8. Remove the locking pin, turn the crankshaft 360° and bring it to TDC again for the next cylinder in the scheme. Repeat for the remaining valves until you have gone through all 12.
  9. If the engine has an engine brake (EVB), it has its own lash on the additional rocker arms or brake pistons. Adjust it separately using the values from the manual. Do not confuse it with the lash of the main valves.
  10. Do not touch the unit injector rocker arm adjustment (if your version has them) without the manual: it is not a lash but a preload, set with a torque wrench, and an inaccurate setting can damage the injectors or the camshaft.
  11. Clean the mating surfaces of the head and the cover, install a new gasket and tighten the valve cover bolts in a crisscross pattern in two or three passes. The torque is low, about 8-12 N·m (6-9 lb-ft) (exact value per the manual).
  12. Reconnect the crankcase ventilation and the harnesses, then reconnect the battery. Start the engine, warm it up and make sure there are no oil leaks and no valve noise. Lower the cab and check that it is locked.

Common mistakes and warnings

  • Check the exact intake and exhaust lash values, the locknut torques and the adjustment scheme for your version of the Cursor 8 against the manufacturer's manual: they depend on the emissions class and equipment. Do not adjust the valves on a hot engine. The lash will come out too small, which leads to burned valves. If you have no experience with rocker arm valve trains and unit injectors, leave the job to a truck repair shop.