New internal combustion engine could boost electric cars

"Free piston" engines suffer from high promise and low delivery. In this case, "120 lbs" for "40 hp" which is an abysmal power-to-weight ratio.

Friday, I took delivery of a Hirth F23, two-stroke:

• 50 hp @6150rpm
• 68 lbs w/o reduction gear (not needed for generator)

More importantly, there are multiple sources on the market. I'm not trying to ignore emissions and specific fuel consumption but first you need an engine.

I will not be pursuing these in my application but direct fuel injection can handle specific fuel consumption. As for emissions, centrifical separation before a catalytic converter should work. The oil laden flow cooled would cycle back to the intake and help cool combustion temperatures. But this is not areas I plan to do any work.

Bob Wilson

 

Rav Long Ranger

 

4 or 5 years? and they talk in the article about the snail's pace of battery development. i don't even buy green banana's!

 

The story is from Fox "News". It therefore cannot be considered credible unless confirmed by other sources that don't disdain factual information.

 

Exactly. When I noticed the source, I didn't bother to read the article. Waste of time.

 

Perhaps a better source (with attribution at the end): Green Car Congress: DLR team develops demonstrator of free-piston linear generator as range extender for EVs; technology transfer to Universal Motor Corp.

 

Strange but I don't consdider anything news UNTIL I hear it from Fox. At least I know it's not liberally biased.

 

That seems kind of limiting though. Compare the Fox article with the Green Car Congress article. The latter gives you the real name of the research organization and a link to a translation of the research paper.
There's an awful lot out there that probably doesn't make it into Fox News, and I suggest that it might be worth reading too.

[Edit] And why does Fox have it in the Lifestyle/Leisure section?

 

Essentially, every electric car needs to have a backup internal combustion engine like the Chevy Volt. It would take the electric car mainstream and make it much more practical. The Tesla should have a backup internal combustion engine like this.

Otherwise, you can get stuck when you unexpectedly run out electrical power because you used amenities like an air conditioner in hot weather, or the heater in cold weather, or did not have time or chance to charge the engine.

The Free-Piston engine is interesting in that the engine is linear, not having to drive a crankshaft as in a conventional engine. This allows it to be installed in creative ways in a car where a regular engine may be to bulky.

 

Most of my "information" is sourced from the liberal "psuedo news" sources: Huffington, ABC and NBC. For anything even remotely political, it's just not until I get affirmation from FOX, that I consider it trustworthy. There's an awful lot going on in this country that's NOT being reported on the Liberal media and that scares me to no end. I listen to many liberal pundits for the humor; ZERO Conservatives (there's nothing funny about them and I certainly don't need anyone to help me form my opinions.).

 

Nonsense. You add a whole level of complication when you add an engine and all the support structure needed.
It is difficult to unexpectedly run out of range unless you are stretching the limits of the range, in which case you need to plan for charging, or use the correct tool for the job.
I am just fine with range extended EVs, plug in hybrids, or what ever you want to call them. Just don't take away my option of a vastly superior (for me) pure EV.

 

That was a fitting choice of words.

 

I read about this kind of engine some time ago. Ah, November last year:

Green Car Congress: GM and U Mich receive patent on plug-in series hybrid/extended range electric vehicle powertrain using multiple free piston linear alternator engines

Add it to the long list of "stuff you hope works eventually".

 

That depends on what you are trying to do. You put two of these together and you get 80 hp, 4 cylinder, 2 combustion chamber ice, that can operate in 2 or 4 cylinder mode for 250 lbs. That's only 30lbs more than the 98hp prius ice that does not have cylinder deactivation and must carry mg1's weight as well. I'm sure the 1.4L + generator in the volt is heavier and is not flex fuel. Questions do matter on how much emissions control this will need. 250 lbs really is not that much weight to add to an already heavy bev. The leaf is 3350 lbs, one 2 cylinder addding 200lbs for gas/ice/emissions control won't affect weight significantly.

di and electronic controlled variable lift allow some drastic improvements in two-stroke design, but really fuel efficiency is higher in 4 stroke when you don't need the power to weight.

sounds like a cool project. I really wish CARB/EPA would relax the rules for range extenders as they do not operate at all times. There is some vary interesting technology, but complying with the rules, especially SULEV to get an HOV sticker, means you can't pursue many of the really interesting possibilities.

 

My apology for my earlier response post. I too was bothered by the source but sometimes I'll take a peek to see if a touch of reality might have shown up. But Friday I got this puppy:

I was distracted as I am designing a test stand to record:

• propeller torque
• propeller rpm
• engine rpm
• two cylinder head temperatures
• two exhaust temperatures

So when I read something about a new 'wonder engine' and its performance is worse than this puppy . . .

Bob Wilson

 

What are you going to use that for Bob? a microlight or bigger?
I'm interested to know what you get out of it so please be sure to post yeah

 

Re-engine N19WT:

According to the Hirth engine specs, the specific fuel consumption of the liquid-cooled, 3502 meets my requirements:

This liquid cooled engine has significantly improved BSFC over the air-cooled versions. But with fuel injection, oil injection, and a flight adjustable, variable pitch prop, I'm looking at significant improvement over the HAPI 1835cc it replaces. It will be as expensive as the 'tractor' engines in current practice but perform significantly better . . . if I've done my engineering analysis right.

It is an interesting technical challenge but I think solvable. If I had an EV, I probably would but I don't and leave it as an academic exercise. <grins>

Bob Wilson

 

I used to work with a local company called Cosworth who produce a really interesting range of two stroke diesel engines for UAVs. Power from 3 to 60hp I believe. They quote BSFC of 0.45lb/hp/hr and have a 13hp variant that weighs in at 16.5lb.
I have a feeling they are rather expensive though, but not as expensive as the F1 engines they produce lol

 

Let me give some hints:

• liquid cooled - improves BSFC
• direct injection - improves BSFC and allows Lambda control
• vortex exhaust separation - separates oil and soot for cooled exhaust, reducing oil consumption and the catalytic converter HC load
• O{2} sensor on 'clean' exhaust flow - this feeds the catalytic converter
• computer controlled - optimized for emissions and efficiency
• ON-OFF full-throttle, cooled EGR - after warm-up, it cycles ON and OFF to operate at peak BSFC only! Throttle has two positions, start and power
• vehicle buss communications to match source to load

COTS:

1. Hirth liquid cooled, two-cylinder, 3502
2. Tesla style motor as generator, self-exciting
3. Microcontroller of choice
4. Catalytic converter

Where GM screwed up the VOLT:

1. Battery took 3d seat in back - too much battery
2. Mechanical link to wheels

Ideal vehicle for user 'range extender' -> LEAF.

Bob Wilson