Gas-Electric propulsion system for 3.5 ton conversion van

[H-Man]

I second dumping the slush box and putting in a junkyard manual. Where will you tag this? We can't do much to the engine and still pass California smog's visual component.

I'd chase aeromods because although the engine may be an issue, you can't fail the smog test for an airdam.

[cRiPpLe_rOoStEr]

A wide-ratio manual transmission improves the mileage considerably.

[MobilOne]

My '71 Dodge Polara 318 2 door hard top probably weighed nearly what your van weighs. It got 15 mpg at 50 mph, at 70 mph, and pulling a trailer or not. Get tbi or a modern carb and a lock up converter or a manual and get to 15 mpg+. If wood burners were so great, the Germans would still be using them (as they did during and after WWII).

[debit.servus]

Originally Posted by 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.

The van weighs in at 4 tons with all the stuff that is inside, and is a high-top, plus has thick knobby tires on two wheels (replacing tires every 6 months negates any fuel savings).

Perhaps use 2 of the HFT gensets? Would use 120 or 240v (depending on cost of buckboost converter) AC motor(s) to prevent the need for wires the size of my arm. Aren't monster size 120v AC motors more common than DC motors, and cheaper? Plus the HFT gensets alternator puts out straight AC power, so no DC to AC conversion losses.

Didn't know about those EV motor restriction mechanisms.

Originally Posted by freebeard

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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:


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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.

The detuned engine would be left in place, with the rest of the existing drivetrain. Perhaps only use the detuned engine for going up mountains so the system can be downsized.

An inline motor like that must cost thousands!

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

Wouldn't that 6 speed tall gear transmission and multipoint fuel injection cost thousands?

[debit.servus]

Originally Posted by Ecky

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

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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:

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^ 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.

What I like about this gas-electric system is it can be transferred over to another car, in a day.

Thank you for the calculations! 24mpg from a 20kw gasoline genset is swallowable.

What would be the price range for a low end 20kw gas-electric traction system, including 25 HP motor, sufficient motor controller and genset(s)? I guess it's too much because I'm asking...

The pusher trailer is a very smart idea, since it's not a good idea to hypercustomize the drivetrain on this rig; due to my income. A pusher trailer with an ultraefficient engine, trans, and power axles that pushes the van 100% would be traction for life, as the pusher trailer can be swapped into a different rig like a trailer is hooked to a different car/truck. Are pusher trailers legal? Of course I would mod the signals, power brakes, power steering, and anything else legally required to be operational when the car is moving to run with the detuned engine off.

Wouldn't swapping a gas engine for a diesel require modifying the fuel system, belts, pulleys, fuel pump, and everything that interfaces with the engine? Then theres the electrical! It's more than just "drop in", getting sick of people making these kinds of changes sound so easy. Unless there is some 5.2L 318 diesel with all relevant orifices in the same place as the stock engine, same for that tall-gear manual transmission; it will means rerouting every system.

Here is a discussion I found on the internet on improving fuel economy in 1986 dodge vans: m dodgeforum com>forum>showthread.php?t=289541&styleid=9

Originally Posted by cRiPpLe_rOoStEr

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

How?

[oldtamiyaphile]

As long as you have an auto trans the engine will have to be idling while in motion. Pusher trailer, genset, whatever, isn't going to help much, you're going to be idling a 318 just to lube the trans, turn over the power steering and provide brake vacuum. I can hardly think of a less efficient set up.

Start with aero, E-Fans and an electric power steering set up. You can then add a manual conversion and finally you'll be ready for some of your ideas.

If it were me, I'd buy a Prius (etc) and build a ~800lbs teardrop camper trailer (you'd still have an enclosed space with proper mattress and a usable kitchen). Modern cars tend to need less servicing, not more.

If your van weighs 4 ton I don't think you'll ever meet your target. At around 2.3 tons with a 1.6 EFI engine and 5 speed, my 2014 EMMA+Trailer only manages low 20's (this combo cruises very close to BSFC).

Even my 2 ton six speed TDi van only managed high 20's, much better aero at only 0.33 vs the .40+ of the Dodge.

[oil pan 4]

If you have the stock fuel system then you have the carter thermoquad carb.
I am used to old dodges with the thermoquad run so rich they roll coal.
Why not swap it out for something you can tune like an edelbrock 650, advanced tuning kit and an air/fuel ratio meter?

When a lifted up ram charger with 318, 4.1 gear and 727 transmission can get 12 to 13mpg by some one obsessed with keeping everything stock, to include the junk thermoquad carb you should be able to do a lot better than 7mpg.

If you want better fuel mileage there really isn't any point in modifying anything until you get it running correctly.

[debit.servus]

Originally Posted by oldtamiyaphile

As long as you have an auto trans the engine will have to be idling while in motion. Pusher trailer, genset, whatever, isn't going to help much, you're going to be idling a 318 just to lube the trans, turn over the power steering and provide brake vacuum. I can hardly think of a less efficient set up.

Start with aero, E-Fans and an electric power steering set up. You can then add a manual conversion and finally you'll be ready for some of your ideas.

If it were me, I'd buy a Prius (etc) and build a ~800lbs teardrop camper trailer (you'd still have an enclosed space with proper mattress and a usable kitchen). Modern cars tend to need less servicing, not more.
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Could the trans be put in in neutral and have the van roll like it's being towed? Couldn't the brake vaccumm and power steer be supplied by equipment powered by the genset?

There is no money for a Prius and teardrop trailer, plus they'll be fried when the EMP happens. Didn't you read the first post? Modern cars might need less servicing, but that servicing costs A LOT more as the parts are hyperspecialized and labor to install the parts is too.

My parents 2012 DODGE Caravan costs big bucks to keep looking and running like new. The plastic composite bumper got fendered, the replacement bumper cost about $550 and the labor was over $1000, plus cost of a rental car while the van was in the shop. The oil pan was smashed in by a large rock with other undercarrage damage while racing up a patch of muddy dirt road. Cost: About $750, plus $280 rental car to get back to San Jose, then $84 AMTRAK fare to go up to redding to pick the van up, with $8 taxi fare to go to the repair shop at 4 in the morning, and theres still more bodywork to be done.

New cars cost multiples more to fix when things go bust, plus there more new things in new cars with each new model year.

So if/when that new Prius has a mechanical problem that isn't covered by the warranty, have that high-limit credit card ready as the fix has a 4-figure price tag! Good luck in the plains of Wyoming when the computer decides to brick itself, warranting a 200+ mile tow to the nearest TOYOTA dealership; as the dealer is the exclusive mechanic for some of the newest cars! And forget about riding through the inevitable EMP and socio-economic collapse with your computer on wheels. This is why we don't see a lot of Priuses or other high-tech hybrids out in the country.

High-tech usually means high-maintence and high-cost. Rather have an less efficient low-tech drivetrain than an ultra-efficient high-tech drivetrain.

In many cases, older cars can be jerry-rigged and limped back to civilization if required. In many cases, Newer cars can't.

Originally Posted by oil pan 4

If you have the stock fuel system then you have the carter thermoquad carb.
I am used to old dodges with the thermoquad run so rich they roll coal.
Why not swap it out for something you can tune like an edelbrock 650, advanced tuning kit and an air/fuel ratio meter?

When a lifted up ram charger with 318, 4.1 gear and 727 transmission can get 12 to 13mpg by some one obsessed with keeping everything stock, to include the junk thermoquad carb you should be able to do a lot better than 7mpg.

If you want better fuel mileage there really isn't any point in modifying anything until you get it running correctly.

The carb is a HOLLY 2280 2-barrel carb. I looked at racing carbs and fuel injection conversion kits and hybrids of the two costing thousands. Any engine/trans/drivetrain swaps need to be in the low hundreds to be attainable.

Like the 24MPG estimate from a gas-electric traction system, 24MPG highway is even better than my parents 2012 DODGE Caravan minivan! Let's be realistic and say 21 MPG, accounting for all inefficiencies in the motors and controller. Why sip gas on a sore ass when it's possible to sip gas on a pampered ass? Can I have an estimate for the motor and controller, new & estimate for used? Any sources for cheap operational motors & controllers? Very good at perusing bargains on craigslist.

So it's possible to triple or even quadruple the MPG on this rig on a shoestring budget (less than $1000 for all mods)?

[oldtamiyaphile]

Originally Posted by debit.servus

Could the trans be put in in neutral and have the van roll like it's being towed? Couldn't the brake vaccumm and power steer be supplied by equipment powered by the genset?

There is no money for a Prius and teardrop trailer, plus they'll be fried when the EMP happens. Didn't you read the first post? Modern cars might need less servicing, but that servicing costs A LOT more as the parts are hyperspecialized and labor to install the parts is too.

Can your van be flat towed? If so it's often at low speed and short distances. A vacuum pump is a fairly easy thing to add, power steer less off the genset less so.

Frankly, a Prius ($5k) and DIY camper trailer ($2k) is going to cost you a lot less than this project, once you factor in the fuel savings. Servicing a Prius at the local dealer costs $140, at a time when most charge $350-400, generally rock solid reliability and super easy to work on too. If you know when the EMP is coming you could just sell before then. 50+ MPG (vs 10-15) buys a lot of servicing and parts.

I'm not convinced that using a genset to make electricity to power motors will make your van efficient. How will the vehicle accelerate? It's all well and good to calculate 18Kw needed to cruise at 55, but you'll need probably double that to have any acceleration let alone dealing with hills. Will the controller be able to run directly off the unfiltered genset? Will you actually need batteries so that the slightest incline or acceleration doesn't trip the safety systems? At the very least you'll need a ~40kwh genset to handle hills and headwinds. If you build the system just for flat road 55mph cruising you'll only be getting that theoretical 24mpg for a smaller amount of time.

Start with getting what you have now working efficiently, with an eye for future possible hybridisation. That's why I'd start with power steer, power brakes and making the thing capable of EOC, you'll need that stuff down the line anyway. Same with other tried and tested aeromods, E-Fans etc. You'll still benefit from them down the line.

[freebeard]

So it's possible to triple or even quadruple the MPG on this rig on...(less than $1000 for all mods)?

No.

Out of tune is not detuned. There goes half the budget right there. The low-cost stuff is hypermiling and aerodynamics. With those three you can surely double the mileage.

To triple it would require every trick in the book—alternator delete, LED lights, aerospace coatings and lubricants on all moving parts, low rolling resistance tires — and a full boat tail.

Quadruple? 30mpg? You tell us, we'd all love to hear the plan.