From the BWO "Pin Me; Pay Me" files: The hydraulic replacement for internal combustion engines.

Presented for you perusal, a cut-away of the notoriously inefficient Wankel/Rotary Engine.

I think again today of my "water engine" which uses(so far) an oil based medium for which to generate hydraulic force, which, by virtue of the engine, transferred into rotational force or "torque".

As I envision it, there is an intake and exhaust stroke, just like a conventional gasoline or diesel engine, however, the stroke generally just either builds pressure on intake, or relieves pressure on exhaust.

In a two-cylinder configuration, we have a simple elbow intake, like so, leading between the cylinders:

So far, what is conceived is a sort of "non-throttled" version that runs at constant RPM, and might be used as a power multiplier for something like either a smaller gasoline engine, or even an electric motor.

There are also other unknowns, such as at what PSI internal pressure becomes explosive, how to control that pressure(safety valves), and of course, throttling.  So then we have a kind of "perpetual generator" engine that runs at a low operating temperature and needs no added fuel.

Also thinking of a kind of single-cylinder mock-up with kind of a master power cylinder, and a slave cylinder relief tank.  I think of home well water setups on the slave cylinder, an actual tank with a rubber bladder that helps to regulate pressure, but there could be something of a boot or actuator that is applied to that bladder to alter pressure, basically just push the bladder around alternately increasing or decreasing fluid pressure with the medium.

The backstory:  So I was about 10 years old, having seen movies like Dawn of the Dead 1978 and the Stand tv miniseries, daydream about "what if there were no other people?".  I would have a cool car, I thought, with flame graphics on the side.  But I thought further, no power, no fuel supply: how could I get gas for a car?

They say if you want a problem solved, bring it to a child, because they see things so simply, without a lot of the mortifying constructs that adults get taught.  Simply, "ask a child", and you get an unfettered no BS response without any of the clotting or contradiction of common sense or a liberal arts education.