Terry K wrote:
dazed and confuzzed wrote:

Terry K wrote:


Fuel efficiency?
The hot exhaust from the primary / combustion cylinder would go into
the expansion stroke of the larger secondary cylinder,

snip

"Modern" i.c. engines lose much of the fuel energy in hot exhaust and
water cooled blocks, let alone incompletely combusted CO gas. This
energy, if recovered, might save 50% or more of the energy lost, about
33% increase in efficiency.

I cannot see why the same principal would not work in a diesel ignition
engine.

Such an "internal steam engine" could reduce the consumption and price
of fuel. I guess that's why we haven't heard of it.

One difficulty is that an otto cycle (four stroke) only produces
exhaust every second revolution, so the secondary expansion cylinder
might want to be geared 1:2, or it's valve(s) timed to acommodate that
fact, or with an intermediate pressure vessel between the cylinders.
It's exhaust valve would close every second revolution, timed to the
exhaust of the primary exhaust stroke. A two stroke engine would not
need such complication, but it's secondary piston crank angle would be
offset so as to lengthen the primary power stroke to a full 1/2
revolution power / expansion stroke, as opposed to the common 1/4
revolution power stroke.


Alternatively, If two four stroke cylinders were timed and valved so as
to feed only one secondary expansion cylinder which injected water to
expand and cool the exhaust gas, etc, then the power output stroke of
such a three cyliner engine would be 360 degrees in total as opposed
to two, one quarter revolution power strokes. Two such engines
connected together for balance and timed right might show very good
torque figures at near stall speed, like steam engines do. It would
also balance well.



The only issue that I see for your idea is that the engine you propose
would be fairly heavy for it's power output, and would be best operated
at significantly slower speeds than current gasoline and diesel engines
normally operate at. Even diesels (modern ones) operate at around
1500-2000 rpm. Yours would be happiest closer to 500 RPM.


Thank you for your assistance. I don't see why, really. See the
addendum above. It might work out, y'know.

Most cars never need all the potential power they lug around, and every
pound of engine and fuel saved, is a pound that does not sap the
delta-vee.


Another huge saving in fuel efficiency could be promoted at home, a
reversible air conditioner / heater might get used more to heat than to
cool over the course of a year, saving considerable heating fuel cost,
if mainly only during the spring and fall.. Why have we not heard of
it?



--
"TAANSTAFL"



I don't recognize that acronym.

Terry K

There
Ain't
No
Such
Thing
As
A
Free
Lunch

--
“TAANSTAFL”
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"A prudent man foresees the difficulties ahead and prepares for them;
The simpleton goes blindly on and suffers the consequences." - Proverbs 22:3
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