Efficiency Improvements for Internal Combustion Engines

[autoteach]

Once again, effects of CR on power
Engine Compression Ratio - Tech - Popular Hot Rodding Magazine

Now, you dont have to believe it at all. In fact, you dont have to read it. But ignoring facts doesnt make your imagination reality. That is only unfortunate for you. Diesel and gasoline engines benefit greatly in their efficiency from higher CR's.

[user removed]

Agreed autoteach.

http://www.greencarcongress.com/2010...1020.html#more

The new Mazda has a CR of 14to1 close to what Indy Cars run on alcohol.

Higher than even the best engines in the 60s running on premium leaded gas.

regards
Mech

[user removed]

The free piston also eliminates the leverage concerns with rods and pistons. The calculated efficiency in the EPA docs from 5 years ago was 58%.

http://www.sunpower.com/lib/sitefile...ns/Doc0083.pdf

http://www.freepistonpower.com/fp3.aspx

Free piston engines can also be configured to be linear alternators, which if they ever get to that range of efficiency could be the combination for a battery electric car with a free piston engine replenishing the battery or driving the wheels directly, with a regenerative hydraulic braking system that worked on the non driven axle.

That would create an existing platform that could easily be transformed into a pure electric, hydraulically regenerated vehicle when battery technology gets to the point where range and cost-life expectancy, and safety issues are resolved.

regards
Mech

[dcb]

Originally Posted by Old Mechanic

..
Lets look at it another way, bsfc for most small passenger car diesels are right at 200 or just slightly lower in their sweet spot (generally speaking). For gas engines it's right at 250 (also generally speaking). Take 200 and divide that by .88 and you get 227.2, round that off to 227 and you have more than 50% of the difference due to the energy content of the fuel.

sorry dude, but bsfc is by weight (grams), not volume, and gas and diesel are about the same in the weight department (gas is actually a little higher)
http://upload.wikimedia.org/wikipedi...gy_density.svg

I think UFO explained the effects of increased compression ratio pretty well, higher expansion ratio=more energy extracted.

[user removed]

Looks similar to your original configuration Neil.

http://www.youtube.com/watch?v=l4xup...eature=related

regards
Mech

[user removed]

Super-Efficient Free-Piston Engines Could Replace Traditional Gas and Diesel Engines : TreeHugger

If they can get 50% direct electric conversion imagine what that would do for the volt or a smaller one for the leaf.

regards
Mech

[autoteach]

Well, not quite the same. This is a turbine, his was a piston engine.

[user removed]

Originally Posted by autoteach

Well, not quite the same. This is a turbine, his was a piston engine.

Understood but the configuration looked similar.

regards
Mech

[user removed]

The original atkinson cycle engine which was invented to get by Otto's patents.

Animated Engines, Atkinson

regards
badger

[autoteach]

Atkinson is what I would consider to be "high overlap". Dynamically intake charge and compression would increase with engine speed.