Stanley Piston Valve Block - Nergaard's


New Cylinder 20 HP Stanley

This is a piston valve 20 hp Stanley cylinder machined casting.  The design is by Dave Nergaard and he has several for sale.  It is designed to be bolted to an existing Stanley engine with the only modification being to reverse the eccentric drives to the valves because of the piston valves.  Traditional slide valve Stanleys had a weakness in spalling or galling when the oil injector into the steam line did not work or under high steam pressures and high superheat. 

  Dave Nergaard and Tom Kimmel when Tom was visiting him 2013

Dave Nergaard and Tom Kimmel

It was very difficult to get at the valve face through the steam chest opening to machine the face smooth.  Therefore it is much easier to replace the casting with a piston valve design that is both 10 % more efficient and will never spall because there is no side loading of the valve.  A further improvement of this design would have shorter steam passages between the valve and the cylinder heads.

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20hp Stanley piston blocks   20hp Stanley piston blocks

20hp Stanley piston blocks

20hp Stanley piston blocks    

For More Information or availability for purchase, please email:
Littleton, Massachusetts     -     Both machined and unmachined blocks available.