Gas-Electric propulsion system for 3.5 ton conversion van

[debit.servus]

Hellow, brand new here.
My name is Paul, a poor boy with a 1986 Dodge B250 conversion van. Bigger than an SUV but can be lived in with most of the comforts of a conventional house or high class RV. I have been fitting the interior for 2 years for comfortable full-time living. The van gets me places, mostly without issue; had four 1000 mile road trips with it without any major breakdowns. Love cars from this era because the systems are user-servicable unlike most new cars. There are no electronics in this van to fry in an EMP event or not be supported by the automaker 5 model years down the road.

The van does has it's fair share of quirks for it's age. The engine compression is off, the carb is detuned and running rich, engine is running very poorly and inefficiently; but what's important is the van does get me places at 7.7 MPG. There is not a penny for another van or financing for a ultra-fuel-efficient van, so I need to make this one work out.

People keep saying how I should get a small car and camp it in while exploring the US and Canada, to save on gas. I don't believe in sipping gas on a sore ass, sleeping crooked in the back of a minivan or Prius; freezing in the dark and sweating in the heat to be able to fuel thousands of miles on a four figure income. At the same time I don't believe in travelling in a 50 foot land yacht complete with satellite TV, treadmill and wine cooler. Asking for 1-2 levels above where I'm at here.

If I did all the efficiency mods and tuned up the engine, and overall drivetrain; it would probably result in a less than double the MPG. Even with 14 MPG highway I still can't afford to travel thousands of miles on gasoline. Triple the MPG and it becomes swallowable.

One underunity fuel I am ready to build the system for is Wood Gasification, a refinery looking system that cooks wood into a gas that the engine can burn. After doing my research and feasability study, the cost-per-mile is significantly cheaper than gasoline; accounting all time and money costs including the wood gathering, processing and cost to maintain a broom closet size system.

The other underunity fuel system is a "Gas-Electric" traction system like how diesel electric locomotives runs. What I am envisioning is a large generator, which powers a 120v AC electric motor (or array of motors depending on cost), somehow connected to drive the propellor shaft after the transmission and before the differential. The motor(s) would be controlled by a low-tech pedal controller (like the speed pedal for electric sewing machine) directly or more likely relayed from the pedal controller due to the high current demand of the motor(s).

The idea here is to avoid using the vans detuned and inefficient engine by adding a low-tech gas-electric traction system, and take advantage of the efficiencies of electric power.

(viamotors com>vehicles>electric-van)VIA Motors Introduces First Extended-Range Electric Van[/url] This work van hybrid has a range extension engine, which kicks in after the batteries are dead. They say their van gets 33 MPG highway from their range extension engine and propreitary EV system. The system I am envisioning is like that sans batteries, and using low-cost & off-the-shelf components everywhere.
The system I am envisioning would be like the poor mans VIA Motors van without the batteries.

The whole system needs to be as low-tech, low-cost, modular and "how-swappable" as possible. Hot-swappable means a burnt out or unwound motor can be changed on the side of the road, same for all other components. Would prefer to keep the whole initial cost under $2000.

The same idea is applied in diesel electric locomotives the world over. Here it's scaled down, the electricity comes from a gasoline generator, and the motor(s) propel a 3.5 ton extended high-top van.

To get a grasp on the feasability and cost-effectiveness of my gas-electric propulsion system, a few questions to ask are:
-How many watt-hours are required to move a ton of weight 1 mile?
-How many HP does the traction motor(s) need to be to get a ton of weight to a speed of at least 50 MPH on flat interstate? How much HP to maintain the speed? How many watts per electric HP?
-The running watts the gasoline generator need to provide to power the electric motor(s), which propels the van at 50 MPH on flat interstate (speed of 50 MPH on flat interstate is a minimum system requirement)?
-Most Importantly: What would the equivalent MPG (eMPG) look like? I believe to calculate the eMPG, take the miles travelled in one hour and divide by the fuel-use-per-hour of the electric generator supplying power to the electric traction motor(s). I believe eMPG could be at least double or triple 7.7 MPG.

For those still unsure of what I am describing:
[gasoline generator]->[some kind of motor controller]->[giant traction motor(s) using some system to mechanically transmit energy to the propeller shaft between transmission and differential]->[The van and me going places of distance at considerably higher MPG compared to running the vans detuned, inefficient carburated V8 engine, in comfort and style].

[oil pan 4]

I doubled the fuel mileage in my suburban with 7.4L engine by tuning the carb for lean burn cruse and doing EOC. It started out getting 6.6mpg, it was so horrible I only collected data for roughly two 50 mile fillups.
Just the lean burn increased economy about 50% or up to 10mpg.
I was told that double digit fuel economy with a 3 speed auto and big block would not happen, then when I started doing EOC it went up to 12 to 13 mpg.
I have not taken the suburban on any highway trips, the only highway trip data I have is filling up, driving to the next town over then back, about 50 miles and filling up again at the same gas pump pointed in the same direction. Highway fuel mileage is between 16 and 20 mpg with lean burn.

To move a much smaller electric truck like an S-10 or ranger at 50mph, best case scenario is 7,000 to 10,000 watts to maintain speed.
To move a large vehicle like that van, more like 20 kw.

As far as budget a half way decent 7 to 8 kw generator is going to cost almost $1,000.
A good generator intended to run at full load for many hours will cost at least double that and provide less power.

Lets put it this way, if I thought it could be done for $2,000 to $3,000 I would have already done it.

[elhigh]

I admire your imagination but I think you're pushing at the wrong potentials.

I used to drive a 1990 Dodge B350 Wagon, the 15-passenger van, about a half-generation newer than yours. It never got worse than 10mpg, and it never got better than 15mpg. I was doing almost exclusively city miles, so never going below 10 was pretty good. Mine had TBI on the massive 360 V8 and a four-speed OD auto.

You didn't tell us what engine you have. For your sake I hope it's the 318 (5.2). The depth of knowledge from all sorts of gearheads for the 318 is enormous. The range of go-fast and go-long parts for the 318 is stunning. The flexibility of aftermarket modifications is fabulous.

You could convert your existing ride into a surprisingly thrifty cruiser. Believe it or not there is such a thing as a four-speed manual available for that van. Spend some time nailing down a good, reliable tune on the carb or convert it to a good TBI, perhaps with a lean burn mode, and I bet you could knock out 20mpg all day long at modest let's-go-see-America speeds.

If you are absolutely determined to go the hybrid route, don't mess with the drivetrain. There's a yawning abyss of space under the B-series, fab up racks and install batteries, and build a pusher trailer like Mr. Sharkey. Bolt a rack of solar panels to the roof and the battery pack powers your occasional boost and also your comfort loads, lighting and whatnot.

NOTE: Mr. Sharkey's pusher trailer was, in fact, a diesel VW Rabbit nose that would push his EV on long trips. In retrospect if you wanted to make your van into an EV and have a diesel for cruising, that's a concept worth exploring too. In any case you could aerodynamically couple the trailer to the van, and it would contribute a net gain on your fuel economy even when it wasn't pushing, in addition to allowing you to move some storage out of the main vehicle.

The wood gas solution is a little wiggy in my opinion. I think those gasifiers are finicky and hard to manage. That's just me, your mileage may vary. But for the money you could spend building one and adapting your existing engine to it, you could just as easily make your existing engine into a really, really good modern engine that was affordable, supported in the existing infrastructure for fuel and parts, and wouldn't get you pulled over because it looked like your trailer was on fire.

[Ecky]

I expect dropping in a more efficient, modern drivetrain would be a cheaper and better alternative to a gasoline-electric system, too.

A best-case scenario would probably be to find a small diesel that you can bolt onto your existing transmission, and if you're feeling particularly adventurous, an auto -> manual conversion with taller gearing.

[debit.servus]

Originally Posted by elhigh

I admire your imagination but I think you're pushing at the wrong potentials.
...

You didn't tell us what engine you have. For your sake I hope it's the 318 (5.2). The depth of knowledge from all sorts of gearheads for the 318 is enormous. The range of go-fast and go-long parts for the 318 is stunning. The flexibility of aftermarket modifications is fabulous.

...

NOTE: Mr. Sharkey's pusher trailer was, in fact, a diesel VW Rabbit nose that would push his EV on long trips. In retrospect if you wanted to make your van into an EV and have a diesel for cruising, that's a concept worth exploring too. In any case you could aerodynamically couple the trailer to the van, and it would contribute a net gain on your fuel economy even when it wasn't pushing, in addition to allowing you to move some storage out of the main vehicle.
...

How does a gas-electric drive system push at the wrong potentials? The generator I am looking at is harborfreight com>engines-generators>gas-engine-generators>13500-peak11000-running-watts-22-hp-670cc-gas-generator-epa-iii-61725.html . Yes I know it's a cheapie and won't put out clean power. Also, What price range is a low-end motor controller and traction motor to propel the van? Perhaps pick the motor(s) and controller out from a wrecked EV to lower cost?
The engine is a 5.2L 318 V8, very lucky to choose a van a common and cheap parts.

A pusher trailer was something I thought of as well, with an ultra-efficient engine on it to push the van 100%.

Originally Posted by Ecky

I expect dropping in a more efficient, modern drivetrain would be a cheaper and better alternative to a gasoline-electric system, too.

A best-case scenario would probably be to find a small diesel that you can bolt onto your existing transmission, and if you're feeling particularly adventurous, an auto -> manual conversion with taller gearing.

A new ultra-efficient drivetrain would cost more to upkeep than the fuel savings. This is why I can't afford a new car; the registration, insurance and maintence on newer cars cost waay more than on older cars.

Diesel has a more stable price than gas, meaning diesel see sales much less often than gas does. Once could stock up on gasoline when it's on sale and have lower running costs than diesel.

I noticed nobody answered any of the questions from my feasibility and cost effectiveness checklist. I need somebody to do the math to see if this gas-electric system has at least double to quadruple the eMPG?

[oil pan 4]

A 318 only getting 7mpg something has to be very wrong there. You should be able to just about double that mileage with a carb using a lean burn cruse tune.

I see a few problems with using that HF generator.
Over all it does not make enough power and generators like that are only rated to run continuously at about half load.
According to NEC they define "continuous" as anything more than 20 minutes for wiring. I find that even name brand generators commonly use under sized wiring for what their max power output is.

A new DC motor that could move that van would cost between $1,500 and $2,000 and a DC motor controller would cost at least several hundred.

A used EV drive might cost around the same and you would have to defeat all those OEM proprietary road blocks they install to keep people from using anything but manufacturer original parts in the vehicle or using the motor for anything but powering the vehicle it came in.

[Ecky]

Given that amount of power, my guess is that you'd top out around 40-45mph.

Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com

Plugging in some numbers I ballparked (4000lbs, 35 sqft frontal area, 0.45cd), you would need 23HP from the electric motor to maintain 55mph on a level grade, which is something like 18,000 watts.

Even without considering the electrical part of the system, at that point, you're getting into the price range where a new-to-you low miles gasoline or diesel engine will be less expensive and likely a lot more reliable.

I would however like to see something like this built.

~

Some back of the envelope calculations:

Let's be optimistic and assume 90% efficiency from your A/C motor (most EVs are DC, so I doubt you'll find one from a wrecked car). You'd need about 20kw to cruise at 55. I don't think you'll find too many in this size that run on gasoline, but let's assume you score a diesel one for not too terribly much:

Generac Power Systems | Home Standby Generators | Protector Series | 20kW | Generac Power Systems

^ The manual claims approximately 2 gallons per hour @ 100% load (55mph), which would put you in the ballpark of 27 miles per gallon on diesel.

If you can find a gasoline generator of this size, and assuming it's just as efficient, due to the reduced BTU content of gasoline vs diesel, you'd be closer to 24mpg - which is still a very attractive number in a vehicle that size.

However, I'm willing to bet you can get 24mpg with a drop-in diesel engine and some taller gearing, for a lot less than the cost of a 20kw generator + A/C motor + controller + fabricating mounting and drivetrain components.

[freebeard]

Hi. I don't think you need to sell the idea of living in a step van on the open road.

However, I do question the efficacy of your plan. Are you going to leave in place the de-tuned motor you already own when you replace it with an motor/generator expensive enough to have equal output? Plus a second electric unit?

How about this? From a 2009 Ecomodder thread:


http://ecomodder.com/forum/showthrea...tml#post124993

I'd never seen this 2009 thread before—I found it through Google Image Search. It came up first! It's an electric motor that inlines behind the transmission, like an overdrive. You'll want one that does regeneration. Then add a modest battery pack scavenged from a Leaf or something, add MPaulHolmes open-source controller and you'd have a KERS (Kinetic Energy Recovery System).

More here: https://www.google.com/search?q=inli...electric+motor

You have two posts so you're past the Introductions subforum stage. As soon as you have five posts you can post pictures.

I see you have a presence on the Drive On Wood! forum but I haven't looked at your posts there. Isn't there a lot of cleaning filters involved?

You can probably get to 10mpg on aerodynamics alone. There's a subforum for that.

[cRiPpLe_rOoStEr]

Any attempt to reinvent the wheel while keeping the unproperly-tuned V8 wouldn't worth the effort and the cost.

[JRMichler]

Any IC engine > generator > motor drive system is limited by the efficiency of the engine minus the inefficiency of converting power to electricity minus the inefficiency of converting the electricity back into mechanical power. Diesel electric drive systems are well suited for high power applications such as locomotives. Adding an engine generator and electric motor to your van would add a number of failure points.

Since you list mileage, simplicity, reliability, and repairability as priorities, I suggest rebuilding the engine you have and making the modifications suggested by earlier posters. I also suggest a mileage cam and a five or six speed manual transmission, paying particular attention to the final drive ratio in top gear.

I would put in a multi point fuel injection system. If you want the on the road repairability of a carburetor, keep the carburetor for the throttle. If the fuel injection gets fried on the road, switch the gas line back to the carburetor and keep going.

I would also cover the roof with solar panels and put in an appropriate number of deep cycle batteries. You should be able to eliminate the need to run the engine solely for charging batteries.

I believe that such a system would have better real world mileage than any Harbor Freight generator / motor system.