Water/fuel emulsions (which is what this is) do indeed work. They use the same increased gas expansion principle, and can also reduce emissions of nitrogen oxides and in some cases, particulate matter. In some cases the reductions are quite significant (40% or more for NOx). Vendors often oversell what their products are capable of doing, though. I recall seeing one claim that the product improved operating efficiency because it “burned” the water and extracted heat from it, which is complete nonsense.
Sorry. I don’t know how to be any more clear. “Dragging” a piston downward requires essentially zero effort, and thus exerts virtually zero force on the crank (and associated parts). Compression stroke (piston traveling up) is working to achieve a, say, 10 to 1 compression ratio, so the resistance is 10 atmospheres. This is about 150 pounds per square inch pressure. Your home air conditioner operates in this range. The compressor at the gas station that fills your tires produces about this much pressure. No massive metalic machinery is needed to contain pressures of this order.
An explosive power stroke is just that-- explosive. I can’t find a cite just now giving typical internal pressures of an IC cylinder during power stroke, but pressure is directly proportional to temperature. The temperature of the exploding gas is thousands of degrees. Thus the pressure will be thousands of times higher than in an inert cylinder. It is high enough to smoke the tires on your car and send you and a couple thousand pounds of dead weight zipping down the race track. Engines are massive because they must contain these pressures. Crank shafts and associated parts must be able to handle these huge forces.
Again, having a single “bad” cylinder (producing less power than the others) will produce enough engine noise to send you to the repair shop. The “bad” cylinder is trying to spin the cank at a different speed than the other cylinders, at the same time. Ignoring this and continuing to operate the engine will cause major internal damage from the unbalanced but enormous forces involved.
I’d love to be proven wrong by seeing that 6 cycle guy scale up his prototype to multi-cylinders. But I just don’t think it’s gonna work. Not in a reciprocating engine.
What does work is to capture the waste heat to produce steam, and then use that steam to drive a separate engine, especially a turbine. Then mechanically connect the turbine to deliver its extra power to the drive train. I believe this is what BMW is working to achieve. But, as said up-thread, it makes for huge additional complexity that probably isn’t worth while for an automotive power plant.
I still think that EC by itself, given some R&D to bring it into the 21st century, would have tremendous advantages in today’s world. You could produce a far simpler automobile (especially with a Wankel-type rotary instead of reciprocating piston engine) at much lighter total weight that could burn any available fuel. Got propane? Burn it. Got alcohol? Burn it too. Kerosene, coal oil, even powdered coal (or powdered wheat, for that matter). Heck, you could design the burner box to be an exchangeable component, maybe even simple enough for advanced do-it-yourself. Then, if you run low on propane, you could switch to a burner designed for vegetable oil. Or wooden logs. Or dried cow pies. The boiler doesn’t care what the fire box is doing-- all it needs is a source of heat. Engine power is unaffected, since it is a factor only of boiler pressure, not method of heating the boiler.
Talk about energy independence-- I could run my car for years burning nothing but dried lawn trimmings. Farmers could run their farm equipment entirely on the “chaff” and other waste from their harvests. Bill Gates, are you listening? We need some seed money…
Thanks, CD. In that case it seems to me that we need some electronics, of the order of sophistication of that used for modern engine management, in order to adjust the water spray to match the steam stroke to the IC (assuming this is feasible, that is, that there is enough heat left over that the steam stroke can be as powerful as the IC stroke). We can already detect engine knock and similar, and adjust both ignition timing and fuel mix to keep the engine running optimally. Compared to that, matching steam output to IC output shouldn’t be a killer.
I’d be interested in seeing if this ever sees the light of commercial day, though. I’ve seen many other bright ideas go nowhere - I saw a “stepped piston” two-stroke advocated years ago, but never since even though it would have slashed oil consumption.