Slam Valve Motor, supplying efficient steam engines for homeowners and professional solar installers
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             The highest torque car engine on earth.  Brought to you by the reincarnation of Abner Dobie.

Plug hybrid vehicles

A hybrid vehicle is a vehicle with two different types of power plant working together to give performance which better than either power system could provide individually.  The hybrids available today are gasoline engines working in parallel with an electric motor/generator/battery system.  The smaller gasoline engine gives better efficiency, the electric system provides additional acceleration to simulate the performance of a larger engine.  Most of the hybrids available today feature regenerative braking.  Regenerative braking uses the generator to store energy in the battery when decelerating.  This is energy which would otherwise have been wasted in the brakes.  Use of regenerative braking reduces the energy needs of the vehicle and improves efficiency in situations where braking is used often such as city driving.  Some hybrids can be modified to allow the battery pack to be plugged in to charge as opposed to only charging from the gasoline engine.  This is called a 'plug hybrid', and it allows the user to achieve very low or zero fuel consumption for short trips while still allowing long trips at normal fuel consumption.

Steam powered vehicles are not a true hybrid, they just do what a hybrid does.  In the steam powered vehicle, there is only one power plant to drive the vehicle.  This power plant has four modes of operation.  The first is a low torque high efficiency mode.  The second is a moderate torque moderate efficiency mode.  The third is a very high torque low efficiency mode.  The fourth is a negative torque mode used for regenerative braking.  Modes two and three are enabled by porting the motor,  see the page on ported motors.  Mode 4 is a special feature of the slam valve head which will add some complexity and therefore cost to the head.  The accelerator has control authority over the vehicle in modes 1,2, and 4.  In the highest torque mode (3) the accelerator will not affect the torque since the motor is maxed out.  Backing off on the accelerator from mode 3 causes the motor to drop to mode 2 then 1, which allows control over torque.

Steam powered vehicles can run from any source of heat.  One popular source of heat is to combust gasoline and air.  Gasoline is available everywhere and if a catalytic combustor is used the vehicle will produce very low nitrous oxides which are a key pollutant.  Gasoline fired boilers provide an option for very long range.  Another source of heat is a thermal battery.  A thermal battery stores heat.  The battery is charged by plugging in a heating element within the battery while the vehicle is parked.  The energy density of the thermal battery makes a range on electricity of up to 100 miles practical.  The current thermal battery design stores 250 usable watt hours per kilogram and uses no exotic, toxic, or expensive materials.  Lithium ion batteries currently store around 120 watt hours per kilogram depending on which type, and are filled with toxic and dangerous materials.

By paralleling the two sources of heat,  we achieve the effect of a plug hybrid vehicle.  The vehicle can run entirely on electricity for short trips.  The vehicle can run on a mix of electricity and gasoline for long trips.  The vehicle can feature regenerative braking to improve efficiency in city driving.  It is going to create some language issues since its single power plant is not truly a hybrid, and its one cell battery is not truly a battery.  However we have to use words that we know.

The conversion from a gasoline powered vehicle to steam requires some labor but is straightforward.  For ported motors the engine must usually be pulled from the car.  The cylinder block is removed and re machined, then reinstalled.  The gasoline head with its valves and manifolds is discarded.  Much of the equipment under the hood may be discarded.  A slam valve head machined for this particular engine is installed on top of the cylinder block.  A gasoline fired boiler is installed on top of the engine.  The engine is insulated thermally.  Waste steam is plumbed to the existing radiator, supplemental radiators may be added to improve efficiency.  The throttle cable is routed to the slam valve head(s).  In the center to rear of the vehicle as low as possible while being isolated from the passenger compartment, a thermal battery is mounted if desired.  An insulated heat pipe leads energy from the battery to the slam valve head.  Water pump, vacuum pump, water and oil reservoir are mounted under the hood.

efficiency graph
This efficiency applies to ported motors as well at low torque
ported power graph
Ported motors feature extremely high peak torque
unported power graph
This is the power to stay below to get optimal efficiency.
converted gasoline generator
This gasoline powered generator was converted to a ported steam motor