Liquid Propane

[mobilevet]

Anyone using propane in their truck?

I've read that it can increase fuel mileage and the percent of combustion of the fuel resulting in a cleaner burn.

Just wondering if anyone has any experience with this and how/if the PMD responds and/or if the computer has to be manual adjusted etc.

[Mark Rinker]

I ran propane on a 2001 Duramax. Had good results for adding power and increasing towing range capabilities. Never found any setting where a significant decrease in combined fuel consumption was consistantly observed. Evenually blew a head gasket - although 2001s are known for doing this, even in stock form so I'll never know for sure if the propane was to blame. It couldn't have helped... ;)

Also, your 6.5 may have an inherent weakness in the bottom end (block castings) and the only propane systems available I know of for the 6.5 are mechanical (not digital) and are easier to adjust past the 'point of no return', which might not be all that far if you already have a bad block. Cylinder pressures can go through the roof quickly if you combine too much fuel, propane, and enough boost (oxygen) to burn it all.

Something has to give - none of it easily replaced. (Piston crowns, connecting rods, crankshafts, head gaskets) There is also limit as to what you can expect from the 4L80E transmission as well.

LP has ~65% of the energy content (BTUs) per gallon as #2 diesel, but follows the price of #2 at about 70%. This means that gallon for gallon, LP is even MORE expensive than diesel!!!

There is a sweet spot at about 4:1 diesel to propane. Different settings are needed for unload and loaded use of propane/diesel mix to optimize fuel consumption. The correct boost setting on top of all that is yet another variable. So far, nobody makes a computer to monitor exhaust temps and 02 content, mixing the fuels dynamically while controlling boost - and it would only make sense to market such and animal if you got the second fuel really cheap...hydrogen might be another story someday.

My advice would be: Pass - unless you can source LP for less than 60% of the price of #2 diesel, and plan to use with gauges and cautious moderation.

[wade-ve7trw]

http://franzh.home.texas.net/dualfuel.html. Here Is a write up on the idea of using propane and diesel together.

[mobilevet]

..hydrogen might be another story.

Actually this was where I was heading. My particular application is not for more power but for better fuel economy. My thought was that a small amount of gas would increase the fuel economy enough to make it worth my while. I read that 30-50% increase economy might be achieved. Since I'm not looking for more power I could be very conservative with the gas and maybe not stress the engine too far.

I asked about LP because I know that it is more conventional and thought more folks would have experience with it, but my real idea was the use of a hydrolysis to produce hydrogen on demand. It would not only be cheaper than LP, but since it would be produced in a low pressure environment right off the bat there'd be less parts to deal with, etc. and since it would not have to be stored then there would be low/no risk of explosion in the event of a wreck or such...

Back to the original line of questioning, I still wonder about how the computer would react to the gas?? Any thoughts??

[Robyn]

You might want to think about a water alcohol injection system for your 6.5
This will cool off the EGT and the alcohol will add some power too.

A denser mix is always better and will be far gentler on the little diesel creature under the hood..

These systems can be set up with a pressure switch that turns the system on at a preset boost, Oh say 8 PSI it comes on and will stay on until you get your foot out of the fan. :D. Above 8-10 PSI you are building some serious heat anyway.

Just a thought.

Robyn

[wade-ve7trw]

http://www.bankspower.com/tech_propane.cfm here is a page from banks turbo systems on prpane.

[Mark Rinker]

I read that 30-50% increase economy might be achieved.

I experimented with a range of settings under very controlled circumstances, over many many miles and came to the conclusion that all claims of extraordinary economies mixing LP and diesel are simply not true.

If you tow heavy, there is economy if you get the mix and boost set just right for the conditions. Daily driving, unloaded you might actually burn MORE fuel, not less.

The jury is still out for onboard hydrogen generation. If you have a big alternator that is capable of generating plenty of amps, you might be able to generate and induce hydrogen, but the resulting parasitic drag will probably eat up any additional fuel produced.

Now you could generate hydrogen at home, from a solar array or wind tower, but watch this video and consider the SIZE of tank you'd need for the hydrogen...

http://www.youtube.com/watch?v=xEdQRVQtffw&feature=related

[mobilevet]

Hmmm... all very interesting. Thanks for all the comments - much to think about before going to the trouble, expense, and resulting variables. Thanks!

[Mark Rinker]

Here is a thought for you - although it doesn't easily apply to pickups...

What about all the rear axles spinning tires on FWD cars and vans nationwide? What if those rear wheels were spinning wheel mounted generators? Similar to hybrid cars, except no power produced from rear axle, just generating electricity to produce the hydrogen that is routed up front to help power the front wheels.

Might just be another stab at the perpetual motion machine, but I think the parasitic drag would be less than a high amp alternator on a small pulley. Consider the size of the tires and the fact they are back there spinning around anyway...

Its all about finding more efficiency out of the 60% wasted on most passenger cars...

[mobilevet]

Thats a good thought.... I think the hydrolysis units require like 2 amps/40 volts

[DmaxMaverick]

It really doesn't matter where you get the power. Parasitic loss is parasitic loss. If you need to generate 2 amps at 40V, the HP/KW requirement is the same regardless of how it is generated, minus the parasitic loss. A generator is already being driven by the engine. Increasing the power output of that generator will not increase the parasitic loss. Adding the weight and coupling friction to the rear wheel(s) will increase the parasitic loss. There'll be no "perpetual motion" to be be had here. And, the engine driven generator is already designed into the system, not requiring additional engineering or hardware to generate the needed electricity.

[Mark Rinker]

I see what you are saying, but nobody is seeking perpetual motion. We're seeking to capture lost energy and use it. Cars and trucks aren't operating at 100% efficiency. (i.e. Inefficient incandescant light bulbs inside homes are burned for light, but also generate heat as a byproduct. In the summer, thats bad. In the winter, its a tiny benefit.)

What I don't understand is this:

If you have a 100A alternator, and only 40A are used under normal operating circumstances, is the unused 60A still 'available' with no additional parasitic loss, or does parasitic loss increase directly with each additional amp needed?

I understand there is no perpetual motion machine, but there IS wasted energy in machines that can be captured and harnessed. The turbocharger is a great example of this. Waste heat energy becomes mechanical force becomes pressurized air charge becomes a more efficient air pump as fuel is more completely burned.

Nobody argues the notion that a turbocharger gives back more than it takes - because we all accept that they work.

So you still a pinwheel out the window of a moving car, and that pinwheel generates current to light a bulb, or break water into hydrogen and oxygen. Parasitic loss again?

Why doesn't the turbocharger cause more parasitic loss in the form of backpressure than it produces in the form of boost?

Not arguing or defending snake oil hydgrogen boosters on the internet here - just trying to understand where we can capture that 60% inefficiency and convert it to something useful...

[DmaxMaverick]

Still, it's all a loss. The alternator has a static parasitic loss. The belt to pulley, bearing, and inertial friction. Additional load will depend on the current demand. There is no "loss of 60 amps if it's only putting out 40 amps". The loss is translated from fuel energy transfered through the belt to the alternator. The pinwheel example is the same. Wind resistance spinning the pinwheel is generated when the fuel energy is converted to forward motion, making the wind to spin it. And, you will still have additional parasitic loss, as it is not only the pinwheel in the wind, and it, in itself, is not operating at 100% efficiency.

[JTodd]

Studies show that hydrogen producing hydrolysis runs at about 70% efficiency. So for the 2 amps at 40 volts = 80w = .11 hp you are using to crack water, you are creating .077 hp.

Where the benefit of hydrogen comes in is either in more efficient cracking (bacterial processors) or shifting the burden to renewable sources such as solar, hydroelectric or nuke.

For Gasoline the refining process consumes the conversion, but refining uses comparatively less energy than cracking water molecules. Hydrogen might have more energy per unit, but it is harder to get at.

[GMC Hauler]

If you have a 100A alternator, and only 40A are used under normal operating circumstances, is the unused 60A still 'available' with no additional parasitic loss, or does parasitic loss increase directly with each additional amp needed?



Yes, there is additional loss for each amp you draw.

1. I Squared R losses (internal resistance of the wiring)
2. Eddy current losses.

[mobilevet]

What about a solar panel mounted on the roof of the truck to power the hydrolysis?? Then it's a symbiotic relationship - not parasitic

[GMC Hauler]

What about a solar panel mounted on the roof of the truck to power the hydrolysis?? Then it's a symbiotic relationship - not parasitic

It would be easier to use the solar panel to charge the batteries and/or power the electrical loads directly. There is a continuous electrical power used be the vehicle.

[Mark Rinker]

Good answers, interesting stuff.

So - back to the thing we all know that works...the turbocharger.

How does it capture/use otherwise wasted heat energy - AND create a net gain over a NA version of the same engine?

Extra credit - the belt driven supercharger.

[GMC Hauler]

How does it capture/use otherwise wasted heat energy - AND create a net gain over a NA version of the same engine?.

It's all about PV/T, or Bole's Gas Law.


http://en.wikipedia.org/wiki/Boyle's_law

Hot gas has energy. It is wasted if it just goes out of the exhaust.

By allowing the hot presssurized gas (in the exhaust manifold) to expand into a larger space (downpipe), it gives up some of it's pressure and temperature energy by pushing it's way to the lower pressure area, via the turbine blading that is in it's way.

Piston does the same thing. Same principle in the cylinder.


Extra credit - the belt driven supercharger.


Not the same. It uses energy from the engine to drive itself. It's like an alternator. An alternator needs a small amount of energy that it created to go back and power itself (the field winding) to continue to create the output you use. When you draw 40 amps from the alternator, it really creates 45. 40 for you and 5 to make more. (the numbers are an exaggeration, I don't know how much it needs). Little bit of a feedback loop there.

[Mark Rinker]

So - how about we use an exhaust driven turbine to spin an alternator, instead - capturing otherwise wasted energy in the form of heat? Or introduce that heat into some chemical reaction that gives off H2? Or both...?

[DmaxMaverick]

So - how about we use an exhaust driven turbine to spin an alternator, instead - capturing otherwise wasted energy in the form of heat? Or introduce that heat into some chemical reaction that gives off H2? Or both...?

The turbo needed to make engine power is already exhausting the available heat/gas energy, and more. This is where the turbo efficiency plays a part. Most 6.5 turbos are operating beyond their peak efficiency at higher power levels. When the point of diminishing returns is reached, there is no more energy to be had, and taking more returns less and less.

You could place a pinwheel/generator after the exit of the tailpipe. This would not cause a restriction, and you would be able to capture the remaining energy the turbo couldn't use. [sarcasm]

There's only so much energy to be scavenged. Once you pass the point of an equal return, you get back less than you invest. This defeats the purpose.

[Mark Rinker]

Once you pass the point of an equal return, you get back less than you invest. This defeats the purpose.

Sounds like the closing statement from the "MRE - 2008 Annual Financial Report" :D

[JohnC]

The Wright R3350 engines used to power the Lockheed Constellation had three power recovery turbines in the exhaust connected back to the crankshaft, in additional to a supercharger. They ran about 15 lbs of boost to put out 3400 hp on 115/140 octane fuel. The power reccovery turbines accounted for about 500 of those horses.

[Mark Rinker]

I am bumping this interesting thread from 2008 back to the top, incorporating some new developments in available technology.

My first experience introducing a second fuel into the intake of a Duramax was the MSD digital propane injection system. I found that experience to be eye opening, yet never found a measureable or repeatable benefit to burning propane, mostly due to availability and cost per BTU of propane vs. #2 diesel.

Recently, Jim posted a new article about onboard hydrogen generation. About this same time, I have purchased a 2009 K3500HD with dual 120AMP alternators...

What say ye? Will it add fuel efficiency over burning #2 alone, or will the cost of aquiring and installing the system, sourcing sodium hydroxide, etc. outweigh any increase in addition mileage?

THE QUESTION - will the increased parasitic drag of the alternators on my engine (while the system is "ON" and generating hydrogen) consume more BTUs of #2 diesel in relation to the BTUs of hydrogen released from the generators?...or...will the system yield a net gain in efficiency from my engine, returning a measureable ROI over time?


http://www.mpeperformance.com/

[GMC Hauler]

It breaks the laws of thermodynamics: You will loose efficiency if you take rotational energy, convert it into electrical energy, to chemical energy, and then back to rotational energy through combustion.

If you "regenerated" by making the electrical power from braking, coasting, etc. and used that electrical power to generate and store hydrogen, then yes.

On submarines, we break water down with electrolysis to make oxygen to breathe. The process uses A LOT of electricity. I have read several claims to companies selling these items that they use special chemicals; so do we. Still takes a lot of power.

It is too good to be true.

[More Power]

Without knowing more about the HHO generators, I'm guessing a garage unit that converts water/electrolyte to compressed hydrogen gas would be the best and most efficient way to get a decent ROI (return on investment) if you re-roofed your garage using solar panels. The economics might work too with grid power, but then you'd have a coal/nuclear/hydro powered vehicle, depending on where you live. ;)

[Mark Rinker]

Jim - from earlier in this same thread...please view the link below to see storage requirements this guy needed for his 'off-grid' hydrogen needs, including a hydrogen powered car... :eek:

I am betting he is a really smart engineer with a healthy corporate salary, judging from from 1) the no-expense-barred equipment, and 2) choice of footwear in the video. ;)

Subsidies need not come from the government - they can also come from your own good fortune - ROI be damned...







...

The jury is still out for onboard hydrogen generation. If you have a big alternator that is capable of generating plenty of amps, you might be able to generate and induce hydrogen, but the resulting parasitic drag will probably eat up any additional fuel produced.

Now you could generate hydrogen at home, from a solar array or wind tower, but watch this video and consider the SIZE of tank you'd need for the hydrogen...

http://www.youtube.com/watch?v=xEdQRVQtffw&feature=related

[JohnC]

If you are burning fuel to generate electricity to break water down to produce hydrogen to burn (back to water) then you can't win. The reason is your start (water) and end (also water ) are the same. If, OTOH, you can break something down to produce hydrogen that takes less energy (to break down) than is produced when you then oxidize the hydrogen to water, you could come out ahead. If the cost of that something was low enough... Otherwise, the only way to make it work is if your electricity is "free" (solar, wind, etc).

[Mark Rinker]

Then how are a belt driven superchargers explained? Superchargers introduce parasitic drag, but their benefit is clear - the power they use is less than the power that is created as they help the air pump (engine) they are bolted to closer approach its ideal volumetric efficiency.

In this case, the belt driven parasitic drag device is an electric power generator (alternator), that runs undertaxed and far below its peak efficiency most of the time. At some ideal input RPM and current load, the alternator runs at its peak efficiency, for the amount of engine horsepower (can also be measure in watts) required to spin it.

Theory: If the power (wattage) needs of a given HHO generator can effectively be matched (sized) to utilize the available watt potential of the OEM Delco alternator - without pushing it past peak efficiency and further taxing the diesel engine - those (exess) watts available could be convertered to another motor fuel (HHO), introduced and burned for a net (wattage/BTU/horsepower) benefit from the existing (terribly inefficient) integrated Duramax air pump/electrical generator system that we use to propel ourselves down the road, light headlights, heat power seats, recharge starting batteries etc. mostly for transportation to and from 'work'...which really isn't 'work' by these definitions at all...LOL ;)

I think the best way to describe any benefit would be to lessen the inefficiency of the current system, by using excess capacity, and converting that capacity into a useable input fuel - in this case, HHO.

The key would be to identify the excess capacity available in the OEM GM 120amp alternator, and match that to the appropriate sized HHO generator, and then only ask for those watts in an effective manner - i.e only run the HHO generator when the diesel engine is operating at or near its optimal efficiencies (~1600-1800rpm), and not at idle or during start and stop driving.

Extra credit: What if the engine was already equipped with dual 120amp alternators. More excess capacity, or just more parasitic drag?

Myth Busters: Plausible - but mostly dumb luck if you bolt an HHO generator to an engine and experience a measureable gain, without careful consideration of the engines alternator, batteries, and their capacities - as well as the efficiency of the engine.

[Robyn]

Ok, I can't resist jumping in here.

My personal feeling on this (as usual, somewhat sceptical)

The best way to save on fuel is to keep the powerplant as simple as possible.

The more extra goodies that get bolted on, the more stuff to fail and or give issues out on the road.

If its power you want, ya gotta feed the pony or the pony does not work.

There is no free ride here. All this converting and reconverting is just a way to "Convert your $$$$$ into someone elses"

Propane injection is fine if used as a power enhancer/charge cooler.

The only gain really is the added power, not economy.

My bet is that after you factor in all the Initial cost, the parasitic drag of the extra alternator and the hastle, that the savings if any will be actually a minus number.


Hydrogen being converted from water takes energy. Pay me now or pay me later.

Now as was mentioned, if you could use solar/wind power to run the Hydrogen generators and then can the stuff, it might be a good thing.

At what cost ????? the equipment is not cheap and then the cost of the chemicals on a continuing basis $$$$$$$$???

If this is all in the name of "CLEAN HORSEPOWER" Then its probably a great idea but, as a $$$$$ saving plan, Nooooooooo I dont see it.

Back in the days of the "Fuel shortages" (Yeah right, just more lies) Gm came out with the 6.2, as history will bear out, these were not a power house, not even but, the little critters got great mileage and saved the owner on fuel costs. (not to mention that they made GM's "CAFE" numbers go way up)


My son inlaw was thinking about a hydrogen gizmo for his 6.0 GMC We looked at the numbers and it just does not pencil out.


This is not a question of, IF it will work and make the thing run but, instead is it cost effective.


Used veggie oil and run the thing on a genuine waste product.


I heat my entire home using a waste product. Hazel nut shells, a leftover material that must be discarded after the harvest.

Its totally Biomass and wastes nothing from the ecosystem (trees, oil etc)

I use an off the shelf Pellet stove to burn the stuff (with maybe $5 worth of mods) and to make matters even better, bought the stoves off craigs list for Cheap.


Now if you can take this concept and put it to work to make the truck run cheaply, then its a good thing.


Sadly, there is very little we have in the way of technology that can replace crude oil and its derivatives on the grand scale that the world needs.

Sure we can make alcohol and biodiesel but this is a very small scale production in comparison to whats needed.

The fellow who filters and uses Fry oil and basically gets his fuel for free is definately on the front side of the curve. Unfortunately this is a Nich item.

As soon as someone gets up into the radar, the states want taxes paid on the stuff.

Bet me, you start seeing hydrogen being used on a large scale then the Tax folks will be right there demanding that you pay up.

Now with a tax added to the mix, where is the savings now.

If you use anything as a "Motor fuel" you are supposed to pay a road tax on it.

The "backyarder" thats filtering fry oil and running his old Burb on it is "staying under the RADAR" is all.

I dont think that overall, considering all the costs, that there will be any real benefit to this setup.

Oh, and dont forget the cost of replacing all this new equipment, as it wont last forever.

Just my two cents worth.

Missy

[Mark Rinker]

I have the same response to most Jim-Crack, snake oil products that tout magical ROI...however, most are identified by their plain-clothes presentation, low cost packaging and production.

Consider the product. Look at the engineering that went into it. Digital pulse width modulation / amperage controls from the cab. A dryer to clean up the HH before it hits the intake.

Something tells me that they have found a common inefficiency to GM, Ford, Cummins diesels that can be improved. If these products were all leaving the factory in thier most efficient form, then most aftermarket products would fail - as there is nothing to improve upon.

Forget Boyle's law and parasitic drag and all that. Think efficiency increase of the pump.

- We know superchargers and turbos increase efficiency
- We know water/methanol injection can increase efficiency
- We know better lubes can increase efficiency
- Introducing an second gaseous fuel pre-MAF works. We know that, too.


Question is - is there a measureable and repeatable ROI ???

[JohnC]

Then how are a belt driven superchargers explained? Superchargers introduce parasitic drag, but their benefit is clear - the power they use is less than the power that is created as they help the air pump (engine) they are bolted to closer approach its ideal volumetric efficiency.

Not exactly. The added air provided by the supercharger allows you to burn more fuel. The added power comes from the extra fuel. The supercharger alone would decrease power, not increase it.

[Mark Rinker]

Not exactly. The added air provided by the supercharger allows you to burn more fuel. The added power comes from the extra fuel. The supercharger alone would decrease power, not increase it.

Thanks, John. I am pretty sure you just made my point for me, as that is exactly what this product intends to do...burn more fuel...remember that Brown's Gas (...HHO, Oxyhydrogen, etc.) is a mixture of both free hydrogen and oxygen molecules.

...the (underutilized) alternator alone would decrease power, not increase it.



http://en.wikipedia.org/wiki/Oxyhydrogen


From the description above, it sounds to me like the water vapor flashing over to steam that we know happens with water/meth injection, may also be a part of whats happening with Browns Gas - or Oxyhydrogen fumigation, when it is introduced into an internal combustion engine.

As a silly side note - I talked to a guy who had alot of experience building 'spud guns' - those PVC pipe contraptions that shoot potatoes. He had experimented with every flammable gas available - hair spray, ether, LPG, etc. and decided to try Brown's Gas. He reported that an equal amount of Brown's Gas would propel the potato 'into orbit' ;) when compared to the other gasses - probably because its carrying its own oxygen with the hydrogen fuel. Cylinder pressure - spud or piston, thats what makes it work.

[JohnC]

Thanks, John. I am pretty sure you just made my point for me, as that is exactly what this product intends to do...burn more fuel...remember that Brown's Gas (...HHO, Oxyhydrogen, etc.) is a mixture of both free hydrogen and oxygen molecules.



I'm not sure what point you are trying to make, but, consider this: the process by which you disassemble water into hydrogen and oxygen is exactly the reverse of the process by which you recombine the two back into water. The energy required to accomplish the first cannot be less than the energy released by the second. So, absolute best case is break even. Add to that the fact that you are converting Diesel oil into electricity (at less then 100% efficiency) to run the process and you have a system that takes more energy to run than it produces.

Now, if you could figure a way to use the alternators for braking and the energy thus produced to generate the gasses, then you could be on to something. This is how the hybrid cars gain an advantage, although, still, all that technology can't best a Volkswagen Jetta TDI...

If perpetual motion were easy we'd all be doing it... ;)

[Mark Rinker]

I'm not sure what point you are trying to make, but, consider this: the process by which you disassemble water into hydrogen and oxygen is exactly the reverse of the process by which you recombine the two back into water.

Not at all true. Don't forget the water, during combustion, flashes over to steam and creates cylinder pressure as well as a cooling effect - the same as effect we know works with water/methanol injection systems.


The energy required to accomplish the first cannot be less than the energy released by the second. So, absolute best case is break even. Add to that the fact that you are converting Diesel oil into electricity (at less then 100% efficiency) to run the process and you have a system that takes more energy to run than it produces.

What if the alternators in their factory configuration run at 25% efficiency, but asking them for another ~50amp load actually causes them to run at 65% efficiency? The pump just got more efficient, i.e. some percentage of otherwise lost diesel fuel is now being converted to a second fuel, and re-introducted into the loop...

Now, if you could figure a way to use the alternators for braking and the energy thus produced to generate the gasses, then you could be on to something. This is how the hybrid cars gain an advantage, although, still, all that technology can't best a Volkswagen Jetta TDI...

My understanding is that the Prius easily outperforms the Jetta if you are only measuring MPG. How long the batteries/motors last - and what they cost to replace is the real question.

If perpetual motion were easy we'd all be doing it... ;)

Nobody is looking for, or suggesting perpetual motion. If I were envisioning a car that ran on water only, by burning HHO and using electrical current generated by the engine to separate the water into HH and OO, then you'd be correct in saying this.

I am interested if an onboard HHO generator added to an existing diesel powered vehicle could actually overcome some factory designed inefficiencies in a similar manner to a better exhaust, properly sized turbo, better fuel map, or many other aftermarket 'whiz-bangs' that actually produce results.




(Answers above in bold italics.)

[JohnC]

Don't forget the water, during combustion, flashes over to steam and creates cylinder pressure as well as a cooling effect

Can you explain the thermodynamics of this process? (Again, best case is break even). Not sure about this part, but, I suspect since you are converting gaseous hydrogen and oxygen to gaseous water (steam) there is no phase transition, so no resultant effects, either.


- the same as effect we know works with water/methanol injection systems.

No, you're adding fuel (methanol). In a water only injection system you are converting wasted heat from the turbo. No need for all that alternator stuff to do that, though.



What if the alternators in their factory configuration run at 25% efficiency, but asking them for another ~50amp load actually causes them to run at 65% efficiency?

Still, to generate more electricity takes more diesel fuel and it is still less than 100% efficient.