Propane injection

[mmmmmm]

I did received few quotes to install propane injection system. Price range from 3000$ to 6000$. They promise a lot of good staff (fuel mileage, power, extends engine life etc.). Is this a good investment or just another B.S.? Thank you.

[Hammerhead]

Is this a conversion from diesel to propane? You do know there is less energy in an equivelant volume of propane, so you would need large tanks (pressure vessel cilynders) and would probably have refueling issues, unless you have a dedicated route and this has already been factored.
As a power adder or attempt to increase fuel economy, I wouldn't touch it.
I do know there are Natural Gas & Propane fuel versions of the ISX, as well as Cat & Detroit, but there are hardware changes required. I used to haul countless CNG Cat 3406 engines, I know for sure they use different pistons and turbos than diesel and were not cross compatible.

[Rawze]

Unless you can get the propane for about 20% cheaper than of the cost of diesel per gallon, it is not worth the conversion in fuel consumption alone,.. and at that rate, it still will not pay not pay for having it done. You will be good to break even because propane has less energy per gallon. -- it is one of those things that if you aren't set up for it from the beginning and getting the fuel at wholesale costs (because you perhaps haul propane for a living?), or aren't being subsidized by the govt to run it, .. it is not worth it.


The second issue is that as soon as you pour a fuel of any type into the intake of a modern diesel, you loose all control of internal friction. -- bad things like liner fretting, fuel impongementm, and all other issues set in real fast. - This severely shortens engine life of these modern beasts.. they are noting like engine of yester-year.

Simply using some decent custom engine tuning and keeping the engine in tip top shape would far exceed any type of mods like this. Sounds like a bunch of smoke up someones arsse just like you hear on the XM rario and a bunch of false promises to me.

[in2trux]

Propane injection worked good on old mechanical engines for making more power without getting crazy with timing and over fueling. They had massive pistons and.blocks that could handle near molten temperatures day in,day out. They DIDN'T have precision computer control of combustion like modern engines that can make far more power without it.

People think I'm full of s__t when I tell them about a 3406 I had that would push a nice flame tip out of the short meat hauler turnout stacks, very visable on a dark night out west.
I guess you had to be there., it was raw and very cool. Fuel was also under a buck and average mpg was under 5.

[jti2015]

If you're looking to convert from diesel to LPG then you'll need a new engine, LPG uses a spark ignition like gas to burn the fuel. Plus the compression ratio is much lower than diesel. I had several gasoline engines that I used a propane conversion kit. Fuel was cheaper plus the oil stayed clean forever.
My guess is that you're talking about a propane kit to use on a diesel engine. They will add some HP and MPG by assisting the diesel engine to burn the diesel fuel more completely. The cost/mile for fuel is not going to decrease when you amortize the cost of the additional equipment plus the added expense of LPG. If you're looking for HP it will add some but at a cost.
I wish someone would do some emissions testing to see if LPG would allow diesel engines to meet EPA regs without all the BS from current EGR/DPF/SCR systems.

[Unilevers]

(10-12-2016 )jti2015 Wrote:  If you're looking to convert from diesel to LPG then you'll need a new engine, LPG uses a spark ignition like gas to burn the fuel. Plus the compression ratio is much lower than diesel. I had several gasoline engines that I used a propane conversion kit. Fuel was cheaper plus the oil stayed clean forever.
My guess is that you're talking about a propane kit to use on a diesel engine. They will add some HP and MPG by assisting the diesel engine to burn the diesel fuel more completely. The cost/mile for fuel is not going to decrease when you amortize the cost of the additional equipment plus the added expense of LPG. If you're looking for HP it will add some but at a cost.
I wish someone would do some emissions testing to see if LPG would allow diesel engines to meet EPA regs without all the BS from current EGR/DPF/SCR systems.

straight lpg engines meet Particulate matter, but not NOX emissions. So all LPG engines have to run EGR and SCR.

[preacherboy24]

(10-12-2016 )in2trux Wrote:  Propane injection worked good on old mechanical engines for making more power without getting crazy with timing and over fueling. They had massive pistons and.blocks that could handle near molten temperatures day in,day out. They DIDN'T have precision computer control of combustion like modern engines that can make far more power without it.

People think I'm full of s__t when I tell them about a 3406 I had that would push a nice flame tip out of the short meat hauler turnout stacks, very visable on a dark night out west.
I guess you had to be there., it was raw and very cool. Fuel was also under a buck and average mpg was under 5.

My Dad had a cabover Mack with a V8 Maxidine......it would throw an 8" flame out the stack. Saw it myself.

[preacherboy24]

The kits out there are supplemental kits. They do help older engines by increasing the combustion efficiency. It helps create a better flame front when the fuel is squirted in the engine because the propane ignites before the diesel. Instead of 85% of the btu's being burned are driving the piston down you get closer to 95%. In actuality the propane isnt even a part of driving the piston down. Diesel truck magazine took a 5.9 that was at 15mpg and got it to 24 but you have to remember that you are consuming propane.....which is more expensive than diesel right now.

A place called Carburetion and Turbo systems in Minnesota can give you more info. They specialize in these systems and I know the owner.

Would I do it? No. My guy listed above can get you a system for $1400 and you buy the tank and install it yourself. He says its getting the guys a 1mpg difference in fuel mileage.....but by the time you figure in the propane burned its not much of an advantage.

I will say that propane burns cleaner so by definition you would be burning cleaner.....maybe if you idled a lot you could substitute propane by as high as 50% and help there. I would not spend $3k on a system.....just wasted money compared to the mandate removal. Move on.

[Kevin7898]

Propane to a diesel is like nitrous to a gas engine. Except better. As stated it hepls burn the fuel more completely, but it also significantly lowers your egt. So thus allowing you to dump more fuel and air in and get a safe burn. Works even better with ecm controlled motors when they are tuned and have the internals to match.