The Ahaus Valve Stem Seal Tester measures how much oil flows past a valve seal. Seals are tested under pressure and vacuum at engine operating temperatures and at various speeds.

The job of a valve stem seal is very crucial in the operation of today’s late-model engines. These seals function more like a metered orifice than an actual seal, designed to leak a small amount to lubricate the valve stem and valve guide. It’s a balancing act, too much oil flow past the valve seal, and the engine consumes oil, too little oil flow, the valve guides burn.

When JASPER studies the valve stem seals for a specific engine, an Ahaus Valve Stem Seal Tester is used to measure how much oil flows past a valve seal. Seals are tested under pressure and vacuum. “We run our seal test at engine operating temperatures, and vary the speed of the machine as well,” said JASPER Product Design Engineer Noah Fritchley. “For naturally aspirated engines, we test intake seals under vacuum and exhaust seals under pressure. For seals that get installed on both sides, we test them under both vacuum and pressure.”

This results in using valve stem seals that are of the highest quality for our customers. “Not only high quality but also meets the proper oil flow for that specific application,” Fritchley said. “We use this machine for all of our first article valve seal and quality inspections. This machine ultimately helps us hold our suppliers accountable for producing quality seals.”