2001-2025 Duramax 6.6L Callies Stage 1 Alternate Firing Order Induction Hardened (270-009)

The main reason for modifying the Duramax firing order with the camshaft is to relieve stress on the front portion of the crankshaft in higher performance applications. The OEM firing order ends at Cylinder #3 and then continues from the beginning through cylinders 1 and 2.

The Duramax Cranks see the most strain and tend to break right behind the first rod throw at the intersection of the second main journal (the snout). We have seen failures on anything from mildly modified daily drivers to max effort trucks. The Duramax engine Harmonics become too stressful on the cranks when getting into the higher RPM ranges and bigger power levels with the OEM firing order. With this DuraStar Alternate Firing Camshaft, cylinders 1, 2, and 3 are moved away from each other to distribute the stress of combustion more evenly and help reduce the abuse to your crankshaft.

Duramax engines respond to alternate firing camshafts better than any other diesel on the market. Thanks to the high flow aluminum heads, the right camshaft can increase the Duramax's Head flow considerably. Dyno tests have proven a much broader power curve, increasing HP and Torque through all RPM's making this mod perfect for anything from a daily driver to NHRDA usage.