Piston Crowns

At YAF Engineering, we provide full-service inspection and reconditioning of piston crowns and skirts, restoring them to OEM specifications and extending their operational lifespan under high thermal and mechanical loads.

Typical issues encountered include:

Excessive wear of piston grooves
Thermal cracks on the combustion surface
Cracking or peeling of the chrome layer

Inspection process:

Upon arrival, piston crowns undergo chemical cleaning and shot blasting before a detailed inspection is carried out, including:

Dimensional measurements and visual examination
Chrome layer thickness verification using leptoscope
Dye penetrant testing for crack detection
Preparation of a technical report outlining the required reconditioning steps

Standard piston crown reconditioning procedure:

Pre-machining of grooves and crown diameter
Submerged arc welding to rebuild piston grooves and crown to oversize dimensions
Annealing in a digitally controlled furnace to relieve internal stresses
CNC machining for final groove shaping and chrome plating preparation
Hard chrome plating of grooves with 0.5 mm per side thickness
Precision grinding of grooves using specialized equipment to ensure parallelism and dimensional accuracy

In addition, we offer Inconel cladding on the top surface for enhanced protection against thermal fatigue and wear.

Piston skirt reconditioning:

After inspection, worn copper bands are replaced with new ones and machined back to standard dimensions.

All reconditioning operations are performed in-house, utilizing automated welding systems, preheating, annealing furnaces, and precision chrome plating and grinding machines to deliver consistent and reliable results.