The valve is a simple variable-geometry device that controls the opening and closing of the specified flow window or valve curtain area as determined by the camshaft and rocker ratio. The valve curtain area is defined as the flow window created by the open valve at maximum valve lift.
CALIFORNIA LEGENDS The California Gold Rush In the cold morning hours of January 24, 1848, James Marshall, a construction foreman at Sutter s Mill, was inspecting the water flow through the mill s tail race.
The first discovery of gold, at Rancho San Francisco in the mountains north of present-day Los Angeles, had been in 1842, six years before Marshall's discovery, while California was still part of Mexico.