Hey all, I'm debating converting my 3.4 pushrod over to natural gas. I'm wondering if anyone else has done it? Is there any place that makes a tank specifically for the fiero? I pretty much use the car solely for commuting these days, so I'm not worried about finding a filling station (I can do that at home).

So if anyone has any info, or has done it, please post away!

-Thanks
(PS, if I do convert it, I'll be putting my nitrous express kit up for sale.)

The Mother Earth News had an article about converting to propane years ago (1972.) Not Fiero. I think finding a tank specifically for a Fiero would be a pipe dream. You could probably find something that would fit in the tunnel, tho, where the gas tank is. Something long and skinny.

The article was posted on the net, probably still is. Google propane conversion.

Yeah I saw that article.But it's more for a carburated vehicle. And I live in California so such a do it yourself approach is undoubtedly illegal. Looking for something that will pass muster at the smog nazis.

Just curious , How much is propane in your part of the country ? We had propane operated buses here for awhile ---I think they where re-tired do to cost and accidents.

maybe illegal in some places but I know there are propane powered vehicles in FL and all accross the south east. I know you will gain some power and a little economy but also this is propane/gas and not just propane. I know there is a willis truck with a chevy 350 on propane getting some awsome power and tourqe. But the cost of propane and how often you have to replace the tanks it is hand in hand with the price of gas. Now running a gas/propane kit where you can switch between the different fuels to add some mileage to the gimped fiero mileage.

I think the point was missed. He wants to convert to "Natural Gas" and that is Compressed Natural Gas or CNG. Propane powered vehicles is not the same.
Problem with propane is if you get a leak in an accident there will be a liquid fuel spill.
With CNG there is no liquid. If a leak occurs the gas will rise into the atmosphere and natural gas will not explode unless certain conditions are present,, ie. confined space.

To use CNG you need to compress it to 3000 psi in the proper tank. The tanks are super heavy whether made of steel or aluminum. You'll need to find a pumping station to fill the tank. The setups I'm familiar with have a dual switch to go back to gasoline on the fly.

Cruising range with CNG is not as good as an equal amount of gasoline. Your state may raise an eyebrow on the fact that your not paying road tax on CNG.

I dont think a Fiero would be a good candidate for CNG due to the weight of the tank(s) alone.
The aluminum tanks we used for pickup truck conversions took 2 strong guys to pick up "one".

I did this 15-20 years ago to a honda civic

we gutted the back seat and put in a aluminum 6 gallon tank

we then did a custom back to cover the tank so it appeared as a two seater with open flat rear area

I overhauled the engine and increased the compression upwards

the reason for the engine mod is because the natural gas has an equivalent octane rating of 120 ish as opposed to a maximun of 104 on gasoline.

all in all I was into it for about $2,000. I got government grants totaling about 900 so I was out of pocket about 1100

I was paying about 60% of gas price and I dyno'd the vehicle and I got about 80% power as compared to gasoline.

Mine was a duel fuel, I should have gone dedicated natural gas

All in all it was cheap to run, and with todays gas prices the spread is even greater

The major thing I did not like was that when you fueled up you were still paying for road taxes etc, if you could get your own residential compressor which will take several several hours to fill you could just tap into your home supply meter and get the natural gas extremely cheap.

Like I said I did this over 15 years ago to a 1981 honda civic. The aluminum tank is larger then steel I thing about 16" in dia as compared to the steel which was about 12-13" in dia and was about 36-42" wide.

The install was really simple and they put in an external bag cover and exhaust to the outside in the event of a leak as required by law. On the fiero I think they will allow you to have two 2" holes on the bottom, if you put it in the trunk.

Natural gas is lighter then air and wil rise where as propane is heavier and will sink.

All in all I liked it, lots of benifits, engine runs really clean, oil rarely gets dirty, easy starts and smooth idling, the only thing at the time I didn't like was the minimal difference between the cost of natural gas and gasoline, resulting in a very little cash savings.

To be realistic in pricing you should really consider that natural gas will only give you about 80% the thermal output as you will see in gasoline.

I understand they have come a long way with the installs now and they are extremely simple.

I also understand that this will then be considered as a dual fuel system thus you can use the high occupancy lanes in california even with one person as California is attempting to promote these type of vehicles.

Oh on the comment on strength, they are rated to 5000 psi with a working temperature of 3000. Different stations filled upwards to 3600, so when the fill cooled you were about 3200 psi. They test these things with high powered rifle rounds and even though the round will penetrate, they do not explode, you really have to see a natural gas tank construction to understand.

You can mix and match tanks and locations, you should be able to get a 5-6 gallon tank in the lower portion of the fiero with a 3-4 gallon up front. they connect the tanks by high pressure hose. You could then put the filler on the front tank.

The real expense was the tanks themselves, the rest were electronics and fuel connections.

I hopes this helps, you have a good idea here

Tim

Not sure about CNG but cars converted from gasoline to Propane must be periodically switched to gasoline. On the dual-fuel F150 I drive, one tank of gasoline per month is recommended. I usually run one until dry, switch to the other. Run that one almost dry then fill both and switch again.

Another problem here is that you have to get the emissions tested twice. And even though it (edit: the F150) is OBD-II, it has to go on the dyno. (edit: The normal OBD-II vehicle emission test here is a connector read but bi-fuel vehicles made before 2004 must be tested as non-OBD-II.)

[This message has been edited by spark1 (edited 05-14-2006).]

I thought our fiero's were OBDI

regardless as for testng they are completely clean, not even worth running the test as virtually nothing shows up. This was the original reason when I did mine there was such a high incentive to do it as the polution was virtually non existant on CNG.

I have an Explorer that is CNG/Gasoline, you can switch back and forth. I've often thought about what it would be like in the fiero, but for real, the tanks are big. CNG is around $1.20/gallon compared to up to and over $3.00/gallon gasoline.

I plan on doing an electric conversion in a few years. I bought a Formula for the better suspension and brakes. Electrics can get heavy. I am hoping for battery technology to get better...

Any reason you picked NG over electric?

quote Originally posted by mjuch: I plan on doing an electric conversion in a few years. I bought a Formula for the better suspension and brakes. Electrics can get heavy. I am hoping for battery technology to get better... Any reason you picked NG over electric?

Are you asking me? If so, It's cause I bought the whole daily driving truck for $900!!!