CNG fueling systems

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I wanted to get the ball rolling about CNG technology.Diesels have Greasel and BioDiesel,spark plugs have options too.
 
My brother is on his second CNG car. The first one was a Ford Crown Vic and the current one is a Honda Civic. The original motivation for CNG was the ability to drive solo in HOV lanes here in CA.

CNG is simple technology compared to hybrids, pure electrics or even modern turbodiesels. The engines are standard EFI gasoline engines with minimal changes. Fiberglass pressure tanks hold the fuel at 3000psi.

Advantages:

The engine runs so clean that the tailpipe looks like the engine has never been started.

Fuel costs per equivalent gallon of gasoline is about $1 less.

Refuelling takes no longer and is no more difficult for the driver than filling a gasoline car.

Disadvantages:

No trunk space in the Civic because the tanks are so bulky. The Crown Vic had more room.

No range. 6-8 equivalent gallons is all the Civic holds, even with the tanks taking up all available space.

The fuel gauge is almost worthless. Since CNG is not a liquid, there is no fuel level, only pressure.

It is only usable in big urban areas, since refuelling stations are so rare. A trip to Las Vegas is out of the question. You need another car for long trips, the same disadvantage as pure electrics.
 
I wanted to bump this thread back up to see if I can't learn more about CNG systems myself too.

Just to add what Jimbo said, CNG like propane, both do burn very clean which arrises a question for me, do you still need to change oil in a CNG system? I'd like to learn as much as possible about CNG's and I'm sure others would too,,,,,AR
 
quote:

Originally posted by Jimbo:

No range. 6-8 equivalent gallons is all the Civic holds, even with the tanks taking up all available space.

The fuel gauge is almost worthless. Since CNG is not a liquid, there is no fuel level, only pressure.

It is only usable in big urban areas, since refuelling stations are so rare. A trip to Las Vegas is out of the question. You need another car for long trips, the same disadvantage as pure electrics.


I was doing some research and stumbled across this site that rent NGV vehicles. Check out the specs on this Honda Civic,,,,,,AR

http://www.evrental.com/civicgx.html
 
Reading on this website http://www.eere.energy.gov/cleancities/blends/hcng.html this showes that vehicles using HCNG (Hydrogen/Natural Gas) takes down NOx and CO levels down lower than that of just CNG systems. If you look at the graph, HCNG took down NOx levels in half!

I am in no way bashing CNG systems. I think there a perfect idea. I am just simply comparing. Also, according to the website, it states you have to change oil around 10-12,000 miles. A conventionally fueled vehicle with dino oil and LC will do the same thing. Which is cheaper in the long run as far as OCI's are? I dunno, I'm too lazy to do the math, lol Just thought I would share some knowledge I gained,,,,,,AR
 
After hearing a little bit of an interview with T. Boone Pickens, the Texas oilman who has predicted the current prices and problems with oil, I began wondering about a CNG conversion from regular gasoline. Does anyone know if this can be done at a reasonable price? I know that there used to be places that did this back in the 70s. My idea is to convert my Prius to CNG with a home refueling station. Seems like a winner to me with the already great efficiency of the Prius, and I have read that engines last forever with CNG because it is so clean.
 
I am still intrigued by CNG systems and I would like to learn as much as I can about them and there maintence requirements.

pa04prius- Usually a conversion system ranges from 2-3000 big ones. Your plan does sound like a winner but figure how big of a tank would you need for refueling your car and cost. I would imagine every so often, the nearby gas company or someone comes by and refils your tank?? I also agree with the fact that a given engine would run a very long time with routine maintence because of it's cleanliness. If you convert your car, please keep us up to date on it and how your car is running,,,AR
 
Ok question. If CNG is such a dry gas and lacks lubricity to the parts in the engine, then why does equipment last so much longer besides CNG is a clean burning gas?

Take Impco for instance, they manufacture engines with the CNG kits on them already. My main question is are the metal(s) inside the engines made of something to withstand the lack of lubricity? Thanks,,,AR
 
quote:

Originally posted by Airborne Ranger:
I am still intrigued by CNG systems and I would like to learn as much as I can about them and there maintence requirements.

pa04prius- Usually a conversion system ranges from 2-3000 big ones. Your plan does sound like a winner but figure how big of a tank would you need for refueling your car and cost. I would imagine every so often, the nearby gas company or someone comes by and refils your tank??


One of the difficulties with working with CNG is that it is stored at 3,000 to 5,000 psi. You probably wouldn't want a big storage tank at home and it would be difficult to get someone to fill it if you had one.

I think you would either need to use existing CNG filling stations or put in a pumping system at home to fill your car from your home natural gas line.

Natural gas prices are also somewhat responsive to oil prices, so expect them to climb if the price of oil climbs. The should still be quite a bit less than gas.

Multiply the price per therm (100k BTU) of NG by 1.15 to figure out what a gallon of gasoline equivilant energy using NG would cost.
 
Home filling stations use a small garbage pail sized "pump" that is typically an overnight re-fill, compared to the 5 minutes it might take at a filling station.
Commercial fill stations are not much different from a standard gas pump, just the nozzle is a coupler.
All our work vehicles are dual fuel cng/gasoline (prior to ~1988 it was propane/gasoline) conversion costs ~4000cdn from scratch (tanks, lines, regulators, cng computer/controller, installation). Unless you do a lot of miles per year, it will take a few years to recoup the costs of conversion.
Range will be your biggest draw back but dual fuel alleviates any concerns about getting stranded. A pair of 16x32" tanks get me anywhere from 70-100 miles, and at current prices its $15 to refill at the commercial station. As with propane, the biggest tanks and the most tanks you can fit, the better.
Oil does stay clean for an entire OCI, and I would be curious what an analysis would show, but we in general do oil changes every 3 months regardless of mileage. Incidently the oil life monitor on my new Express came on for the first time at 7900km (4908miles).

As with propane, if you run a dedicated system you can push up the compression a bit and get rid of the slight power loss compared to gasoline operation... And heres my beef with ford, they just dropped a cng system onto a regular gas engine. They could have probably sold a lot more units if they also provided a slightly hopped up engine to go with the cng option (which also only came with 2.73 gears).

Personally, I have no beefs at all with cng or propane. If it would be cost effective I'd convert my vehicles over.

Alex.
 
cng is similar to propane run engines in respect to the "dry gas"part. cng is better. There isn't anything that gets lubed by the gas other than the valves and the valve seats. Which is lubes by the lead in leaded gas or some other additive. Since the removal of lead in gas" Good for lots of reasons" hardened valve seats or induction hardening has been used. The main reasons for increased engine life is, no wash down of the cylinder walls with wet gas and there is less if any feul dilution in the crancase oil.
 
You can often find a Honda GX (cng) for sale on ebay. Biggest drawback for CNG is finding a place to fuel up. Interesting: the exhaust from the Honda GX can actually be cleaner than the air going into the intake. I forget the spec, but Honda GX is the only one that meets it. Search "CNG" on ebay motors for the GX and F150s too.

Propane is the most widely available alternative fuel. I live in a small town of 3000 and we have a propane station here. Propane is not as clean as CNG but is easier to find.

I drove in CNG pickups when I was in the army. They were civilian chevy 1/2 ton w/ CNG tanks instead of gas tanks. They had more power than the gasoline version. I guess that is because they have no smog equipment. In the winter, you would get a huge, white plume of water vapor (smoke/steam) out of the tailpipe for a while--until it warmed up.

I'd go with CNG in a minute if I had a fuel station around me.
 
quote:

Originally posted by MAJA:
Heres an interesting idea, from Honda no less. So, it must be a good idea.

http://www.autofieldguide.com/dp/auto/newsmonger.cfm?id=969


That is handy. I am currently using a CNG/gasoline dual fuel pickup this week at work. I have used it several times before. It takes up some bed space but it extends the range of the truck considerably. I run the CNG until I run out (200-300 miles depending on conditions, the tanks take half the bed))and then switch to gasoline. The vehicle is easy to fuel the only caution Is to run a tank of gasoline every 60 days to keep that system in good working order. The system isn't perfect. The idle is alittle rougher but it seems to work fine at cruise.

I would add a kit to my personal Tacoma if it were economicaly feasable and available. to do the conversion and have a home fueling station. Just for the range it adds.

[ August 23, 2005, 04:41 AM: Message edited by: Bryanccfshr ]
 
I too am interested in a CNG conversion kit with home CNG refueling setup. Where can such a kit be purchased? I have searched quite a bit, but all the hits are usually for kits/conversions in India and Pakistan.

The only place I found that looked like it might have something available was Mogas Fuel Systems in British Columbia. Some of there systems I guess have some sort of link into the ODBII of the engine computer for fuel strategy.

I realize refilling at home will take overnight; that's fine with me. I'd like to stay bifuel if possible for more flexibility.

Any sources for tanks and a home refilling setup?

-Louis
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