Precision Surface Finishing for High-Performance Racing Valves
Since 1986, Motor Parts S.A., a member of the Basso Group, has engineered high-performance valves and springs for competition engines, aeronautics, and extreme-use applications such as multi-fuel and oil-industry systems. Headquartered in Argentina with two industrial plants and over 300 team members, they supply world-class components to motorsport teams across five continents—from Formula 3 Europe, Le Mans LMP2, and World Rally Car, to NHRA Pro Stock, Superbike, and even Jet Ski Racing.
The Challenge: Elevating Surface Performance Beyond Grinding
While Motor Parts is highly experienced in cylindrical grinding, they saw an opportunity to push performance further by refining surface roughness metrics on their titanium racing engine valve stems. In particular, Ra (average roughness) measures the overall peaks and valleys that affect friction, flow, and sealing, while Rpk (reduced peak height) captures the sharpest peaks most likely to wear during break-in. Both are critical in the automotive industry for qualifying parts against the toughest standards — ensuring components deliver maximum reliability under the extreme demands of competition engines.
To achieve these targets, Motor Parts partnered with Bel Air Finishing to develop a high-energy superpolishing solution that was both repeatable and scalable for production.
Hands-On Collaboration in the U.S.
A Motor Parts team member traveled from Argentina to Bel Air’s lab in Rhode Island, where they reviewed sample results, polishing strategies, and equipment options in collaboration with Bel Air’s engineers. This visit helped align on process direction and validate potential finishing technologies.
The Results: Superpolished & Ready for the Demands of Motorsport
Working closely with Bel Air’s applications team, Motor Parts transformed their titanium valve stems from a rough-ground state to an ultra-polished finish. The original samples averaged 4.25 µin Ra, while initial polishing trials reduced this to 1.90 µin Ra. After refining the process, Bel Air achieved an ultra-smooth 0.73 µin Ra — an 80% reduction in roughness.
This performance was made possible through centrifugal barrel finishing, a high-energy mass finishing method where multiple barrels rotate in opposing directions to generate intense, controlled force between media and parts. Unlike low-energy processes such as vibratory finishing, centrifugal barrel systems achieve rapid material removal and fine surface refinement, making them ideal for demanding applications like titanium valves.
The process was further enhanced by the AutoHone™ Robotic Reverse Drag Finisher, which adds programmable precision and repeatability. This combination of high-energy batch processing and robotic control gave Motor Parts the flexibility to scale production while maintaining exacting quality standards.
Whether it’s drag racing, oval track, motorcycle, off-road, or even aerospace, Motor Parts components operate in some of the most demanding environments on the planet. Bel Air is proud to support that performance with finishing solutions that meet — and exceed — expectations on the world stage.
👉 See full surface roughness results and process details »
Looking to maximize valve performance? Send us your part for a free surface metrology evaluation or speak with our applications team to explore custom polishing solutions