backroom inventors - wemyss
Heat is energy and what an huge amount the motor vehicle throws away with no benefit whatsoever.
Is there perhaps in the future some viable possibility that a designer could use this other than to keep us warm behind the wheel.
A package steam boiler can achieve around 75% efficiency with good maintenance and the rest goes up through the chimney or in radiation losses.
I?m sure someone will know what percentage efficiency a car engine can achieve. and is perhaps even less than this but with modern advances in such things as condensing boilers utilising heat previously wasted up the flue, there just may be some better use than pushing it out of the exhaust pipe.


backroom inventors - Sooty Tailpipes
The Otto cycle requires the creation of heat to give propulsion, and there is no use for the heat left over after doing the work of pushing the piston down. Redirecting this heat back to the intake would reduce efficiency further.

Manufacturers and R&D companies are experimenting with ceramic insulation of bores, foam insulation of the block etc.... Ideally they can make an engine where there is no heat sink effect, and the heat created by the combustion is used more for propulsion, and less dissipation into the block and cooling system.
backroom inventors - L'escargot
.... and less
dissipation into the ........ cooling system.


Now that winter is upon us I'm very grateful for the heat that goes into my car's cooling (and hence heating) system!
--
L'escargot by name, but not by nature.
backroom inventors - Cardew
Car engines typically have an efficiency of 20%. Most of the losses are thermal and the rest are internal - friction etc. Even less power, in percentage terms, gets to the wheels.

Big slow revving maritime diesel engines are the most efficient internal combustion engines getting up to 50%. By that I mean working engines as opposed to experimental engines using special fuels etc.

There have always been masses of research laboratories working to improve the efficiency of internal combustion engines but generally improvements only come in small increments.
backroom inventors - Thommo
Did I not read somewhere that advances in effciency were being made with lean burn technology but that these were all scuppered when government pushed through legislation on catayltic converters because lean burn and cats are incompatible?
backroom inventors - No Do$h
Not incompatible, but the additional displacement required to have lean-burn and a cat for the same output as Cat only makes them less viable. Look at the early Carina E as a classic example. Underpowered from the word go, but with a fine lean-burn unit if not choked and remapped for a Cat.
backroom inventors - Onetap
"Did I not read somewhere that advances in effciency were being made with lean burn technology but that these were all scuppered when government pushed through legislation on catayltic converters"

True. I think Rover were developing/had developed a lean burn engine before the Germans took over the company. I saw Margaret Thatcher (a former industrial chemist) ranting about this in some documentary, the only time the woman said anything sensible.
 

Value my car