"DSK" wrote in message
.. .
If you couple a diesel to a generator, so it can constantly run at it's
most efficient RPM & throttle setting, then use the electricity to drive
the car, you basically have a locomotive only with tires for road use.
Adding tricks like high-density permanent magnet motors (or the
still-expesnive cobalt motors) & advanced tech battery banks &
regenerative braking & solar panels & bulk/trickle chargers boosts the
efficienct higher yet, but basically it's still a constant-load diesel
with an electric transmission.


Shortwave Sportfishing wrote:
what he said.

Thanks Tom- while I was pontificating (stop me if you've heard this
before) I forgot to add a few details about why it makes particular sense
for cars right now.

The basic technology is the most efficent load-mover devised and has
origins before WW1. Battleships & trains have used such plants, and as
advances in diesel engine design (along with metallurgy & casting) allow
us to make diesel engines that are both MUCH bigger and much smaller than
were practical just a few years ago.

AFAIK all big commercial ships, tankers & the like, have big-ass diesel
plants (direct drive, no reduction gear) now. Small diesels have made
similar... or even greater... advances. Small diesel generators are almost
magic!

It's possible that somebody will be able to make something along the lines
of a carbon fiber Wankel that will get more muscle from a gallon of fuel,
but I'm betting it will be a fair bit of time from now, by which time fuel
cells will probably be the workaday power source.

DSK


As the wankel engineer told my class in university, that the Wankel is great
if you have no pollution controls. Is basically a dirty engine.

Calif Bill wrote:
As the wankel engineer told my class in university, that the Wankel is great
if you have no pollution controls. Is basically a dirty engine.


Did he say why?

Reciprocating (piston) engines have a built-in energy loss
on every stroke, when they stop & start the mass of the
piston & connectors going up & down. Reducing that mass
would give a boost in efficency, probably not as great as
the gains in combustion technology nor as great as the gains
from higher operating temps due to improved manufacturing &
metallurgy.

There are other types of positive displacement rotative
engines, the Wankel is just the best known one.

One thing I was very dissapointed that has not come up in
public discussionon energy saving: driving habits. Most
Americans have no clue how to drive for fuel efficiency.
Many don't believe their lead foot has anything to with
their car not reaching it's EPA mileage rating.

DSK

"DSK" wrote in message
news
Calif Bill wrote:
As the wankel engineer told my class in university, that the Wankel is
great if you have no pollution controls. Is basically a dirty engine.

Did he say why?

Reciprocating (piston) engines have a built-in energy loss on every
stroke, when they stop & start the mass of the piston & connectors going
up & down. Reducing that mass would give a boost in efficency, probably
not as great as the gains in combustion technology nor as great as the
gains from higher operating temps due to improved manufacturing &
metallurgy.

There are other types of positive displacement rotative engines, the
Wankel is just the best known one.

One thing I was very dissapointed that has not come up in public
discussionon energy saving: driving habits. Most Americans have no clue
how to drive for fuel efficiency. Many don't believe their lead foot has
anything to with their car not reaching it's EPA mileage rating.

DSK


Basically Yup. He said all the pollution controls added up to a lot of
inefficiencies. The spraying of oil inside the piston to cool it. You
could make a more effiecient and cleaner engine now, just because of the
improvement in Materials Science. Better rotor end and tip seals, etc.
Better alloys for the piston.