CNG instead of gas

[shade]

Out of curiosity how would our trucks fare if someone converted it to use CNG instead of gasoline?

Horsepower go down?

 

[AWDisuzu]

i dont even know what cng is. :-(

 

[westmintrans]

hp would go up.... and you wouldn't need any water/meth injections. although you wouldn't get the full effect without changing the compression ratio. The main diffrence is CNG has an octane rating of 104, i guess if you have forced induction you could turn up the boost higher.

 

[v8eater]

i dont even know what cng is. :-(

Compressed Natural Gas.

It's the stuff piped in to houses for non-electric heat. You would be your own gas station...

 

[GotRidOfTheHemiForThis]

you can do that? Why does this sound like an idea i get at 2 am when im drinking lots?

 

[wyoramsrt-10]

you can do that? Why does this sound like an idea i get at 2 am when im drinking lots?

Hey hold my beer and watch this

 

[GotRidOfTheHemiForThis]

Hey hold my beer and watch this

yea i can see my house blowing up as im filling my new gas with a cig in my mouth and a beer in my other hand whoops my bad lol

 

[v8eater]

http://www.myphill.com/

http://www.cnn.com/2007/TECH/03/09/cars.naturalgas.popsci/index.html

http://www.whatgreencar.com/cng.php

http://www.greencarcongress.com/2004/09/natural_gas_fue.html

 

[SilvrSRT10]

Very interesting. I had some "what if" thoughts on using CNG in place of nitrous and how effective would it be. Pros - cheaper, readily available. Don't know if it would have any HP increase like N2O though. I know the diesel guys use CNG in their trucks but they run a higher CR. Haven't looked into it any further. What are your thoughts/knowledge?

 

[Floor]

LPG

Hi Guys, in Europe this fuel is called LPG (liquified Petroleum Gas) or autogas. It consist of propane and butane, two subproducts from oil refineries. It is quit easy to make it suitable as a fuel for combustion motors hence the lower cost at the station (about 50% compared to regular gas in belgium).
Besides the cost there are a couple benefits: better for the engine because it is injected in a gas stage, not liquid, lower emmisions (so the green f**kers are happy in that case ).
You would need to have a receiver tank installed in your bed but this gives you more traction on the wheels won't it :rock:
BHP is about the same (different stories going arround) but the mileage will be 20% higher due to a lower specific energy.
When you do quite a few miles/year it pays itself after a couple years.
It is used on almost EVERY US car, truck or VAN you see arround here because the difference in fuel cost are that big. Availability at the gas station is ok aswell, :dontknow: how the situation is over there...
Have a look at www.delpgdokter.be for more details. these guys did a SRT before (with PICS)

 

[AWDisuzu]

i can get propane here at my gas station, but not sure about CNG.

 

[Muzzy]

CNG would not work very well for a few reasons: You would need to increase your compression ratio significantly (13:1 or 14:1) to take advantage of it. You could not fill your tank from your house since your home natural gas connection is low pressure (unless you compress it). With low pressure you would never get the volume or fuel to even get you down the driveway. Natural gas has less BTU's per gallon than gasoline (91,000 BTU's for CNG vs. 136,000-152,000 for gas). Again, you would lose horsepower unless you increased your compression ratio to take advantage of the higher octane rating. With less BTU's per pound or gallon your mileage would take a hit. Any cost savings (if it is even cheaper) would be offset with more frequent fill-ups.

It is better to run CNG in an engine designed to run CNG, not the Viper engine. Not to mention the expense in converting it to do so.

-Muzzy

 

[Floor]

i can get propane here at my gas station, but not sure about CNG.

not the same thing. If I'm not mistaking Propane bottles are 200 bar. CNG tanks in a car/truck arround 8 bar (120 psi)

 

[Floor]

CNG would not work very well for a few reasons: You would need to increase your compression ratio significantly (13:1 or 14:1) to take advantage of it. You could not fill your tank from your house since your home natural gas connection is low pressure (unless you compress it). With low pressure you would never get the volume or fuel to even get you down the driveway. Natural gas has less BTU's per gallon than gasoline (91,000 BTU's for CNG vs. 136,000-152,000 for gas). Again, you would lose horsepower unless you increased your compression ratio to take advantage of the higher octane rating. With less BTU's per pound or gallon your mileage would take a hit. Any cost savings (if it is even cheaper) would be offset with more frequent fill-ups.

It is better to run CNG in an engine designed to run CNG, not the Viper engine. Not to mention the expense in converting it to do so.

-Muzzy

Muzzy, if you're talking (top) performance wise, you're right. CNG is slightly less HP performand. Mileage goes up about 20% like I said. But this works fine when you do a lot of miles at cruising speeds. You can switch at any time to regular petrol in case you really need those ponies to come alive to the full extend. biggest tanks are 230 L (60 gallon). conversion cost is arround 4000 euro (5000 USD). I don't think US market (CNG dealers, suppliers) is organized yet for a big boom in sales but the opposite is true in europe. regards.

 

[shade]

It wasnt a project or anything more of a what if...

I mean I see the tahoe's and police cruisers that converted to CNG and thought how would t fare on the truck.

Out of curiosity how do you increase compression?

 

[Muzzy]

It wasnt a project or anything more of a what if...

I mean I see the tahoe's and police cruisers that converted to CNG and thought how would t fare on the truck.

Out of curiosity how do you increase compression?

Typically you would offset grind your crankshaft on the rod journals to increase the throw. Then you would need a longer rod resized to the new journal diameter. I have also seen shops weld onto the journal (and regrind it) to maintain the stock diameter. Compression ratio is the volume of the cylinder to the volume of the "squish" area when the piston is at top dead center.

-Muzzy

 

[Muzzy]

I also forgot you can increase the dome on your pistons thus reducing the squish area. That would also increase compression ratio without messing with the crank and rods. There are limitations (piston to valve clearance, etc) on how much compression you can get with just pistons alone.

-Muzzy

 

[AWDisuzu]

it's really easy to make high compression pistons. even if you're the first one, just make a mold. (with the engine out)

basically, you pull a spark plug, put some liquid or paste molding putty into the cylinder, then rotate the crank so that the piston comes to TDC, squishing out the excess putty.

then pull the piston out and there you go. send it into JE or your manufacturer of choice along with the bore and stroke and they can machine a high compression piston for ya

~mike~

 

[Muzzy]

Crap, that is a lot easier than it used to be. I remember spending some time with the calculator and cutting valve reliefs into pistons.

-Muzzy

 

[K-80-123]

I have had many company cars with CNG....they run just fine the problem has always been range....in a car they put the tanks in the trunk and were only good for about 100-120 miles before you needed to fill up.

I also had a 3/4 ton 4x4 Ford truck that was converted to CNG and we put 3 large tanks in the bed....I could go 300 miles on CNG and another 300 on gas so it had a good range.

They make home compressors to fill you car at home using your natural gas service line....but they are Very Expensive.

All in All I could not tell any diff between CNG and gas when driving....although it did seem like Gas had more punch to it when you needed it.....hope this helps.