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 performance ported
Porting a motor means to machine a hole in the side of the cylinder
wall which connects to the radiator. Porting reduces displacement of
the block by 10-20%. Porting allows two additional modes of operation
that allow increased torque. The first mode which provides high
efficiency at lower torque is still available. Unported motors can
stall, ported motors are very difficult to stall. At low RPM, a ported
motor puts out maximum torque and can do so at arbitrarily low speed.
The low speed high torque mode is effectively the same cycle as the
James Watt steam engine.
motors are suitable as automotive power plants. The high
mode provides for rapid acceleration of the vehicle. The lower torque
mode has the efficiency to be competitive with the gasoline engine.
Generally an automobile requires about 20 horsepower on the
average to maintain freeway speeds. See the 'guess my MPG'
spreadsheet to see how much power this is for any given car.
a 2 liter motor running at 2000 RPM, the maximum efficiency is met at
24 horsepower or below with 350 deg F boiler and no vacuum pump,
or 37 horsepower or below with a 450 deg F boiler.
power at 2000 rpm (at lower efficiency) is 80 horsepower at 350 deg F
boiler, or 260 horsepower at 450 deg F boiler. Compare to a
gasoline engine which produces only 40 peak horsepower at 2000 RPM.
and unported slam valve motors feature a smooth accelerator control
which has no time lag from actuating it to change in torque out.
The accelerator is a simple mechanical linkage on each
easily tied to the throttle cable from a vehicle. Unlike the
gasoline engine, the slam valve motor efficiency does not drop as the
accelerator is changed. There is a wide range of torque and
over which the motor will achieve its maximum efficiency.
Reducing torque reduces the steam consumption of the motor
applies to ported motors as well at low torque
feature extremely high peak torque
This is the power
to stay below to get optimal
This gasoline powered generator was converted to a ported