Diesel-electric cars...

And im not talking like the toyota/honda gasoline hybrids only with a diesel engine inside, i'm talking locomotive type diesel-electric cars. So. What do you guys think the feasibility of designing cars to be much the same as the locmotives are designed?

For those who don't know, diesel electric trains have a 2 stroke diesel motor in them (usually large, but that's understandable) that's conencted directly to an electric generator. The generator then powers electric motors that are attached directly to the wheels of the train. This seems to be a very efficient and compact design, considering there is no need for a 30 speed transmission, and the engine can run at peak efficiency (or idle) all the time.

I don't see why this couldnt work for cars. Obviously a car wouldnt need an engine displacing 1200 liters with a gnerator that puts out 2000 amps at 600volts or anything crazy like that. Compact cars could have a 2 stroke diesel at 1 liter displacement or less to a small generator, midside 1.0-2.0 liters and luxury vehicles 2.0-3.0 liter engines, while light and medium duty trucks could have between a 3 and 5 liter engine, all of these obviously, coupled to a generator chich then powers electric motors attached to the wheels. Even heavy duty trucks (semi's and dump trucks and the like) could benefit from this system... that's why i thought of this in the first place,

Yesterday driving home from school, I saw a semi-truck hauling a railway car of some sort (looked like a rail repair vehicle or something, but its really not that important). The important thing was whatever it was, it was HEAVY! The trailer was sitting 3 inches off the ground at the front, closest to where it connects to the truck, and it actaully scraped the road when the truck took a turn. Now, the point is this truck was stopped at a light when I saw it. When the light turned green, the thing took FOREVER to get going, and make it around its turn. More than half of the time was spent shifting gears! And considering that truck has probably around 20 speeds, that's a waste IMO. Now, as far as i see it, if the truck had been set up like a train locomotive, then it would have gotten to where it needed to go much more quickly and efficiently. Electric motors make their max torque at 0 RPM, so getting moving in the first place wouldnt be a problem, and the diesel engine would be running at *constant* peak torque to drive that generator, in which all of the power would be driving the wheels, while the electric motors themselves would be the transmission, simply speeding up, instead of waiting for a mechanical transmission to shift, bring the engine up to speed, yadda yadda.

So, what do you guys think? Any holes in my train of thought (pun intended:grinyes: )? I personally thing that the oil corporations have such a tight grip on everyones balls that they'll never allow this to happen on their watch; they're making far too much money off of our inefficient gasloline dependance...

I'm not sure that you could fit an appropriate sized electric motor at all four wheels (or two wheels) that would be large enough to have any sort of speed without effecting handling out of the car.

Then put them in the middle and run axles off of them, like in the current hybrids. Easy problem to overcome. I didn't mean to say that the setup has to be EXACTLY the same as a train. To add to that, since a lot of cars have stop and go driving, have a battery system set up for low speeds where its stop and go to save even more fuel. Use regenerative braking along with the motor to charge the batteries and shazam, ultimate fuel efficiency.

sure you could.
get rid of the brakes and use large wheels (thats where the trend is going anyway).

you dont need brakes because the other two wheels could have them and the ones with the electric motors could use the electric motor as a brake.

batteries would go in the place of the gas tank. gas woud go under the hood with the small diesel motor. generator would be attached to back of motor like a trans.

think about it. the rear wheels could be driven by electric motors. they would go in place of the diff and be attached directly to the wheel with a few bolts.

if cars were designed a little differently, it would fit very nicely.

Well, i'd still want to keep mechanical brakes just in case. If for whatever reason there is a short in the main circuit, those motors are just going to freewheel and not slow you down. Not to mention, once you get under about 10 mph, the motors don't stop you worth a shit.
This design would also be an easy way for every car to have AWD. One motor driving the front wheels, one motor driving the rear wheels. And in case one motor dies for whatever reason, you can still drive.

You could probably fit the battery pack and the fuel tank both in the back. The weight of the diesel motor+a generator is enough so that the car doesnt need any more ballast up front I would imagine.

I dont know, I'v been around alot of industrial sites in my life and I know that any electric motor to do this sort of thing is going to be massive. I just dont see this being logical. I also dont know if a diesel engine that small is going to be up to the task of making that much power to feed the electric motors. Nothing is 100% efficient so why use A to power B which powers C? Trains use this setup because of the lenth they are dealing with, and the convience of hookup- its easier to hook up a wire then it is to install seperate engines in each one. I'm not saying it cant be done, because obviously it could, but I see no practical reason.

I dont know, I'v been around alot of industrial sites in my life and I know that any electric motor to do this sort of thing is going to be massive. I just dont see this being logical. I also dont know if a diesel engine that small is going to be up to the task of making that much power to feed the electric motors. Nothing is 100% efficient so why use A to power B which powers C? Trains use this setup because of the lenth they are dealing with, and the convience of hookup- its easier to hook up a wire then it is to install seperate engines in each one. I'm not saying it cant be done, because obviously it could, but I see no practical reason.

They already have those motors in current hybrid cars. The ones on trains ARE massive, but that's because they need to pull thousands of tons of mass. For a car - 2 tons. Big rig, 40 tons. I dont see why you wouldn't think a small diesel engine could power a car. A current honda 2.2 diesel motors makes 250 torques and 140 horsepower. That's MORE than enough to run that car, and that would be plenty of power to turn a generator. This would translate straight into the electric motors with very little loss. Probably less loss than a typical mechanical drivetrain through a transmission. Keep in mind that the motor i just mentioned is a four-stroke diesel. The torque would be roughly doubled if it was a two-stroke diesel. But since you don't need 500 torques to get an accord going, you could make the engine smaller. Saaay, a 1.3L 2S diesel?

And the reason trains do it is because its much easier to run electric current through cables to motors than it is to drive a 50 speed transmission through 4 to 6 sets of differentials, with the front and rear sets needing to move independantly from each other and the engine body itself. It's also more fuel efficient to run the motor at peak torque and let the electronics and the electrics hand the transmission of the power. That's why these trains only use ~1.5 gallons of fuel per mile when pulling a load. That's pretty damn good if you ask me. Granted, the fact that they are on rails helps a lot with the friction aspect of it, but i'm sure we could see similar gains in the general automotive fleet, and ESPECIALLY the trucking industry, because big rigs are basically road-trains.

Well, i'd still want to keep mechanical brakes just in case. If for whatever reason there is a short in the main circuit, those motors are just going to freewheel and not slow you down. Not to mention, once you get under about 10 mph, the motors don't stop you worth a shit.
This design would also be an easy way for every car to have AWD. One motor driving the front wheels, one motor driving the rear wheels. And in case one motor dies for whatever reason, you can still drive.
well i said you would have mechanical brakes in the front (where most braking occurs anyway)
i still think that individual motors is best becuase it eliminates all the need for differentials and the like.
i guess inboard brakes are best, and they could be used to recapture energy thru regenerative braking.
this is all really hypothetical anyway...

I've pondered this concept for a while too. Ever since I saw my first Diesel Electric Locomotive powering away from a dead stop without any shifts. Just "BWAAAAAAAAAAAA!!!!!" and the whine from the turbo, of course. Upon researching the means by which the diesel engine is connected to the wheels (or 'trucks', as they are oft referred to as ), I had a "well duh!" moment and wondered why I didn't see this trick setup in any other vehicle.

Especially Big-Rigs. The huge oversize ones might have back-to-back transmissions, with like 30 gears possible. That's insane! And its the very reason why Loco's don't use mechanical transmissions. To handle the torque it takes to get the train moving, and to have the ratio-adjustability to get up to a decent top speed, the transmission might take up another car all its own. Can you say impractical? I knew you could.;)

Now, why haven't we seen this applied in automobilia? All I know is: "I don't know." But if no one else does it soon, I'm gonna build my own.

well it surely would be a good idea.
gas IC engines get max efficiency at full throttle.
diesels eliminate the throttle, but i would imagine are more efficient at max load.
of course a turbo is mandatory. lol

well it surely would be a good idea.
gas IC engines get max efficiency at full throttle.
diesels eliminate the throttle, but i would imagine are more efficient at max load.
of course a turbo is mandatory. lol

Full throttle at peak torque, that is. Same with diesels. It's not mandatory to have turbos on a four stroke diesel, but it helps. It is on a two stroke though.

I personally think have an individual motor per wheel would be a bit excessive. That would really weigh down the car and make the electronics complicated, but then again, it may be the best approach. Who knows, they havent made any cars like this yet.

Hmm. Lets see what the future holds..

The problem with converting all of your engine's power to electricity is that its INCREDIBLY inefficient. As much as 80% gets lost to heat, light, and sound energies.

The engine itself is only about 87% efficient at getting the energy from the fuel, and then the generator only effectively turns a small fraction of that into electricity

Locomotives use that system mostly because they have to, but its incredibly wasteful. If you were to impliment this in cars you would end up burning many times more fuel to get the same output at the wheels.

Even alternators and A/C traction motors?

Yep. Any time you change states of energy you lose a bunch. No getting around it. In the 80's the big thing was magnetic superconductors that were over 90% efficient, but they still lost up to 10% depending on the transfer protocol. Just getting electricity from the power plant to your house loses over 80% of it, and that's not changing states, its just travelling 20 miles through electric wires.

Even if you made it 99% efficient, you'd still be losing 1%, meaning for the same output to the ground you would theoretically have to burn 1% more fuel in the engine to get it

there was a automotive college class that made their own diesel hybrid using a VW TDI engine, although I believe they still kept the engine capable of moving the car....although I'm not positive about that....that had rather amazing numbers. Acceleration and mpg.

I've always been mystified why the hybrid craze has yet to see (that I've seen) a diesel engine. Seems rather obvious to me that that would be more effective. I just assumed its something to do with the US' disdain for diesels in cars.

Yep. Any time you change states of energy you lose a bunch. No getting around it. In the 80's the big thing was magnetic superconductors that were over 90% efficient, but they still lost up to 10% depending on the transfer protocol. Just getting electricity from the power plant to your house loses over 80% of it, and that's not changing states, its just travelling 20 miles through electric wires.

Even if you made it 99% efficient, you'd still be losing 1%, meaning for the same output to the ground you would theoretically have to burn 1% more fuel in the engine to get it

ah crap! You are 100% correct (as usual) Curtis. Here I was thinking that powering a generator/alternator was quite efficient. Well, that throws that whole idea out the window. Maybe once superconductor technology advances this would be more feasible, (room temperature superconductors and the like, i'm gonna read up on them right now)

I've always been mystified why the hybrid craze has yet to see (that I've seen) a diesel engine. Seems rather obvious to me that that would be more effective. I just assumed its something to do with the US' disdain for diesels in cars.

Amen. I have to chuckle at the fact that VW TDIs are making putting more power to the ground then hybrids and (since most hybrids aren't getting anywhere close to their advertised mpg) the diesels are getting better mileage.

Plus, the diesel is simpler than a regular gas car whereas the hybrid is intensely more complicated. Its a buzzword just like SUVs, so look for dumb buyers to keep on buying into the hybrid craze until they finally come to their senses and realizing they're wasting more energy by driving one.

I get a kick out of the "clean air" vehicles being granted commuter lane access. They're still burning fossil fuels, while biofuels put fewer net emissions into the air... but biofuel vehicles aren't granted access to the commuter lane. So, do you blame the dumb public, or the dumb legislators?

grrr...

Off my soapbox now.

So if I say that converting A into B is ineffiecnt you shun me, but when Curtis says it you promptly agree? Odd.

So if I say that converting A into B is ineffiecnt you shun me, but when Curtis says it you promptly agree? Odd.
what, so you want an apology?

curtis explained it better.

I'd rather have a piece of cocoanut cream pie.

i prefer lemon merangue pie.
coconut is only good in german chocolate cake when spread on top, mixed in with buttery chocolate icing.
get it right...
lol

You know german chocolat cake is accually from Texas? The woman who came up with it had the last name "German" and the recipee was published and became known as "German Chocolat Cake".

So if I say that converting A into B is ineffiecnt you shun me, but when Curtis says it you promptly agree? Odd.

Well, you didn't explain that the efficiency of mechanical-electric conversion is only 20%, and that's on a good day. I realized that some would be lost, but i didn't realize it was THAT much, which Curtis pointed out. No offense meant, mate.

But! I've been doing some reading, and apparently they've designed a superconducting generator that's >99% efficient, and half the size of the conventional generator of the same output. So maybe one day this hybrid system would be feasible.

I'd rather have a piece of cocoanut cream pie.

cocanut cream pie sucks!

(unless curtis likes it, then its my favorite) :icon16:

cocanut cream pie sucks!
already established that. coconut german chocolate cake rules

unless curtis likes it, then its my favorite
well naturally.

cocanut cream pie sucks!

(unless curtis likes it, then its my favorite) :icon16:

The Curtis does indeed like coconut cream pie. It is his FAVORITE. Commence kissing up, Uncle.

We need a smilie that is something like :kissass: :D

But, as we're finding out, the Curtis doesn't necessarily have all the latest info. :scratch chin:

Are we discussing Diesel-Electric German Chocolate Cake now? or are we just (hilariously) off topic?

We need a smilie that is something like :kissass: :D


oh....I could think of one that would work well with that one http://www.zrxoa.org/forums/images/smilies/moon.gif

Just joshing you.....don't hit me :eek:

I was wondering the same thing a while ago but i was thinking of a different powerplant. I wanted to use a turbine engine for a few reasons, 1) it's more efficient than a reciprocating engine, 2) it's most efficient at a constant speed so this job is perfect for it, 3) you can use a mulitude of different fuels to power it, 4) as was previously said, buzz words get people to buy into it, what sounds cooler than saying "my car has a jet engine in it".

now, are you positive that the mechanical-electrical conversion efficiency is as low as 20%? that seems rediculously low to me. if it was higher i was thinking of doing the same thing where the engine runs at a constant speed and charges batteries then the electric motors run off of the batteries.

this would be a good idea for a car that doesn't do alot of repeated accelerating, so for people who drive mostly on highways and stuff like that. this is because you use the most energy when accelerating and the least when going at a constant speed. so the batteries would be drained more quickly from a stop but they'd have time to be charged after a bit of driving at a constant speed, or at least that's what i'd hope.

also, you could have electric engines that are capable of accelerating very quickly but do not need to drain the batteries as quickly if you want to conserve energy and drive slower.

another advantage is that engine placement would be more flexible. you don't need the engine to be placed in any particular manner because the wheels and the IC engine are connected by wires. this means you can have better aerodynamics which also helps with fuel economy. turbine engines also tend to be smaller than their reciprocating counterparts of the same power, meaning they will take up less interior space and you can have a better interior.

so yes, this system is more complicated, it would take alot of work, and it wouldn't be reliable at first, but what new technology is? if i can find an efficient way of transfering energy from the engine to the motors i'll try to build this. i mean i have access to a full machine shop and i have a whole chip-making facility at my university (as in you can design pretty much any chip you'd like, then make it on campus) and access to rapid prototyping. i've also got access to a wind tunnel, and a plethora of other facilities that i haven't discovered yet. they'll be available to me next year.

i want to start with a small car like a mazda miata, use the regular engine configuration (front engine, rear drive), maybe even use a differential to make it even simpler so i just hook up one electric engine to the diff, anything to get this project running and see how it does.

i just though of another thing, batteries. if i go with this setup ill need to put a bunch of bateries in the car. since it'd be a small engine with small power i don't think heat would be a huge problem, i'm not going for extreme performance, im going for reliability and efficiency so i would hope it would be relatively cool. so i could probably have the batteries close to the engine (as in in the engine compartment) with insulation between them, without having them melt or have serious problems.

and i need to figure out how to muffle the whistle from the intake, i'm thinking just having it suck straight from the front so that it's as far from the driver as possible. or have it suck from right behind the radiator or oil cooler since turbines like sucking hot air.

anyways, any comments on this would be great, if anyone sees anything wrong with this tell me. this pretty much all relies on the efficiency of mechanical-electrical efficiency.

I thought turbine engines aren't nearly as efficient as IC's. They are extremely good at power/weight ratio, which is why they are so popular with aircraft. But a IC prop plane is way way more fuel efficient

i don't remember where i read it but it said turbines were more efficient. and with planes you're using thrust instead of shaft power so that might play an important role in the efficiency. the problem with pston engines it that you have to accelerate the piston down, then decelerate it, then accelerate it up, then decelerate it. all those accelerations (both positive and negative) take energy, with a turbine engine you only accelerate it in one direction. although i don't know how efficient they are at transferring gasses moving in one direction into shaft rotation.

another alternative is a quasiturbine, just for the hell of it to make it sound cool and to try something else. if i'm going to make something radical, might as well make it really radical as long as it works. but i would just use a diesel engine to accomplish it.

Turbines are more efficient than IC engines, they can commonly have efficiency approaching 40%. Some of the more cutting edge turbine technology is closer to 60% efficiency.

The biggest problem with automotive applications is the response time of the turbine is comparatively slow. So there is significant delay between when the driver pushes the "gas-pedal" and the engine delivers more power, and vice-versa.

Similar to an IC engine a turbine is best suited to operation at a constant speed.

wasnt there a turbine powered buick or something a while ago.
i remember i saw something on something like that. it was a concept car i think.
how would an automotive turbine work anyway?
what would happen to all the hot exhaust gasses?

wasnt there a turbine powered buick or something a while ago.
i remember i saw something on something like that. it was a concept car i think.
how would an automotive turbine work anyway?
what would happen to all the hot exhaust gasses?

I would guess they are exhausted in a similar manner as with an IC engine.

Keep in mind that it is not the exhaust gases that would propel the car, that is unique to “jet engines”. Instead the turbine spins a shaft that is mechanically linked to the wheels.

There are probably better pictures out there, but here is a cross-sectioned gas turbine used in the M1A1 Abrams tank.

http://tanxheaven.com/m1agt1500/AGT1500_ex%20view.jpg

Rover made a turbine powered version of the old P6.
It worked, very well, had only one forward gear, and top speed of well over 100mph. Considerably faster than the orginal V8 powered car. Even got better fuel economy.
Just two down sides, the engine was not very responsive, and when it went it WENT!.
And the the heat generated was terriable. They had to duck it out the top of the hood, and haze would often obscure the drivers view.
Ducting it out the back of the car caused problems for anyone stopped behind it, or even walking behind it.

There is a company in the states that makes limited production Turbine powered bikes.
They have big problems with the exhaust melting the bumper of anyone who stops to close to the back of the bike.

You know. I bet a good use for that waste heat caused by a turbine motor would be to power a stirling engine... Wham bam, extra efficiency right there. Kinda tight on time, i'll extropolate later.

or you could do something much simpler, get a heat exchanger between the exhaust and the intake. turbines like hot air so it would bot cool the exhaust and heat the intake.

by the way, the turbine bike you're talking about is the Y2K, it's got a 300hp turbine engine and does 0-222mph in just over 14 seconds.

by the way, the turbine bike you're talking about is the Y2K, it's got a 300hp turbine engine and does 0-222mph in just over 14 seconds.
yes....and the Y2K gets horrible mileage too :wink:

4-6 mpg

http://www.popularmechanics.com/automotive/jay_leno_garage/1302876.html

my wimpy 250HP bike gets mid 40's :)

true but that's a 300+hp engine that's being used completely differently. i'd only look for about 70-100 depending on how much i'd need to charge those batteries. the thing is that you don't need to accelerate the gas engine with a generator-electric motor setup so you waste less fuel.

how can it get such bad mileage.
if it came out of a helicopter, it would have to run for a LONG time.
helicopters cant be carrying tons of gas with them.

can't speak for helicoptors, but most jet planes rate them by gallons per mile instead of the other way around :D

Its true that turbine's are more efficient in how they extract BTUs from the fuel, but not how they transmit BTUs into HP. The exhaust from a car accounts for about 20% of the BTUs of the combusted fuel. In a turbine, it accounts for nearly 75%. It all depends on what you do with the BTUs released by the turbine.

If you use the exhaust (like a jet engine) you're using most of the BTUs. Not only are you using the spinning shaft, you are using the thrust of the expanding gasses. If you are simply using the shaft torque (like you would in a helicopter or a car), its very inefficient. All that heat is wasted out the exhaust unused.

I'm pretty excited about hydrogen-electric fuel cells. I don't know tons about them, but its an electric "generator" that makes an electric potential by putting hydrogen ions near a permeable membrane. The only real emission is water and hydrogen, and (provided the hydrogen is harvested from the surface instead of from crude oil) still makes zero net emissions.

They aren't overly efficient right now, but they have the potential to be... but even if they aren't, its a basically free fuel that already exists in our atmosphere. If we don't extract any energy from it the first time, its still there for us to do it again with little or no consequence.

I'm also very excited about biofuels. When you burn fossil fuels, you're digging up HCs from underground, burning them, and putting them in the atmosphere. That is seriously upsetting the balance. Combine that with deforestation and you have nothing to "scrub" that junk out. Biofuels make HC out of existing water and CO2 already above the surface and in the atmosphere. So the only things that we put into the atmosphere are things that the plants we grew already took out of it. We would have to have enough plant life to scrub out everything we put into the atmosphere.

Recent studies by the ARB and EPA have pointed to the fact that if we had entirely fleets of biofuel vehicles (in specific biodiesel and ethanol) then the increased NOx emissions (from the fact that ethanol requires higher compression and diesel already has high compression) would not be as much of a greenhouse threat. Basically, we've filled the air with so much junk that now we have to be super careful about what we put in it. If we hadn't messed it up, NOx would be a relatively harmless set of gasses.

I don't see how anyone can ignore the fact that we're bringing up billions of barrels of HC from underground, burning it, and putting it in the atmosphere... and then we try to make cleaner ways of burning it??? I say stop burning it and use the biofuels already in existence in the air.

The only problem with hydrogen is that it's VERY costly (money and energy) to extract it, and it's very difficult to store. The most efficient way to get hydrogen is to crack it from the oil in the ground, or from methane gas, but that kinda defeats the purpose, no? To extract hydrogen from water takes a LOT of energy because a lot of it is lost (its only about 50-70% efficiency to electrolyze water with electricity, and that doesn't take into account the inefficiency of making the electrical power in the first place, as we discussed before).
On top of that, hydrogen is also a losing battle when it comes to storage. Any material is basically a sieve to hydrogen, because it is the smallest atom and quite simply passes through the walls of the container with relative ease. Not to mention I wouldnt want a tank filled with liquid hydrogen pressured at 3000psi. A way around this is using hydrides, metals that absorb hydrogen and can store it easily, but that's still being developed.

I'm with you all the way with the biofuels, however. I feel that that is the best option for future energy needs for the world. If room temperature superconductors are finally discovered, the whole world with revolutionize (well that, and feasible nuclear fusion reactors). Even relatively poor countries could have more than enough energy to support themselves and advance. Heck, with fusion reactors and RTSC's the world could be completely electrically based.

The problem with converting all of your engine's power to electricity is that its INCREDIBLY inefficient. As much as 80% gets lost to heat, light, and sound energies.

The engine itself is only about 87% efficient at getting the energy from the fuel, and then the generator only effectively turns a small fraction of that into electricity

Locomotives use that system mostly because they have to, but its incredibly wasteful. If you were to impliment this in cars you would end up burning many times more fuel to get the same output at the wheels.

Your conversion efficiencies are way out. There's no engine that can deliver 87% effciency.

A very good diesel can get almost 40% of the fuels energy into output at the crank.
An electric generator efficiency depends on the type, but you can do better than 2/3rds.

Electric motors can do upwards of 95%.

But the weight and cost are the biggest problems for a passenger car.
For big trucks, you won't beat the efficiency of a mechanical transmission.

Its not the effiecency of the electric motor in question, its the converting from mechanical to electrical that is efficient.

Your conversion efficiencies are way out. There's no engine that can deliver 87% effciency..

Sorry, I should have clarified. I meant thermal efficiency, as in the number of BTUs stored in the fuel versus how much the engine releases during combustion.

Its not the effiecency of the electric motor in question, its the converting from mechanical to electrical that is efficient.

Generating power isn't that bad.
Your 12v alternator will do maybe 60% efficiency, large generators running at constant speed will beat 90% efficiency.

Sorry, I should have clarified. I meant thermal efficiency, as in the number of BTUs stored in the fuel versus how much the engine releases during combustion.

So you're talking about the last 13 odd % being released outside the combustion chamber?

*edit* er, wait. i need to look stuff up.

Interesting thread...and a few notes:

I remember in the days of the VW diesel rabbit, popular mechanics had an article about a diesel electric version, with a regenerative braking system/flywheel arrangement, and they were speculating about 150+ mpg efficiency. Of course, at the time, the cost of fuel was .60/gal, and they also speculated that it would be difficult to get interest at such low fuel prices.

Now, the world turns and it deserves a new look.

I also have been tracking some very interesting rotary diesel engine technology, and the web site claims that conventional IC engines only achieve volumetric effiency in the 8-9% range, while this engine claims 30%.

The web site is www.regtech.com

Lastly, Dodge was planning a US introduction of the 2007 Caliber with a diesel engine option (reportedly was to be sourced by VW) coupled with a CV transmission (CVT), which was purported to be more efficient and simplier than current options (ie snowmobile). The new diesel engine emissions rules (specifically NOX) prevented the 2007 release, but purportedly next year. Although I am NOT a mechanical engineer, the articles on the CVT had been very positive on the higher effiency of the CVT than conventional transmissions due to less losses through no gears being meshed, no torque converters, etc. A simple test is the heat generated by transmissions, thus indicating friction loss. CVT also has the potential of keeping the engine at the most optimum operating levels/rpms since it has potentially infinite gear ratios.

So, wouldn't a rotary diesel electric engine coupled with CVT be a killer combination?

Ed.

So you're talking about the last 13 odd % being released outside the combustion chamber?

No, I'm talking about the 13% that isn't released at all. Unburned HCs are one way, and it also makes other compounds out of the fuel besides simply combusting it.

And, yes, there is a certain percentage that is released outside the chamber. How about the continually burning HCs in the exhaust and the catalyst?

I also have been tracking some very interesting rotary diesel engine technology, and the web site claims that conventional IC engines only achieve volumetric effiency in the 8-9% range, while this engine claims 30%.

The web site is www.regtech.com (http://www.regtech.com)

Lastly, Dodge was planning a US introduction of the 2007 Caliber with a diesel engine option (reportedly was to be sourced by VW) coupled with a CV transmission (CVT), which was purported to be more efficient and simplier than current options (ie snowmobile). The new diesel engine emissions rules (specifically NOX) prevented the 2007 release, but purportedly next year. Although I am NOT a mechanical engineer, the articles on the CVT had been very positive on the higher effiency of the CVT than conventional transmissions due to less losses through no gears being meshed, no torque converters, etc. A simple test is the heat generated by transmissions, thus indicating friction loss. CVT also has the potential of keeping the engine at the most optimum operating levels/rpms since it has potentially infinite gear ratios.

So, wouldn't a rotary diesel electric engine coupled with CVT be a killer combination?

Ed.

I've just checked out that rotary site. The claims they make are very vague. Comparing power/weight to a wankel engine (wankels are terribly inefficient) and making fuel efficiency claims with no figures at all to back them up.
If they had impressive figures on BSFC (brake specific fuel consumption, what weight of fuel it takes to produce 1 kw for one hour) then they'd be shouting about it on their website.
A very good modern piston diesel engine has a BSFC 200g of diesel per kilowatt hour. The 20 year old engine in my truck can manage 220 g/kwh.

The combustion chambers are pie shaped, making for cold corners and a bad surface/volume ratio. This makes it hard to get a clean burn, hurting fuel efficiency and emissions performance.
Each vane has two sliding ends. That's a large and convoluted sealing surface.

We're at a stage with the piston engines where they're highly refined, there are many "alternative" designs out there with fantasic claims but I have yet to see one that is even competitive.

There's a New Zealand inventor currently trialling a different form piston engine. It's using a sinusoid plate instead of a crankshaft. The idea isn't better efficiency, just better packaging for certain applications.

Thanks for the reply.

Granted, the reg tech stuff is only in development, but looks interesting nonetheless.