Valve Guides + Valve Seats

Reproductions of the exhaust valve guides as used on IOE models 1921-1929.

Reproductions of the valve guides used on the 45"/750 cc SV engines of the R, W, and G series 1932-1940. Also used on the WR racing engines 1941-1952.

Kibblewhite has researched, tested and chemically separated several cast iron blends, and ultimately specified a combination of ingredients to meet the needs of Harley-Davidson engines. KPM material includes specific amounts of key elements such as carbon, silicon, manganese, nickel, copper and sulfur to create a highly pearlitic structure wit dense fine grains for excellent wear resistance. This "recipe" also allows for a superior surface fnish in the guide bore that is easy on valve stems.

Cast iron valve guides equal to Original Harley guides. The classic iron valve guides feature very good self-lubrication qualities and excellent durability.

Casting a valve seat with the combination of alloys required for today’s fuels is not possible, and only the so-called Powdered Metal Technology facilitates to blend these alloys creating a high density seat with exceptional wear resistance, machinability, and thermal qualities. The KPM valve seats are made from such materials which provide good uniform hardness and resistance to microwelding, wear, and recession. They are compatible with all types of fuel blends, resists corrosion and burning, and are machinable with standard tooling. They have been thoroughly tested on the track and street, in high RPM multi-valve applications, high spring load V-twin applications, with leaded and unleaded gasoline, ethanol and methanol. In each case they have performed flawlessly, making them the seats of choice for cylinder head builders everywhere.

These valve seats for use with unleaded fuels are made from cast iron alloyed with Tungsten, Chrome, Molybdenum and Vanadium in a tool steel base which creates an extremely strong alloy. This gives Rowe valve seats a great wear resistance and better ability to withstand higher temperatures. They can safely operate in excess of 784° Celsius. A special casting process gives greater resistance to oxidation from fuel contaminates, such as sulphur. Extensive tests have shown that Rowe Tungsten valve seats eliminate largely valve and valve seat »pocketing« and recession.
The Rowe seat has an initial hardness of 42 Rockwell (C-scale) that rises to 50 Rockwell (C-scale) during the first break-in miles. The material hardens during this period through heat and valve impact against the seat. This increased hardness greatly reduces seat distortion and extends the life of both the valve and the valve seat. Rowe seats cut cleanly and easily with the same tooling as used for other seats, and can be fitted using the same methods you are familiar with.
The O.D. on all Rowe valve seats is machined with a generous starting radius which allows a precise machining to the desired size. Recommended press fit: Aluminum heads .005”-.007”; cast iron heads .004”-.005”.