The inlet valve is critical for top performance and minimal oil consumption. When valve stems and valve guides become worn, the resulting excessive clearance can result in poor valve sealing and oil consumption.
This inlet valve is applicable for Norton 750 and 850 Commandos from 1968-1975.
The Kibblewhite Black Diamond inlet valve features a wear resistant finish that prolongs service life of the valve. The head diameter is 1.5″, stem diameter .3107″, and 4.065″ length. Manufactured to exacting standards in the USA.
The valve stem and valve guide clearance is critical, as well as the valve face and valve seat interface. Valve springs must also be in serviceable condition to properly close the valve and maintain an adequate seal with the valve seat.
The cylinder requires removal to service the valvetrain. Once the head is removed, a valve spring compressor is employed to disassemble each valve assembly. Valve seats require lapping-in of the new valves, at a minimum, and may require cutting to gain an acceptable seal with the valve.
All KPMI black diamond™ stainless steel valves are impregnated by a special German process to a depth of .002”, with a surface build up of .0002”. This “Black Diamond™” process improves wear properties, reduces friction, and provides resistance to corrosion and wear that is superior to chrome and nickel electrolysis plating. Each valve is designed using finite element analysis software, and profiles are tested on our computerized flow bench. Black Diamond™ valves are light, strong, one piece forgings with profiles that provide excellent flow characteristics.
Head diameter: 1.500″ stem diameter .3107″ tulip 1.5″ radius overall length 4.065″