Chunky Charley™ ISX Valve Camshaft

MMWX.4298626 | For All Cummins ISX DOHC Engines

Thicker Lobes. Bigger Attitude. That's Chunky Charley.

The Momentum Worx Chunky Charley™ ISX Valve Camshaft is based on the legendary Cummins 4298626 valve camshaft, a popular upgrade for Cummins ISX performance builds.

What makes Chunky Charley different from a "regular" cam?

20mm lobes instead of the standard 18.5mm lobes.

That makes it an ideal choice for drivers running a non-VGT turbo setup who are looking to regain some of the stopping power lost when the factory VGT turbocharger is removed.

Features

• 20mm valve lobes
• Based on the proven Cummins 4298626 camshaft
• Fits Cummins ISX DOHC engines
• Compatible with CM870 and CM871 applications
• Popular upgrade for non-VGT and T6 conversion trucks
• Helps improve engine brake effectiveness on fixed-geometry turbo setups

Why Chunky Charley?

Because "Moderately Increased Valve Lift Performance Camshaft" doesn't fit on a T-shirt.

One of the biggest drawbacks of converting an ISX to a fixed-geometry turbocharger is reduced engine brake performance. The factory VGT creates exhaust backpressure that helps the engine brake do its job. Once the VGT is removed, much of that braking assistance disappears.

Chunky Charley helps fight back.

By utilizing wider 20mm lobes, Chunky Charley increases valve lift compared to the standard 18.5mm design, helping the engine brake work more effectively on non-VGT applications. While it won't completely replace the braking characteristics of a VGT-equipped truck, it can help recover valuable braking performance that would otherwise be lost.

For CM870 and CM871 owners running large-frame turbos, T6 conversions, and other non-VGT configurations, Chunky Charley has become the go-to camshaft for getting some of that lost stopping power back.

20mm of pure valve-lifting authority.

Chunky. Charley. Approved.