Exhaust Parts for Willys M38
Exhaust Manifold, Manifold Gaskets and Heat Riser Valve for Reliable Exhaust Flow (1950–1952).
Why the Exhaust System on the Willys M38 Wears Out Over the Years.
The exhaust system of the Willys M38 is one of the often-underestimated wear areas on this rugged post-war military vehicle. The 4-134 L-Head "Go Devil" engine relies on a functioning heat riser valve in the exhaust manifold, controlled by a bimetal spring, to preheat the intake air in cold conditions. Over time this spring loses tension, the valve sticks or no longer opens fully, resulting in noticeably poorer cold-start behavior. The exhaust manifold itself is exposed to constant temperature cycling and can develop cracks or corrosion. The gaskets between manifold, cylinder head, and exhaust pipe harden, lose elasticity, and start leaking, leading to hissing noises and a noticeable loss of power. Anyone who regularly drives or is restoring their M38 should inspect the complete exhaust system at regular intervals.
- Exhaust Manifold: The exhaust manifold for the 4-134 L-Head engine safely routes exhaust gases from the cylinder head.
- Manifold Gasket Set: The 3-piece manifold gasket set reliably seals the intake and exhaust manifolds.
- Exhaust-to-Manifold Gasket: The exhaust-to-manifold gasket between the manifold and exhaust pipe prevents annoying hissing sounds.
- Heat Riser Repair Kit: The heat riser repair kit ensures reliable cold-start performance.
- Bimetal Spring: The bimetal spring precisely controls the heat riser valve based on engine temperature.
American Brand Expertise for Your Willys M38.
The exhaust manifold, bimetal spring, and heat riser repair kit are supplied by Omix – American parts expertise for classic Jeep and Willys models. The manifold gasket set and exhaust-to-manifold gasket come from Crown Automotive, also a US manufacturer with long-standing experience in classic military and off-road vehicles.
Your Partner for the Willys M38 Exhaust System.
Whether you need a single gasket or a complete exhaust system overhaul, we're happy to advise you on installation order, torque specs, and compatibility with other L-Head models like the CJ2A, CJ3A, or Ford GPW. Your order ships from our warehouse as fast as possible, so you can keep wrenching without delay.