Slam Valve Motor, supplying
efficient steam engines for homeowners and professional solar installers
Bringing you the
very latest in 18th century steam engine technology
Slam valve motor info
The slam valve motor is a revolutionary
design of steam engine. The slam valve assembly requires no connections
to the crankshaft, it simply bolts on top of the cylinder. All plumbing
and mechanical connections in or out are contained within the head.
Slam valve heads can be made to be compatible with the pistons and
cylinders from almost any compressor or engine. If a piston has a head
that can be unbolted, a slam valve head can be made to bolt on in its
The valves are timed to produce an expansion cycle within
the cylinder. This improves energy efficiency over non expansion motors
like the James Watt steam engine. For example, from saturated 405
degree F steam to 160 degree F radiator, the slam valve produces 2.5
times the work from the same volume of steam as an idealized non
expansion motor. This gives the example slam valve motor a thermal
efficiency over 20%.
The slam valve motor has a torque control, which works like
the throttle on a gasoline engine but it is not a throttle and gives
constant efficiency. The slam valve head is designed for a long
lifespan. Based on long lifespan compressor technology, it contains no
rotating or linear bearings and requires no lubrication itself. After
thousands of hours of operation, when the piston and cylinder assembly
is worn out, moving the slam valve head to a new identical piston and
cylinder assembly is an easy process often not even requiring
re-plumbing. Solar power generators that run every day may require this
kind of service every five to ten years depending on operating RPM. See
the spreadsheet tool for estimated piston lifespan for any application.
Ported slam valve motors also feature a non expansion mode,
which allows higher power density. Over twice the torque of a gasoline
motor of the same displacement is possible. This allows high power low
RPM operation which leads to longer service life.
this early motor design, torque is controlled by screws on top.
In this later motor design, the flap hinge on top controls