Jeep 4.0 Engines: How to Rebuild and Modify

The venerable Jeep 4.0L in-line 6 engine has powered millions of Jeeps, including CJs, Wranglers, Cherokees, and Wagoneers. The 4.0 delivers adequate horsepower from the factory, but many off-road drivers want more horsepower and torque to conquer challenging terrain, which means these engines are often built and modified. The Jeep 4.0, or 242-ci, is affordable, abundant, exceptionally durable, and many consider it one of the best 4×4 off-road engines.

In this Workbench title, veteran author and Chrysler/Jeep engine expert Larry Shepard covers the rebuild of an entire engine in exceptional detail. He also delves into popular high-performance modifications and build-ups. Step-by-step photos and captions cover each crucial step of the engine disassembly. He shows the inspection of all critical parts, including block, heads, rotating assembly, intake, and exhaust. Critical machining processes are covered, including decking the block, line boring, and overboring the block. The book provides exceptional detail during the step-by-step assembly so your engine is strong and reliable. Installing a larger-displacement rotating assembly (or stroker package) is one of the most cost-effective ways to increase performance, and the author covers a stroker package installation in detail.

With millions of Jeep 4.0 engines in the marketplace (which are subjected to extreme use), many of these engines require a rebuild. In addition, many owners want to extract more torque and horsepower from their 4.0 engines so these engine are also modified. Until now, there has not been a complete and authoritative guide that covers the engine rebuild and build-up process from beginning to end. Jeep 4.0 Engines is the essential guide for an at-home mechanic to perform a professional-caliber rebuild or a high-performance build-up.