Running Propane

[Gambler]

When it comes to injecting propane or cng, should one run more fuel than normal, so you're not running lean? If anyone has experience w/ theses setups, please enlighten me.

Thanks

[dvst8r]

People still do this? I though this died out in about '02.

[JP-4.5]

Sounds very dangerous! Would not want a leak to happen anywhere in a system using flammable gas..

Is there that much to gain from using propane/CNG compared to using water or methanol?

[DirtyMaxx03]

Originally Posted by JP-4.5

Sounds very dangerous! Would not want a leak to happen anywhere in a system using flammable gas..

Is there that much to gain from using propane/CNG compared to using water or methanol?

No, there's a good reason people quit using it.

If you want power, use nitrous.

[Rockwerx]

I ran propane on an older mechanical injected truck and it really helped to clean up the exhaust emissions as well as gaining some overall economy. Todays generation of CR engines run so much more efficient that it is not as effective for milage gains or creating more power.

[Gambler]

Originally Posted by Rockwerx

I ran propane on an older mechanical injected truck and it really helped to clean up the exhaust emissions as well as gaining some overall economy. Todays generation of CR engines run so much more efficient that it is not as effective for milage gains or creating more power.

What was your application? I would like to try to use it to get a better fuel mileage. I already have the set up, just haven't hooked it up yet. Other than buying some propane/cng, I don't really have much money involved. It will be going on a 97 12v, my signature truck. Not trying to use it as a power adder. It is my understanding that the #2 fuel mixture should be a little rich vs. lean because the propane/cng will help burn excessive fuel.

[JWhite]

Originally Posted by Gambler

What was your application? I would like to try to use it to get a better fuel mileage. I already have the set up, just haven't hooked it up yet. Other than buying some propane/cng, I don't really have much money involved. It will be going on a 97 12v, my signature truck. Not trying to use it as a power adder. It is my understanding that the #2 fuel mixture should be a little rich vs. lean because the propane/cng will help burn excessive fuel.

LP and CNG are fuel, if anything it will smoke MORE. If you want a quality CNG kit look up Marc Deluca. But be warned, CNG kits are pricey compared to what you can get a LP setup for (mostly the cost of the tank is higher).

Neither fuel is any more dangerous than diesel fuel, just don't be stupid. Depending on how close a CNG station is to you, LP is a better bet, BUT you won't be able to get LP filled on a truck for as cheap as your house.

Both of these fuels are good candidates for extra MPG and HP, just don't bolt on a kit and expect 150hp, typically 75 on a CNG equipped truck. The main limiting factor will be the line size/regulator flow capabilities. If it were my truck, CNG would be on it for extra mpg, already makes plenty on #2

[cummins03]

Smoke more? Since when do either of those fuels create smoke when burned?

[Leiffi]

Originally Posted by cummins03

Smoke more? Since when do either of those fuels create smoke when burned?

Since The Big Bang. They use oxygen, less left for diesel to burn clean.

[Gambler]

Why do others claim that it cleans up better w LP/CNG?

[90dodge]

My guess is because they don't know what their talking about. Simple chemistry tells you unburnt fuel makes smoke.

The one thing i definetly don't agree with is that they are any less dangerous than diesel. Strike a match next to some open diesel, then do the same next to a propane tank with an open valve and tell me how it goes.

Sure, you might get better diesel fuel mileage running pro/cng, but go ahead and try it and let us know how much more your spending on the alternative fuel you are paying for. We can always use some more carnage pictures if you decide to get wild with it too. Lol

[Snedge]

My propane grill will not smoke until I throw the steaks on.

[JWhite]

I will come up front and say I was probably wrong about LP being "safer" but CNG is for sure. You can open a CNG tank valve next to a torch and it won't light. CNG has a very narrow window of AFR that it will burn.

Back to the smoke.... A CNG kit is going to inject into the compressor inlet, so let's say 1/8 (I really don't know, just putting a number up) of the air your turbo compresses is CNG, less air for diesel to burn. A friend of mine put a cng kit on a LBZ Chevy and I had to take almost 30% of the pw out to clear up smoke 100% (started with a stock tune). He is getting 38-42mpg hwy on diesel, not sure on cng but at $1.69 there is a benefit.

[90dodge]

You are probably right about that, the only cng i have been around was in a sealed system. I was referring to past experiences of leaving the valve on a cooker open too long. Lol

[90dodge]

How much cng were you having to use to attain 38mpg?

[JWhite]

I'm not positive on his regulator settings, but his 15 gal cng tank @ 3600psi will last him just a tad longer than a 26 gal tank of diesel IIRC. I'll try and ask him so I'm not posting a lot of misinformation.

[Smokie Okie]

Originally Posted by Gambler

When it comes to injecting propane or cng, should one run more fuel than normal, so you're not running lean? If anyone has experience w/ theses setups, please enlighten me.

Thanks

You will still be controlling your AFR with your foot/AFC on a 12 valve. Don't install the kit for power gain. By the time you're making enough extra power from LP you'll be detonating and blow your head gasket.

As far as installing it for fuel economy, you're simply trading one fuel for another and will still require the same amount of BTU's to get you where you want to go at whatever speed makes you happy. The BTU's from LP or CNG will cost less, but you have to figure out how long it will take to offset the cost of the kit and the headache of keeping two fuel tanks filled.

Originally Posted by DirtyMaxx03

No, there's a good reason people quit using it.

If you want power, use nitrous.

This^^^^

Originally Posted by JWhite

LP and CNG are fuel, if anything it will smoke MORE. If you want a quality CNG kit look up Marc Deluca. But be warned, CNG kits are pricey compared to what you can get a LP setup for (mostly the cost of the tank is higher).

Neither fuel is any more dangerous than diesel fuel, just don't be stupid. Depending on how close a CNG station is to you, LP is a better bet, BUT you won't be able to get LP filled on a truck for as cheap as your house.

Both of these fuels are good candidates for extra MPG and HP, just don't bolt on a kit and expect 150hp, typically 75 on a CNG equipped truck. The main limiting factor will be the line size/regulator flow capabilities. If it were my truck, CNG would be on it for extra mpg, already makes plenty on #2

I ran LP for a couple of years. It didn't smoke more. Again, you're controlling the AFR with your foot/AFC on a twelve valve.

If you get an LP tank at your house you can install a wet line on it and fill your vehicle at home for the same price.

Originally Posted by JWhite

I will come up front and say I was probably wrong about LP being "safer" but CNG is for sure. You can open a CNG tank valve next to a torch and it won't light. CNG has a very narrow window of AFR that it will burn.

Back to the smoke.... A CNG kit is going to inject into the compressor inlet, so let's say 1/8 (I really don't know, just putting a number up) of the air your turbo compresses is CNG, less air for diesel to burn. A friend of mine put a cng kit on a LBZ Chevy and I had to take almost 30% of the pw out to clear up smoke 100% (started with a stock tune). He is getting 38-42mpg hwy on diesel, not sure on cng but at $1.69 there is a benefit.

I'm not sure I follow you on your first statement. If you open a CNG valve to air and provide fire, it will burn. The tank will not explode because the fire can't follow the fuel thru the valve where there is no air, but the fuel outside the tank will burn provided that there is enough fuel.

[JWhite]

Originally Posted by Smokie Okie

You will still be controlling your AFR with your foot/AFC on a 12 valve. Don't install the kit for power gain. By the time you're making enough extra power from LP you'll be detonating and blow your head gasket.

As far as installing it for fuel economy, you're simply trading one fuel for another and will still require the same amount of BTU's to get you where you want to go at whatever speed makes you happy. The BTU's from LP or CNG will cost less, but you have to figure out how long it will take to offset the cost of the kit and the headache of keeping two fuel tanks filled.



This^^^^



I ran LP for a couple of years. It didn't smoke more. Again, you're controlling the AFR with your foot/AFC on a twelve valve.

If you get an LP tank at your house you can install a wet line on it and fill your vehicle at home for the same price.



I'm not sure I follow you on your first statement. If you open a CNG valve to air and provide fire, it will burn. The tank will not explode because the fire can't follow the fuel thru the valve where there is no air, but the fuel outside the tank will burn provided that there is enough fuel.

I'm sure if you opened a tank on a house fire it might light up, but it will just blow out a campfire. Have you tried it? Didn't think so. And how many people have wet lines on a house tank? Probably 1 guy that works for a gas company.

And the AFC thing doesn't make sense, its a boost reference. And if injecting an alternative fuel in the turbo inlet, some of that "boost" isn't really air.

[Joesixpack]

Originally Posted by Gambler

Why do others claim that it cleans up better w LP/CNG?

Duel fuel systems perform best under moderate to high load and can often equal or better diesel alone.

However under light load emissions of both carbon monoxide and hydrocarbon increase as diesels are unthrottled. The mixture becomes to lean and combustion degrades leaving partial reacted hydrocarbons in the exhaust.

The high emissions and poor efficiency under these conditions leads to the need to smart controls to optimize the conditions of dual fuel operation.

As a "performance" angle. Forget it. From a cost per mile angle its entirely possible to be cheaper depending on your cost for the dual fuel and how smart your controls are.

[Smokie Okie]

Originally Posted by JWhite

I'm sure if you opened a tank on a house fire it might light up, but it will just blow out a campfire. Have you tried it? Didn't think so. And how many people have wet lines on a house tank? Probably 1 guy that works for a gas company.

I work around CNG every day. Thanks for the reply though.