New Hope for Steam Power: Extra Exhausting

I personally cannot believe that you will ever get any worthwhile "efficiency" with such a motor you describe....

I personally believe that you will be doing well to even achieve 1% efficiency...... If you pay nothing for your fuel, it could be interesting, otherwise.......

Quoting from Wikipedia at:-

http://en.wikipedia.org/wiki/Steam_engine#Efficiency

In practice, a steam engine exhausting the steam to atmosphere will typically have an efficiency (including the boiler) in the range of 1% to 10%, but with the addition of a condenser and multiple expansion, it may be greatly improved to 25% or better.

A megawatt electrical power station with steam reheat, economizer etc. will achieve up to 50% thermal efficiency.^[16]

It is also possible to capture the waste heat using cogeneration in which the waste heat is used for heating a lower boiling point working fluid or as a heat source for district heating via saturated low pressure steam. By this means it is possible to use as much as 85-90% of the input energy.

That is true, but I think that quote is referring to a traditional counter-flow engine like you would see on a steam locomotive (no exhaust ports in the cylinder wall other than those controlled by a valve). In that case, you would need triple expansion and a condenser to get the most out of the steam expansion. The advantage of a uniflow engine is that it can maximize the available efficiency in a single step, which greatly reduces mechanical complexity and drag. I ran tests on the prototype that I built (and described earlier in this series), and found the total efficiency to lie around 8%. I measured its efficiency with an electric motor hooked up to a resistive load and ran it on compressed air , and compared it to the input energy. I then multiplied that figure by the theoretical Carnot efficiency at that pressure to obtain the numbers. That engine was incredibly inefficienct and leaky, plus the valve timing was so long that it never actually closed during the downstroke stroke to allow for expansion (it was still partially open when the cylinder ports opened, and made a loud "popping" exhaust note). I am hoping that the new engines work better.

I'll believe it when I see it.......

The type of steam engine you are proposing is on many children's steam toys of the last 100 years.....

I even had a friend build a 4 cylinder one just to show that he could, it was then self starting, which yours will not be if I understood you fully, unless it is luckily at the right position when the steam first arrives!!

To self start "most" of the time, you either need more cylinders, or the steam must be valved to push the piston from each side.....

The nice thing about using a motorcycle engine is that it already has a kick-starter built into the transmission. Self starting is really only necessary when the drive train is directly linked to the wheel, but with a clutch to disengage it is unnecessary.

Everyone needs a hobby......