Show Notes
Todd, Will, and Myer are back for round two on camshafts, picking up right where they left off and going even deeper into diesel cam theory. If you got something out of the last episode, this one takes it further with real numbers, real data, and some genuinely nerdy breakdowns that most Dodge Cummins guys never get access to.
This episode is built around volumetric efficiency and how race engines actually push past 100 percent. The crew explains scavenging, low pressure zones, and how intake air speed changes everything about when you should close that intake valve. They break down piston speed and rod angle, why 70 degrees after top dead center is the sweet spot for airflow, and why valve lift speed is limited by lifter size, which is a big reason Cummins runs such a massive lifter compared to the gas world.
From there Will pulls out actual cam data measured off real factory camshafts using a cam doctor tool, comparing intake and exhaust duration and valve timing across every generation of Cummins, first gen, 12 valve, VP44, and common rail. The differences in exhaust valve opening timing alone explain a lot about why certain Cummins generations start easier, burn cleaner, or make power differently. They also dig into intake and exhaust centerline angles and why lifting the valve higher instead of just chasing bigger duration numbers is often free horsepower with no downside.
The back half covers valve springs, coil bind, and why some aftermarket cams cause problems with stock components, plus a preview of a project cam being custom built for an upcoming race truck this September, designed specifically around a narrow RPM window instead of chasing bigger numbers across the board.
If part one gave you the foundation, this episode is where it gets real. Whether you are running a first gen, a 12 valve Dodge Cummins, a VP44, or a common rail, this breakdown gives you a real foundation on how factory and aftermarket camshafts are actually engineered.
Subscribe on YouTube and follow the podcast on your platform of choice so you catch the rest of this camshaft series as it drops.
Colt Cams are now part of the Power Driven lineup, so if you want to dig deeper into the camshafts covered in this episode or see what fits your Cummins, head over to PowerDriven.com to check out the full selection.
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