First the piston tops and ring lands are cleaned with a glass bead machine. If you want the whole piston glass beaded, for race motor installation, that service is available too.
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Next the old locator pins are removed in an EDM machine. All the old pin holes are inspected under a microscope for a perfect clean bore.
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A new pin hole is drilled into the crown of the piston in the center of the boost port. The location of the pin is critical. It uses the boost port charge to cool the pin. A new hardened steel pin is pressed into the piston with a 6-ton press. The top of the piston is milled down to accept a weld and to counter sink the new pin.
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The piston is then welded to totally encapsulate the new pin leaving no hole for it to back out. The weld also eliminates the pin being exposed in the combustion chamber. Unfortunately the welder can not be shown due to the fact that it is a custom made device and the secret to the whole operation. It can weld the piston never heating the crown over 120 degrees. Normal welders will warp the piston causing a disaster later. The top of the piston is then milled back to its original shape.
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The milled area is smoothed and the edge of the piston is radiused to help with detonation. The new location of the pin is critical. It is located in the small boost port so the incoming charge can cool the pin. The alignment of the ring gaps does not affect compression in any way.
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All pistons are double-checked and hand fitted with rings before they leave the shop. This ensures you will get back a piston that is ready to run.
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Parker Enduro 1999 Billy Joule #38 John Marles #3
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