Stewart

Stewart Components: Decades of High-Performance Cooling Expertise

Stewart Components, headquartered in Tyler, Texas, has spent over 25 years as a recognized leader in high-performance automotive cooling system research and development. Stewart earned its reputation by engineering cooling solutions that go far beyond what stock systems can deliver — from mild street builds all the way to the most demanding professional motorsports environments.

At the heart of the Stewart lineup are their renowned engine water pumps. Rather than simply repackaging OEM designs, Stewart approached the water pump from the ground up. The result of that dedication includes innovations like special high-strength castings, larger internal flow passages, more efficient impellers, and stronger bearings — engineering refinements that add up to significantly improved coolant flow at both idle and high RPM. The tiered Stage 1 through Stage 4 lineup means there is a Stewart pump suited to everything from a mild OEM-style replacement to a full-race application demanding the absolute maximum in cooling capacity.

Complementing their water pumps, Stewart also offers precision-engineered engine coolant thermostats. Co-developed with Robertshaw, these high-flow thermostats feature a balanced-sleeve design specifically built for high-flow, high-RPM applications. Unlike standard thermostats, Stewart's design includes bypass holes machined directly into the poppet valve, allowing the thermostat to function properly even when paired with an aggressive high-flow water pump — a pairing that standard thermostats simply cannot support.

The broader water pump & components category rounds out the Stewart catalog, offering the supporting hardware and accessories needed to build a complete, properly matched high-performance cooling system. Whether you are assembling a show-quality street rod or prepping a race engine, having the right complementary components ensures the entire cooling system works as an integrated unit.

In 2001, Stewart Components was acquired by Engineered Machined Products (EMP), North America's leading supplier of cooling pumps in the diesel industry. This partnership brought advanced manufacturing capabilities and engineering resources to Stewart's already proven designs, furthering their ability to push the boundaries of high-performance cooling technology.

Why Choose Stewart Components?

• Over 25 years of focused high-performance cooling system R&D
• Tiered water pump lineup (Stage 1–4) to match any performance level
• Race-proven designs trusted by professional engine builders and race teams
• High-flow thermostats engineered to work in tandem with performance water pumps
• Backed by EMP's world-class manufacturing and engineering resources