Dick Raczuk was curious. He asked well-known engine builders why, even with computer-controlled machining capable of cutting valve faces and valve seats to precise dimensions, they were still hand lapping the valves.

“So they don’t leak,” he was told.

Raczuk is familiar with leaks from his experience inventing specialized tools that help car builders mate various types of hoses with AN and push-lock fittings. Now the owner of Koul Tools, he has found another type of plumbing that needs attention: flared ends on hard lines, a problem he encountered restoring a V12 Packard.

“Even with the best flaring tools,” says Raczuk, “a small percentage will end up leaking because of irregularities.”

Raczuk then developed a finishing tool called the Surseat P51 line lapper. Constructed from aluminum, the tool is simple in its design but brilliant in its results. The flared tube end is securely held in a steel collet, then the user applies pressure and twists a diamond-dust-coated head cone into the flare to remove any imperfection in the surface or the tube edges.

Koul Tools offers both 37- and 45-degree heads along with five different sized collets to cover most popular automotive needs using tubes from 3/16-inch up to ½-inch diameter.

Raczuk says the tool can be used for both preventative and repair.

“Just keep it in the tool box for whenever you need it,” he says.

The tool comes in a handy carrying case. Coming in the near future will be a male version that cleans up the fitting surface.