dieselcarpenter

I would hate to see the sticker on a car with electric valves, they would have to be built so rugged and reliable the costs would be really restrictive IMO. If they fail, (a regular occurrence in todays consumer electronics) the motor would be toast I know same thing with belts and chains, but they are far less prone to failure, hence the high cost of making an electric valve which never fails. (or at least has a lifespan equal to mechanical valve-trains)

I always understood the diesel-electric setup as a more efficient torque/traction arrangement as opposed to a fuel savings. Electric motors have almost instant acceleration characteristics. And they want to go the same speed no matter the load. There is no free lunch in the set-up thats why when locomotives accelerating you hear the diesel engines accelerate as well, the rpm's are more efficient but the load on the generator still loads the motor. Am I wrong? This is how I have always understood it to be. As for regen braking they could carry a dedicated battery car and then reuse it for later, the cost in extra weight may not be economical though.

As for the Prius, they do get good mileage in town. on the road though (freeway) they are less efficient than a TDI VW. Best we got between here and WA was 35.5 mpg with little regeneration. (with coasting down hill!!) I agree they need more batteries, but its a trade off of weight/room. Not to mention the environmental impact of the battery production/disposal process.

A diesel electric car/truck would be a real tire smoker though, It would be awesome! That traction motor would want to be going as fast as you tell it the moment you tell it. Plus the rotating components would be mostly gone, which equals a more simple car. But I don't know how they would fair on MPG. Four wheel electric drive sweet!! All IFS with gear reductions!!

!!Personal Opinion warning!!

I think the ultimate clean, powerful, and super efficient electric or hybrid setup for car/truck would be a mini nuclear reactor gen-set. Ya ya I know, nuke-waste and accidents/terrorism, well invent a space elevator so we can efficiently dispose of spent fuel into the sun, and armor the cars, along with computer AI to avoid accidents. But think of it, drive your car/truck for 5-10 years without fueling, when done just swap out cores, quick overhaul of traction motors and cooling systems and off you go! By the time we had this, I would like to think we had peace on earth

The other thing I have heard is using ceramic components in the motor. Change the thermal dynamic properties and you can run 300 miles to the gallon. (so Ive heard)

Never have liked the MDS Idea, seems like the whole motor is rotating but only part is working, Abnormal wear and balance would be my concerns, besides, if I pay for 8 I want to use 8!

farmer0_1

saw a show about future cars on cable the other day and along with all the regular stuff they had a couple guys working on a compressed air powered car i like the idea because refueling at a station could be fast as changing tanks and no waste batteries. years ago saw a dragster down in a florida musuem think it was Garlits stuff it was air powered. and at home overnight you could plug the car in to air up overnite. and if the frame would hold the compressed air etc.

wcbcruzer

Locomotives also use hybrid technology because the rpm range is so small on such a huge engine (only like 800 rpms). Thus, they would need many many gears to get going, which is not practical. Efficiency of a good diesel engine is about 30%. to store energy in a battery you lose about 10% and to retrieve it you lose about 10%. Electric motors also have an efficiency of converting electricity into mechanical work. If you multiply all that up you'd get your efficiency rating in a hybrid (.7 x .9 x .9 x ...). The only reason the Prius gets better mileage, which is actually about 10 mpg better, is because the engine is constantly cycling on and off and it utilizes braking power to recharge the batteries. If the engine ran constantly I don't think the efficiency rating would be much greater than a straight gas-power car of the same size.

pronstar

Electronically operated valves have already been proven by Johnson Controls and others in prototype engines, and are in the final stages of study.

International has already stated that they'll implement them in a diesel engine.

Dangerous Dave

I don't think a series hybrid poses THAT much of a challenge. As long as we aren't thinking of neck snapping drag racing power at least.

I remember reading in Car and Driver about a new way to do valves that was able to change easily with rpm etc.

Fortunately my '03 gets a bit better than 19mpg average, as I couldn't get a new series (or parallel) hybrid anyhow.

GJTJ

Saw several articles over the past couple of months on diesel hydraulic hybrids.

http://www.greencarcongress.com/2005...ton_and_p.html

http://www.nytimes.com/2006/06/25/au...rssnyt&emc=rss

Basically uses a hydraulic pump when braking to charge a nitrogen filled accumulator to store energy instead of a battery. The energy is then reused to drive the hydraulic pump for motive power.

I believe its less expensive to implement than an electrical battery system and there are no issues with environmental impact with batteries and their recycling.

PoorMansCat

LeTourneau has been building large mining equipment using diesel electronic technology for 30+ years now. They use , or were using, large Cummins engines for the fuel power. They use traction motors for power and braking.
As for trains, I've worked on MANY diesel electric hybrid trains in the past couple of years. I think those are made by Railserve, or maybe its Railpower... cant remember which. They use a Cat C-9 generator package that charges a 720v battery bank. The train is powered by the batteries, and when the control system senses the batteries are discharged to a setpoint, the engine automatically fires up, goes thru a brief warm up cycle, then starts throttling up and begins charging. The more discharged the batteries, the more it throttles the engine all the way to rated speed. When charged, the engine throttles down, goes thru a cool down cycle then shuts off... Pretty neat system. Its amazing how quiet these units are when you see it come down the tracks right by you. You see them, you feel the ground moving, but you dont hear them...

Raspy

I think you are referring to VVT or variable valve timing. It's on many new cars these days and is a step up from the normal system in that it can change the valve timing to match the RPM and produce a better torque curve and better mileage. What it does is rotate the cam to a slightly different position and can, on some of them, rotate the intake and exhaust camshafts separately. But it's a far cry from electric actuation which gives MANY more features like throttling etc. Electric frees the valves completely from the crank and does away with the camshaft and cam drive. Way cool.

As with any new technology some will say it will cost more, or be unreliable, or whatever, but it is the way of the future and will make engines more efficient, smaller and lighter.


John

Dangerous Dave

I'm not sure I could ever find it again but "slide valve" sticks in my mind.

sled4fun

Are you thinking of the old *****'s Knight engine. That was a favorite of my fathers. He said it was like listening to a sewing machine run.

Found this link that shows what it is. I wish this place was in the states as I would like to visit it.

http://www.powerhousemuseum.com/coll...se/?irn=208614

Dangerous Dave

no, not that.

I'll try to find the correct magazine...

mj007

Yeah, years ago I worked for an IHC dealership and went to several service schools on the IH Hydrostats and remember that IHC recommended using a gear drive for field work; the Hydros for 'What-U-Said'.

sled4fun

Just saw on the TV a Japanese inventor that had an eight wheeled electric car (4 front drive wheels and 4 rear drive wheels - both in tandem) and each wheel had a 100hp motor on it for 800hp. The thing would do 235mph and accelerate very well.

100hp per wheel would be great for a truck and get rid of all the weight of the trans, diffs & transfer case. It still might be a wash for the weight of the genset and motors, but i would think much more reliable. And maybe more efficient.

bhaugen

Hydraulics are a very Poor means of Transfering power. Like stated earlier you have a Pump and motor efficiency which a Good pump is going to be around 90% or less. Now couple that with a motor at 90% and don't forget to add in the heat loss (all that heat you feel from a hyd system is Hp loss) and the Hydraulic line/hose friction loss. Now you need to have some form of controlling the flow/pressure of the oil, that is a killer to eff. When I was in School for Ag Engineering the total Engine to ground eff% was around 60-65%on a hydrostatic tractor and 80-85% on a mechanical drive tractor. That is why the IH hydro tractors never took off. It took 20% Hp to do the same work, and they were hotter than blazes to use in the summer.

This is the same basic priciple on why a Manual trans gets better fuel economy compared to an auto. In the auto you are pumping "hydraulic fluid" to operate the transmission, and having to dissapate that heat in a Cooler.

MTGunNut

weight would be the killer me thinks.