PLEASE TELL ME EVERYTHING YOU KNOW ABOUT PROPANE

[Marco]

Hello fellow BOMBers,

Feeding diesel engines with propane/metane is not complicated, but can be dangerous!
I would not like to have a system that injects propane BEFORE the turbo!
Guys are you crazy? Propane has to be injected AFTER the intercooler and the heater! I know that's more complicated but MUCH safer! How much air/propane mixture will you have in the turbo/lines/intercooler? Surely much enough to cary a little bomb in the front of your truck. Only a little spark... the heater...
an... there are to many variables in the game.
Do yourself a favour and get an serious automotive regulator. This will cost you more, but you'll obtain a much saver and reliable system.
Or if you want a perfect system, build it with a gas engine style injectors( what you call the propane injector is in reality an venturi).
As far as theory goes I can't agree with HAVAC.
From what I know propane works in this way. Propane has a (much) slower burning rate than diesel or gas . This means that propane burns longer than diesel does. In other words diesel+propane gives a higher/longer compression on the piston. = More power. #ad


Go propane, but do it the save way!
Later,
Marco.

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2500, 99, QC, SB, 4x4, intense blue, Auto, 3. 54 LSD, ALL Factory options, 265 BFG, CPS Platinum running boards, Leer cap, SS fender flares, K&N , DD stage III injectors, boost module, EGT-Pyro gauges,
Rancho RS 9000 shocks, Ranch double steering stabilizer, SS Raptor front grile, custom modifyed ECM, Custom Brembo Cross drilled front discs, Brembo four piston calipers, Sorry I've surely forgotten something...

 

[illflem]

Can propane be adapted to a 12 valve system?

 

[ynot]

I'm doing mine a bit simpler and less costly. Don't worry too much about the dangers, either. Haven't blown up my grill lately #ad
BTW, must agree with HVAC on the catalyst principal. Haven't seen too many propane forklifts lately that don't have spark plugs. It relys on the combusting diesel to ignite the propane, hence the term "catalyst". Adding a higher BTU fuel to the diesel/air mix would give a higher BTU fire in the hole, and a very slight timing change (from the diesel firing first to ignite the propane), probably measured in miliseconds as an extended, not retarded, detonation. If it was slow enough it would actually push on the piston in the down stroke after TDC, thereby adding to the drive motion down (big power), as apposed to on the way up (BTDC) and relying on the "explosion" to push the piston down, as is the only way to meet emissions, which would also burn un-combusted diesel fuel, hence the drop in EGT's (I think). Anyway, I took an old "ether bomb" off of a truck motor, which has the same thread as a lantern fuel bottle (and a MAPP gas bottle. My next experiment) and an atomization nozzle, and screwed the nozzle right into the inlet elbow. Cost, $0 (most truckers have the start aid removed and discarded on the first overhaul, having never been used in the first place). The only thing to overcome now is that the new start aids deliver a premeasured dose (2. 25 cc or so) delivery, as apposed to the old ones relying on your finger on the button. Need to find and older version or take the bottom off of the solenoid trigger. My Pacbrake switch is a momentary toggle mounted on the shift lever beneath the knob, so I just put a selector switch in line on the "out" wire. One side is propane, the other is decel (hopefully won't confuse the two). Will post the results of both the upgraded solenoid and the MAPP gas when I get it done. It's not as user friendly as the ATS or BullyDog or whatever, but it does allow for propane injection at any desired RPM or boost level, and was very cost effective... T

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Tony L. Welch
Welch Performance Diesel
2001 2500 QC/SB, ETH/DEE, trailer tow, camper special, Hunter green, loaded except leather, Infinity 6 w/Alpine amp and speakers rear, Kicker sub, stainless rocker panels & fender gaurds, 12. 5x33's on Pro-69 directionals, diamond plate bed and gate liner w/rubber mats, Pacbrake (ported), compressor housing and elbow ported, intake crossover ported, K&N in factory airbox sleeved into cowl, 4" Dynomax, triple gauges (ISSPRO/ console), PE maxed, DDIII's and propane next...

 

[HVAC]

No problem on a 12v engine. You won't be able to use a PE to open the solenoid. Just use a pressure switch on the intake tract post turbo. Mine is mounted on the aluminum elbow that bolts to the intake manifold. The pressure switch is adjustable too.

 

[Marco]

Hi,

Catalysis, alteration of a chemical reaction,
through the presence of an additional substance, known as a catalyst,that remains chemically unchanged by the reaction.

How can C3H8 be an catalyst in a diesel engine??

ynott wrote:

It relys on the combusting diesel to ignite the propane. . snip
True
Adding a higher BTU fuel to the diesel/air mix would give a higher BTU fire in the hole,
Again true.

. . and a very slight timing change... snip

This is not true.

Timing is "largely" changed.
When you converse a gasser to propane ONLY,
you have to advance the ignition timing by
8-12°. (Depends upon the original timing)

This timing advance is needed to allow propane to burn completly during the "useful" range of the piston stroke.
If you don't advance the timing you'll loose about 20% of power since propane burns slower than gas.

In the diesel engine with additional propane, you obtain two things.

First, you have a more powerfull fuel mixture in the combustion chamber.
This gives you about 70% of the power increase.
Second, propane burns for a slightly longer time than diesel alone would do. This gives the remaining 30% of power increase, and a cleaner combustion. Propane burns most part of the remaining diesel fuel, which otherwise wouldn't have burnt.

For what is involved with safety, PLEASE listen to what I say.
We've got a very large number of gas cars, conversed to propane fuel, here in Italy.
I've seen too many cars burnt due to some misfunction of that system. In case of an accident... several people die in their burning cars every year, here in Italy.

Propane can be very dangerous!
The trucks and lifes are yours.
Make up your mind.....

Later,
Marco.

 

[HVAC]

Marco, thanks for adding to this topic. Please tell us what specific problems have caused the deaths, fires, or other mishaps you spoke of. Are the problems equipment or installation related? What brand equipment is typically used in Italy/Europe. Seems to me you have a large company in the Netherlands or close by that makes a lot of the equipment used on the other side of the pond #ad
I am using Impco products manufactured in southern California. They make the majority of the straight propane or dual fuel systems I've seen. I consider lpg systems quite safe when installed as per the prescribed standards.

 

[ynot]

Marco, thanks for the thoughts on safety, etc. I think this is a slightly different scenario, tho. First, the cars burning up over there are completely fueled by propane, requiring an external ignition source to fire it. Much more dangerous. Second, since you are refering to propane fueled vehicles, the timing is altered mechanically TO burn the fuel, not as a result of a spontanious reaction due to the addition of a different fuel. The timing doesn't actually change AT ALL (measurably), the duration of the burn cycle does. If you checked timing with a digital meter, you would notice no change. If you checked the engine with infrared and/or Xray, you would see a very slight detonation advance due to the fact that the fuel would fire (in thousands of a degree) faster due to the addition of a higher BTU gas than air, and the duration of burn would be, again, longer due to combustion of more fuel than normal and the slower burn of propane. Timing is not mechanically altered and the principal fuel is still diesel, once again lending cadence to the term catalyst. In all actuality, the catalyst is the diesel and the principal is the propane, in this scenario. The propane wouldn't even fire, had the diesel not burned first. Propane in itself is actually a pretty pour source for internal combustion engines. Emissions are lower because it is cleaner, but good old #2 is the highest BTU fuel on the road, barring nitromethane mixes and jet fuels, which also won't burn without external ignition sources. As for safety, no one wants to explode driving their vehicles, and propane injection is a whole lot safer then nitrous or alcohol injection, but if I'm gonna go, I'm going fast #ad
Be cool... T

 

[Chad Sheets]

OK, I'm learning here. Help me out guys. Lets go over todays lesson.

IF we add propane to our engines we need to do it so it is put into the system as close to the clyinder as possible, perhaps plumed into the block beside the boost sensor (the big 1" pipe plug) or something else close.

Now, we have propane laced air being forced into the combustion chamber. Here comes the piston up on the compression stroke. Right before TDC the injector sprays diesel which ignites everything in the cylinder. Since the propane takes a hair longer to burn, the piston gets a little extra shove it never got before as it goes down on the power stroke, plus its being pushed down a little harder than before because the propne gave us a little extra energy.

Now why are we having to play with the timing? Everything is going to be burnt before the piston comes up again on the exhaust stroke which will eliminate the need to advance timing, which would make this whole process happen sooner.

Basically the way I see this is, by adding propane you create a longer burn window, just like you would by increasing the duration of the injector spray. Only difference is if you make the injector spray last longer, you can get the combustion process to flow into the exhaust, ruining exhaust valves, turbo seals etc, because of the time required to effectively burn all that diesel fuel when both valves are closed is not enough and before you know it the exhaust valve is opening and you still have a flame trying to burn all the extra diesel you put into the cylinder. With propane you get the benefit of a longer burn window without the worry of meltdown with egt's.


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Always ready to help!
2000 2500 Red Sport quad cab, 4x4, K&N, DDI's, straight piped, boost, pyro and fuel pressure gages, custom built boost module, mean looking set of 33. 5" tires, Snap On diamond tool box, Marine Corps window sticker, Semper Fi!

1972 340 Cuda'. Original tripple black 340 car w/air! Good clean car, super stock springs, Weld Prostars, strong 340 with a 727/4000 stahl, 4. 56... . Bombs away!
NRA Life Member.

 

[Marco]

HAVAC,

Problems with propane systems are most times caused by bad service. People never change spark plugs since they don't get dirty. First missfire and you're done. Valve adjustment is also critical. Worsest thing is a bad installation, just like you guys that inject propane on the intake side of the turbo.

Let me guess, you HAVE to do so, since your regulators are opend by vaccum. You can't inject the propane anywhere on the turbo outlet side because you have positive pressure there.

Right?
This works, I don't want to discuss that. But, do you really think you're on the save side?? What if you get involved in a head- on collision? You carry a small bomb in the intercooler!
Again what about the temperature in winter?
You don't heat the regulator with the engine coolant. Have you ever seen how a iced up regulator looks like?
Those membranes can become very brittle.
Temperature is also critical for the gas pressure.
How can you adjust your systems to obtain always the same amount of propane. When it's hot outside you have a higher pressure than in the cold.
Again, what kinda pipes do you use to carry the propane from the propane cylinder to the regulator?

I'll describe shortly how "our" systems are build.
The gas cylinder is like the ones you use on RVs.
The line to the regulator is copper or better stainless. (Brings liquid propane to the regulator)(The cylinder will not ice)

Propane is gasifyed in the regulator.
The regulator, is heated with engine coolant (will not ice). The coolant is taken from the two cab heater lines.
In this way you'll have the same amount of propane all over the year (temeperature range you'll encounter). (Within a reasonabel limit)
A few words about automotive regulators.
A normal regulator delivers more propane as the pressure on it's outlet side decreases.
Most of "our" regulators can be delivered from the factory "turbo modified". This means that they deliver more propane as the pressure at their outlet side increases.
= more boost = more propane.
Now you can feed the cummins after the intercooler!
I think the best location for the mixer (injector/venturi) would be under the grid heater.
On those regulators you can adjust minimum and maximum propane flow.
Give a look at: http://www.landi. it/catalogo/gple/sgpl4e.htm
or at: http://www.tartarini. it/E_Pag1_Auto2.htm
Landi is the best one.

Ynott sez:
Timing is not mechanically altered and the principal fuel is still diesel...

I have talked about ignition timing in a GAS engine to make clear that propane burns slower. In a application like our cummins it's clear that you don't have to change ignition timing since part of the extra power is obtained from the longer burning propane.
Sure, the principal fuel is diesel.

... once again lending cadence to the term catalyst. In all actuality, the catalyst is the diesel and the principal is the propane ... . snip

Once again, you can't use the term catlysis in this case. The definition of catalysis is:

Catalysis, alteration of a chemical reaction,
through the presence of an additional substance, known as a catalyst,that remains chemically unchanged by the reaction.

In a catalytic process the catalyst has to remain chemically UNCHANGED.

If diesel is the catalyst, it has to remain chemically unchanged, do you get it back from the tailpipe?
Perpetum mobile!

If you want to use a chemical therm, the propper one might be oxidation.

Chad Sheets sez:
With propane you get the benefit of a longer burn window without the worry of meltdown with egt's.

Yeah! That's it!

Hope this helps.
Marco.

 

[Chad Sheets]

Have I passed Propane 101? Hank Hill would be proud! (Thats a cartoon over here in the states of a guy who sells propane and propane accessories in Texas).

 

[Rebel]

Was wondering if anyone knows how much pressure is availible from a propane bottle at say 50 deg. F. ? Or at what temp do the propane systems on the market cease to function properly (the non-heated variety)?
It gets way cold where I work and play, still pondering this modification.

 

[HVAC]

Your fine at 50 degrees. Propane remains a liquid/vaporizes at -44. Stay outta Alaska #ad

 

[Marco]

It's amazing,
To understand, what happens when you do modifications to your engine, exact knowledge base is needed.
Otherwise you do nothing more than guesswork.
Catalysis does not fit here, if we want to do serious information. If we want to make a comercial than it could fit.

Every time, you burn any carboneous type of fuel, in presence of oxigen, you do NOT have a catalytic process but an oxidation.
That's all.
The end product of that oxidation is:
oh well don't let's go to deep with it, you all know what's comming out of your tailpipe.

Now, if you want more power/efficency out of that given fuel you have to be able to oxidate it better/more.
In our case we add propane to diesel.
What happens exactly inside our beloved cummins in this scenario?

This is the short version.
Inject diesel into air/propane mixture, diesel ignites, propane ignites, piston travels down with more power than without propane.
The reasons for this power gain are:
Ok I'm tired read the earlier MSG.

Every thing seems fine!?
Really?

Everything has it's downside, so does diesel/propane fuelling.
When the diesel/propane/air mixture ignites you get a higher pressure in the combustion chamber. More pressure = more heat. Much more heat! Than higher the combustion temperature than better it's oxidation. = More power!
Is this good for the engine? What about the valves/pistons? They are now exposed to much higher temperatures than they were build for.
How long will valves and their seats survive that treatment. I really don't know for the Cummins.
What I know for sure is that the valves have to be adjusted more frequently.

If the combustion temperature is higher, how is it that EGT's are lower?
More pressure makes gases expand faster, than faster a gas expands than ..... temperaure. #ad

I think you've guessed it. #ad


Propane is a beast, you have to be it's master.
Later,
Marco.

 

[Marco]

It's amazing,
To understand, what happens when you do modifications to your engine, exact knowledge base is needed.
Otherwise you do nothing more than guesswork.
Catalysis does not fit here, if we want to do serious information. If we want to make a comercial than it could fit.

Every time, you burn any carboneous type of fuel, in presence of oxigen, you do NOT have a catalytic process but an oxidation.
That's all.
The end product of that oxidation is:
oh well don't let's go to deep with it, you all know what's comming out of your tailpipe.

Now, if you want more power/efficency out of that given fuel you have to be able to oxidate it better/more.
In our case we add propane to diesel.
What happens exactly inside our beloved cummins in this scenario?

This is the short version.
Inject diesel into air/propane mixture, diesel ignites, propane ignites, piston travels down with more power than without propane.
The reasons for this power gain are:
Ok I'm tired read the earlier MSG.

Every thing seems fine!?
Really?

Everything has it's downside, so does diesel/propane fuelling.
When the diesel/propane/air mixture ignites you get a higher pressure in the combustion chamber. More pressure = more heat. Much more heat! Than higher the combustion temperature than better it's oxidation. = More power!
Is this good for the engine? What about the valves/pistons? They are now exposed to much higher temperatures than they were build for.
How long will valves and their seats survive that treatment. I really don't know for the Cummins.
What I know for sure is that the valves have to be adjusted more frequently.

If the combustion temperature is higher, how is it that EGT's are lower?
More pressure makes gases expand faster, than faster a gas expands than ..... temperaure. #ad

I think you've guessed it. #ad


Propane is a beast, you have to be it's master.
Later,
Marco.

 

[AFarnham]

Rebel,
Take the temperature (F) and double it, that's about what the pressure is inside a propane system. Won't have a problem until you get to AK in Feb, like HVAC said.

If any y'all have access to National Fire Protection Association (NFPA) standards, try #58, which is for propane systems, and covers automotive applications. Technically, it's for vehicles where propane's the primary fuel source, but it has some good stuff for this type of application as well. Main focus is occupant safety, with some collision foresight.

Intake manifold injection, immediately upstream of the intake valves, has the best theoretical driveability characteristics, being easy to turn on/off quickly. Also avoids, as Marco points out, compression of a potentially combustible fuel/air mixture at the turbo.

I do fire investigations, and have seen quite a few propane forklift fires, but none of 'em were turboed. Usually the result of bad maintenance, leaking hoses, overheated motors, fuel line in contact with hot surface. Have seen my share of CNG and propane bus fires, too, for the same reasons. Bus systems always inject downstream of intercooler, like the old pressurized carburetors.

Would like to do this mod someday. Sounds like lightin' an afterburner.

 

[ynot]

When working with high HP engines, the idea is ALWAYS to burn more fuel. Whether it comes from increased turbo pressure, more fuel to have available to burn, or adding something more volatile than normal (propane, alcohol, etc. ), the end result is the same. More power. Propane burns, for this purpose, "completely", which takes longer. The extended detonation burns more diesel fuel with it. The burn is longer and more efficient, not that much harder. It's the extended detonation that reduces the exhausting of ash, acids, and particulates, thereby lowering EGT's. At this junksure, it doesn't really matter what the chemical process is called. Point is, it does occur and it does lower EGT's. When the manufacturers said in their ad's it lowered EGT's when in fact it raised them, they would be crushed by this sue happy world faster than HVAC does the 1/4 mile with it on. A good reference is page 72 of the Dec. "Four Wheeler" mag. An article by Jimmy Nylund, who is buds with Bob Jennings Dyno Shop in CA. , says, amongst other things, "Propane acts as a catalyst (he said it, I didn't. It's not worth the debate anymore and really wasn't that much fun to begin with) during combustion. This in turn creates a more complete [burn] of the diesel fuel". "... and in most cases, engine life increases significantly due to increased efficiency and reduced engine wear with lower internal engine stresses". "Both companies claim a 5 to 10 percent drop in EGT's from identical power levels. " Having reiterated on this subject enough, I'm staying out now. There are vast amounts of reference materials out there to evaluate this and other points of interest on HP. We do need to keep this in perspective, tho. I think we've said enough here to scare anyone away from propane, or even bigger tires and mud flaps for that matter. Point is, don't inject volatile substances in front of moving objects (i. e. turbo), but do it as to be evenly distributed into the cylinders, and you will see HP increases and, most likely #ad
, EGT drops without negatively effecting longevity. Nuf said. Ya'll have fun and be safe... T

 

[ynot]

Webster 101: catalyst; "a substance serving as the agent in catalysis". Catalysis; "the speeding up slowing down of a chemical reaction by adding a substance which in itself is not changed thereby". The very complex molecular structures of diesel don't change from the addition of propane, nor does the propane's. The molecules don't combine to form a new liquid/gas. The "chemical reaction" is the addition of heat/pressure to diesel to cause a structural change. The change; it blows up. Open the valve on a propane bottle. Chemical reaction: gas vaporization. Throw a match at it. Chemical reaction: much quicker gas vaporization (I understand the structural integrity of the molecule is now in question, but this is the easiest analogy I could come up with at present). Catalyst: the match. Chemical or structural change of the match at the time of reaction: none. It was burning when you threw it, and burnt more when it fell to the ground. Catalytic addition in our engine scenario; adding combusting fuels to a normally none pressure sensitive gas/liquid (propane), thereby causing propane gas detonation. The word catalyst was used in a different thread long ago pertaining to this scenario. Tho the use may obviously be endlessly debated, it fits, regardless. On the other side, it really doesn't matter what you call it. The addition of propane to a spontaneously combusting engine (i. e. diesel; it fires on it's own from compression without external ignition) is in and of itself the safest use of the gas on the road. It won't fire until the addition of a spark. Safety measures taken as per leaks or premature spark addition are the concern of the user. As for front end collisions or the like, no one will try to avoid them more than normal because they have a small canister of different fuel on board (and quite possibly it wouldn't be mounted under the front bumper anyway). In a crash scenario, there is generally less than a few seconds to react anyway, and the most common thought other than avoidance is the safety of the passengers (usually your own children. Everyone else is on their own #ad
). Propane in diesels works, as does alcohol, water, nitrous, nitro, etc. Safety is per the user. Manufactured kits are extremely safe and accident free, as evidenced by not being government regulated other than shipping or transport (i. e. the introduction in the engine is as per user). Had I actually attended high school or college, I'm sure I would have been introduced to some sort or mathematical equations to support all of this stuff. But for now, first hand experience and anecdotal evidence will have to suffice, and did for my own personal use. Been there, done that, works good, seems safe, no probs, kinda fun, etc. BTW, it was previously mentioned once again about mechanically changing timing. This is not required nor recommended. Pump it in and drive it. The changes, tho debated in form, do occur on there own. Power WILL increase and EGT's WILL drop. Thanks again for the debate... T

 

[HEMI®Dart]

Here are some pictures of HVAC`s Propane system.

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[This message has been edited by HEMI®Dart (edited 08-13-2000). ]

 

[HEMI®Dart]

HVAC or Bart,

This may be a stupid question.

Is it possible to use a hand held propane torch cylinder mounted in the engine compartment as a supply tank?

Would it last long?

[This message has been edited by HEMI®Dart (edited 08-13-2000). ]

 

[HVAC]

ZOWWY!!! That engine looks familiar #ad


Good job on the pics HEMI, I wish I could do that #ad


Your gonna send Marco over the edge with that question I'm afraid #ad
While technically you could run the system on a little one quart soldering torch tank, I urge you not to do it. Propane tanks are best installed in a well ventilated area like under the truck or in the bed. There are too many sources of ingnition under the hood to be safe. Also there is too much heat. Propane is very sensitive to heat and you could have the relief valve open which would be a catastrophe #ad
Getting back to NFPA 58 which specs propane tank installations, you can put a tank in the trunk of a car but you have to vapor proof the wall between the tank and the passenger compartment. Also you need to have a remote fill and blow-off line for the relief valve. I don't recall reading specifically about regulations governing tanks under the hood but I don't think a soldering/torch tank is DOT approved. Need to have valve protection, foot ring, approved mounting system. Better off with a barbecue tank in the bed.

If you use a vapor system you want to make sure the tank is standing up so you don't get liquid into the regulator. The converter/regulator in the pic above is designed to be supplied with liquid which is how mine is setup but like Bart said, it will work with high pressure vapor too.

On the top pic you can see the lock-off solenoid on the left, this is where the line from the tank connects. The solenoid opens when the electronics send 12vdc to in and then the regulator waits for negative pressure in the intake tract to respond by allowing the vapor to flow to the engine(I know Marco, intercooler bomb). The vapor is introduced at the aluminum collar between the K&N and the intake hose. You can see the black elbow on the converter/regulator, that is to hook the heater hose to for heat to help vaporize the liquid. I found that I had too much heat and disconnected it.

Propane is fun, just keep safety in mind #ad