Datsun 240z becomes Electric/Diesel Hybrid

[AmpEater]

Thanks for all the kinds words guys. I'm incredibly excited about this project, pretty much been obesssing over it for months. The only reason I've got time to post anything is because I'm stuck waiting for the transmission/motor adapter to arrive and can't weld the battery trays until the motor is in place, can't finish wiring until I know exactly where the batteries are going to go, etc, etc. As soon as this is hear its going to be a non-stop-work-a-thon which will (hopefully) conclude with the car moving out of the garage on electric power.

The generator is going to probably be the real challenge. I'm starting with a 10hp air-cooled single cylinder engine and hope to get 16+hp peak, 14 cont and "clean" emissions. I know that the propane (or onboard hydrogen) will help particulates alot, but I don't know if this will be enough to get anywhere near a catalytic-equipped gasoline car. Does anyone know if they even make catalytic converters that will work for small engines? For diesels? Or would I be better off with a lpg engine emission wise?

[RH77]

Originally Posted by AmpEater

Does anyone know if they even make catalytic converters that will work for small engines? For diesels? Or would I be better off with a lpg engine emission wise?

LPG / LNG is cleaner emission-wise, but consumption is higher and availability is limited. Here's the Wiki entry on Diesel Catalytic Converters...

I'm sure that they're readily available for purchase and most likely can be adapted for your application. The problem with the Diesel/Hybrid is keeping the catalyst consistently heated for proper operation, if starting/shutdown is frequent.

LNG/LPG would require specialized tanks as well. I would look to see if these fuels are locally available for you and go from there...

RH77

[tjts1]

How much more fuel efficient do you think a diesel generator will be compared to an off the shelf gas generator from honda for example? It seems like a lot of work for not much gain. Usually gas generators that are run at constant speed and max load are darn near as efficient as a diesel. Don't take it the wrong way, I think you have an excellent concept in mind. I just think an off the shelf generator is worth a second look. I'm sure you've already done that. I don't know if 6.7hp is large enough but it seems to be the most bang for the buck and weight. They go all the way up to 14.7hp
http://www.hondapowerequipment.com/M...delName=eg5000
Used generators are dirt cheap on Craigslist.
cheers
Justin

[diesel_john]

welcome to the site AmpEater. I have dreamed about doing a project like yours. You are doing great. My 2 cents worth may be not be worth 2 cents.
So ignore me, if your past this point. A direct coupled (shaft to shaft) engine to gen. would be considerably more efficient than belt driven. Is it possible to run the engine at it's most efficient RPM or do you need a certain frequency. A much smaller engine could be programed to shut down after you park at your destination on long trips. When leaving home base, the gen. could be started early on if the trip is to be long. I am a diesel fanatic but diesels are a challenge to isolate. (vibration and sound). Air rides, internal balance shafts, big intake and exhaust mufflers. The smallest single cylinder that will keep the batteries up would be good. I have driven 500 miles without stopping but I would have been safer if I had stopped every couple hours for a stretch. And let my "batteries charge". I would be tempted to try a little tiny, smooth, quiet off the shelf generator first to see how the duty cycles work out. Do not know if any little gensets will burn E85. Direct injected flex fuel engines will compete with diesels. You can quote me on that.
The price of diesel on the road has lost its advantage.
10 % winter to 20 % summer biodiesel blends do burn considerably cleaner in my engine, than straight low sulfur, and no heater. Electricity may or may not be a renewal fuel but B100 argueably is.
Is there any way to run a shaft out the back of the motor or transmission, or differential to direct couple a generator for regen. capability. Or a motor/generator all in one. The big advantage of batteries is the regen. capability. On the transmission, the direct drive gear is the most efficient not fifth. Although the ability to down shift might be great for regen. After your drive train is running, if you add aero modds your not going to need as much power as you think. Again my thoughts are meant only as encouragement.

[AmpEater]

To keep things organized I will try to respond to each post/point seperately.

MetroMPG - I had not seen that, very cool. I am a little bummed I wont be the first to complete such a project, but its almost strange that you don't see more projects like this because all the hardware is available "off-the-shelf" and its just a matter of putting it all together.

RH77 - Thanks for that link, I hadn't found that yet. You touched on an important point with the lpg - availability. I'd like to have the ability to take longer trips with this thing, and I don't want to have a massive fuel tank taking up precious space. That pretty much limits my options to diesel, and gas.

tjts1 - I hadn't really considered an off the shelf generator, though that would make things alot easier. My main reason for choosing diesel is the higher efficiency at turning fuel btu's into kw (do to lack of a throttle body for one). But my logic may have been flawed if each engine is running at WOT (minimal pumping losses) as a generator would be. Diesel does have the option of running off of straight vegetable oil. I am trying to keep my design as modular as possible so if this diesel/gen combo doesn't live up to my expectations I could always swap it out for a gas unit with minimal fuss. I do need around 10,000w continous (for 65mph cruising) and any normal generator of this size is going to be bigger and more expensive than I would like (my belt driven 10,000watt home made gen is about $800 total)

diesel_john - You make a good point about the direct coupled efficiency gain, I hadn't considered that. I bought a belt unit because it seemed like mounting would be much easier with a belt length that could be adjusted until everything fit in the rear nicely. The fact that diesel price has spiked recently is a bummer, the choice would be much easier if it were stil cheaper. As you probably know, a gallon of diesel contains more energy so this may make up for the price difference. As far as regen goes, my motor actually has interpoles already, which allows it to be used as a generator without arcing to death like a normal series wound would during regen. The main limitation is the motor controller. Mine does not support it, but if I'm willing to live with 1/2 the amp rating (500A peak) I could get a 144v controller with regen capability. I really, really want regen so I might make the swap at some point if it seems like 500A will be enough for decent acceleration. I suppose a generator in parallel with the motor would give me the same capability without the power sacrifice, at the expense of 100lbs. SO many possibilities....

[bennelson]

Very cool project!

Keep up the good work!

[roflwaffle]

Since you'll be running it to charge the batteries, the only difference between a gas and diesel genset is that the diesel will likely cost more, be heavier, and pollute more. A gas engine on LNG/LPG would probably be the cleanest option given the on/off nature of the generator, but the Lambda must be around 1.6-8 for optimal emissions based on what I've read. Gasoline engines would likely be a pain emissions wise since the cat would have to be lit off every time, which would really increase emissions.

[AmpEater]

Originally Posted by roflwaffle

Since you'll be running it to charge the batteries, the only difference between a gas and diesel genset is that the diesel will likely cost more, be heavier, and pollute more. A gas engine on LNG/LPG would probably be the cleanest option given the on/off nature of the generator, but the Lambda must be around 1.6-8 for optimal emissions based on what I've read. Gasoline engines would likely be a pain emissions wise since the cat would have to be lit off every time, which would really increase emissions.

I really only intend to use the generator for perhaps 30min a day, split into 2 sessions. And then occasionally for 2-3hours. And I don't really expect to use it to "charge the batteries" so much as I want the generator to augment their output just as much as is necessary to get me where I'm going at a reasonable dod. I plan to recharge at school, and work, in addition to home and therefore still be running the car on 80% recharged stored electrons and 20% diesel electrons at any given time.

I regret having just commited to purchasing a diesel engine. But, this is basically a rolling science project for the next couple months and swaping over to propane would be a pretty simple matter. I've changed the battery mounting scheme to leave alot more space for the generator "pod" and therefore have room for an LPG tank if necessay.

Converting a gasoline engine to run of propane is not too complex it seems, with the possiblity of even leaving the gasoline equipment functional should it be necessary. Since I expect the generator to be running at constant speed, constant load finding the optimal amount of propane to inject for a good burn should be simple with a wideband O2 sensor (which I happen to have). I will have to explore this option.

Any ideas on how the emissions of a propane injected diesel compare? If the presence of lpg in the combustion chamber really creates a faster, more effecient burn with drastically reduced particulate emissions then I suspect a diesel may be comparably "green". I will have to find a way to test this.

[bennelson]

I think diesel is much BETTER for a rolling science project. That leaves open experimentation with Bio-diesel and waste vegetable oil!

[AmpEater]

"I think diesel is much BETTER for a rolling science project. That leaves open experimentation with Bio-diesel and waste vegetable oil!"

Kind of that I was thinking too. I also want to experiment with turbo/supercharging to increase my hp/lb and therefore kw/lb and also increase total efficiency by reducing pumping losses. A supercharged propane injected waste vegetable oil buring engine just has a nice ring to it. And I am much more apt to experiment with something that could be swapped out any any time for a different engine.

I've also been very interested in biogas recently, made from anaerobically digested waste. This could be used just like natural gas/propane, but at a higher rate due to a lower btu/lb content. The problem then becomes compressing it safely, probably at pretty low pressures, which means low range (but on 100% recycled carbon fuels). This is kind of off topic for now though, since I've committed to the diesel already. Should be here in about 5 days.