Propane Injection?
08-21-2002, 10:12 PM
#1
Pro
Thread Starter
Propane Injection?
I was just talking with a buddy of mine who had seen a couple local imports which had switched over from alchohol/methanol injection systems (walls were corroding severely after not too long) to a propane with the indication that propane effectively created the same effect, with none of the corrosive properties...thought I'd drop a Q to the masses...anybody had experience with this? I'm not nearly ready to go this far, but it brought up an interesting topic, seemed interesting with no real drawbacks that we could think of...
08-21-2002, 11:37 PM
#2
Three Wheelin'
Never tried propane, but a friend of mine and I tried injecting pure Oxygen in the injection boot of a VW scirroco, DAMN that thing flew with the O2, but it blew a head gasket shortly after (cough cough, cry cry)
Christian
Christian
08-21-2002, 11:40 PM
#3
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Rennlist Member
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[quote] seemed interesting with no real drawbacks that we could think of <hr></blockquote>
Except that you have a high pressure cylinder full of explosive gas in your trunk.
I have heard a good number of the DSM tuners doing this as well with some decent temp drops, but it is tuning hell since it is a rapid combustible. (much faster than alcohol) You would need a variable nozzle to make it really work nice.
A better setup is water injection, or NOS if you want a large power gain.
Except that you have a high pressure cylinder full of explosive gas in your trunk.
I have heard a good number of the DSM tuners doing this as well with some decent temp drops, but it is tuning hell since it is a rapid combustible. (much faster than alcohol) You would need a variable nozzle to make it really work nice.
A better setup is water injection, or NOS if you want a large power gain.
08-22-2002, 01:30 AM
#4
Pro
Thread Starter
Well, NOS isn't at ALL what I was thinking...I'm not looking for power gains from the addition, more along the lines of a higher boost with lower intake temps, higher detonation resistance, without the drawbacks of cylinder wall corrosion. I suppose the H2O alone would be ok, but obviously pressurized water isn't quite up to the efficiency of the propane, which also acts as a fuel increase...quite effective from what we discussed on a stock injector system if programmed to only work on set high boost levels (perhaps set to begin operating at 15psi and above)...given that it would not only effectively richen the mixture without adding the 02 like NOS, or just cooling the mixture like H20 and being a bit of a detonation prevention tool, it would have dual benefits just like methanol without the corrosive properties. I can appreciate the issues associated with the pressurized cylinder in the trunk...obviously this would be a modification to leave off when hitting the track, but I was just tossing around some ideas since quite a few people have been talking about water injection recently. But can anyone think of things other than the flammability/pressurized gas issue that would be a serious speedbump with this. I too had heard of it from DSM sources, but I've also heard of a lot of BAD ideas from DSM lists, so that's why I thought I'd get some feedback from this list.
08-22-2002, 01:47 AM
#5
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A good Aquamist setup will drop intake temps 200 degrees or more. There are a few people running them here, hope they will speak up.
I had a '93 Talon TSI AWD pimped out, with a T04E at 24psi. My intake temp before aquamist was 330degrees after 5 seconds of boost, with it, 195. That gained me 45 hp and I never had a problem. H20 is an exellent heat absorber. Also, with the minimal amount of water that is actually used, and the aluminum construction of our motors, I think corrosion would be minimal. Methanol is a diffrent story.
I don't think that you would richen up as much as you think from propane. I am not saying it won't work, but I have not seen enough evidence to say it is better and safer than H20.
I had a '93 Talon TSI AWD pimped out, with a T04E at 24psi. My intake temp before aquamist was 330degrees after 5 seconds of boost, with it, 195. That gained me 45 hp and I never had a problem. H20 is an exellent heat absorber. Also, with the minimal amount of water that is actually used, and the aluminum construction of our motors, I think corrosion would be minimal. Methanol is a diffrent story.
I don't think that you would richen up as much as you think from propane. I am not saying it won't work, but I have not seen enough evidence to say it is better and safer than H20.
08-22-2002, 02:39 AM
#6
Pro
Thread Starter
Excellent, glad to hear it, as I'm much more confident about water...granted neither is an option I see myself needing until quite a few more mods are under the belt, but since I'll be looking for as much power as possible out of stock bottom end, things like water injection will certainly play a role down the road...
08-22-2002, 04:21 PM
#7
Race Director
That oxygen-injection scenario is actually the BEST power-producing solution, however you have to inject the proper amount of extra fuel to maintain correct air-fuel ratio. Most likely the guy burned up his engine/headgasket from being too lean and having too hot of a burn due to the extra oxygen.
Propane-injection... hmmm, interesting... I'm assuming you're injecting the propane in liquid form to take advantage of its latent heat-of-vaporization like in water-injection? I'd like to do a quantitative analysis of this to model what's really happening. So if someone could fill in the blanks for me, we can proceed:
DENSITY
water: 1.0g/ml
propane: 0.5g/ml
HEAT OF VAPORIZATION
water: 540Kcal/mole
propane: ___?
PARTIAL VAPOR-PRESSURE @ 60C
water: ___?
propane: ___?
What I'm going to do is compare what happens when you inject an equal volume of liquid water and propane into the intake-tracts after the intercooler outlet and it evaporates. This will absorb a certain amount of heat to cool the intake charge. Then the vaporized water/propane will also take up a certain amount of volume, thus displacing oxygen that could combust with fuel later in the chambers. I'm predicting that there's a balance of sorts somewhere with the degrees of cooling vs. displaced oxygen content.
And on that example of the corrosion problem with water-injection, they most likely were not doing it correctly. Probably were using a low-pressure injector like headlight-washers dumping liquid water into the intake, which doesn't vaporize, thus no intercooling effect. You really need to go with a high-pressure system like the Aquamist with computer-controlled injection that meters water-volume based upon boost-level and RPM/load.
Concluding that water-injection isn't effective based upon a few examples of a poorly-implemented systems is erroneous. That's like saying turbocharging a 944 won't work because someone tried it with a 944NA using blow-through carbs. In fact, <a href="http://members.rennlist.com/951_racerx/Ad-951differencesS.jpg" target="_blank">Porsche did it very well</a> as anyone who've driven a 951 can attest, and you just have to implement water-injection with the same level of sophistication and intelligent computer-control.
Propane-injection... hmmm, interesting... I'm assuming you're injecting the propane in liquid form to take advantage of its latent heat-of-vaporization like in water-injection? I'd like to do a quantitative analysis of this to model what's really happening. So if someone could fill in the blanks for me, we can proceed:
DENSITY
water: 1.0g/ml
propane: 0.5g/ml
HEAT OF VAPORIZATION
water: 540Kcal/mole
propane: ___?
PARTIAL VAPOR-PRESSURE @ 60C
water: ___?
propane: ___?
What I'm going to do is compare what happens when you inject an equal volume of liquid water and propane into the intake-tracts after the intercooler outlet and it evaporates. This will absorb a certain amount of heat to cool the intake charge. Then the vaporized water/propane will also take up a certain amount of volume, thus displacing oxygen that could combust with fuel later in the chambers. I'm predicting that there's a balance of sorts somewhere with the degrees of cooling vs. displaced oxygen content.
And on that example of the corrosion problem with water-injection, they most likely were not doing it correctly. Probably were using a low-pressure injector like headlight-washers dumping liquid water into the intake, which doesn't vaporize, thus no intercooling effect. You really need to go with a high-pressure system like the Aquamist with computer-controlled injection that meters water-volume based upon boost-level and RPM/load.
Concluding that water-injection isn't effective based upon a few examples of a poorly-implemented systems is erroneous. That's like saying turbocharging a 944 won't work because someone tried it with a 944NA using blow-through carbs. In fact, <a href="http://members.rennlist.com/951_racerx/Ad-951differencesS.jpg" target="_blank">Porsche did it very well</a> as anyone who've driven a 951 can attest, and you just have to implement water-injection with the same level of sophistication and intelligent computer-control.
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08-23-2002, 12:05 AM
#8
Pro
Thread Starter
danno, the corrosion concern wasn't so much for water but for the water/methanol mixture that's more common and more effective as a cooling tool, but also not nice to cylinder walls...I wasn't really putting a straight water injection into consideration as of the first post...I was more considering direct injection systems that were space and weight efficient...
As to the questions about the propane, keep in mind as well that the systems being used are all based on pressurized (buy a can at your local gas station) propane tanks (obviously not nearly as safe as water, but volumetrically much more efficient than water in a tank)...the added benefit of course, aside from the richening effect of adding propane to a combustible mixture, is that the propane would be compressed liquid propane in a tank, which, upon release and expansion would become a gas and absorb energy from the intake tract due to the sudden expansion of a pressurized system...so you'd get significant cooling over water only, as well as the added fuel...'course, this is all me speculating based on my thermo classes that I took and promptly forgot 8 years ago
As to the questions about the propane, keep in mind as well that the systems being used are all based on pressurized (buy a can at your local gas station) propane tanks (obviously not nearly as safe as water, but volumetrically much more efficient than water in a tank)...the added benefit of course, aside from the richening effect of adding propane to a combustible mixture, is that the propane would be compressed liquid propane in a tank, which, upon release and expansion would become a gas and absorb energy from the intake tract due to the sudden expansion of a pressurized system...so you'd get significant cooling over water only, as well as the added fuel...'course, this is all me speculating based on my thermo classes that I took and promptly forgot 8 years ago
08-23-2002, 01:10 AM
#9
Race Director
"propane tanks (obviously not nearly as safe as water, but volumetrically much more efficient than water in a tank)."
How do you come to this conclusion? Without specific numbers, I can't comment one way or the other. I'm not really saying "yes it is" or "no it isn't", there is actually that third position of "I don't know" or "I don't have enough information to comment"
"the propane would be compressed liquid propane in a tank, which, upon release and expansion would become a gas and absorb energy from the intake tract due to the sudden expansion of a pressurized system"
This is exactly the same mechanism that is used in water-injection.
"so you'd get significant cooling over water only, as well as the added fuel"
Well.. again without actual numbers, like heat-of-vaporization, I can't really say one way or the other whether a given-volume of vaporized propane or water would cool a pre-determined volume of air. The answer somes from how much heat energy is absorbed when water evaporates vs. when propane evaporates.
And the 'added fuel' can be a detriment. The main goal in engine-efficiency is to get more oxygen molecules into the engine; you can ALWAYS add more fuel. But more fuel, doesn't mean more power. Fuel will only combust with however many oxygen molecules you have in the chamber, the rest cools the mixture and goes out the tailpipe. So the idea behind intercooling, water/propane injection is to cool the mixture so that it's denser, thus you'll have more oxygen molecules injested per piston stroke.
This is the same issue with water-injection that was brought up a while ago. Sure you can inject even more water to get a 200-degree reduction in temperatures, but the extra water displaces so much air, that your power may actually be less than just injecting enough for a 100-degree reduction.
We're really talking about two completely different things here. You are saying yes/no, black & white qualititave statements and conclusions about water vs. propane injection. And I'm using quantitative analysis, shades-of-grey, it-depends type of statements. And since I don't have the actual numbers to use, I'll stick to my position of "there's not enough data presented here to say definitely that one or the other is desireable". It may even be a case of one being better at certain applications and the other for another.
So please, fill in the above blanks for me.
How do you come to this conclusion? Without specific numbers, I can't comment one way or the other. I'm not really saying "yes it is" or "no it isn't", there is actually that third position of "I don't know" or "I don't have enough information to comment"
"the propane would be compressed liquid propane in a tank, which, upon release and expansion would become a gas and absorb energy from the intake tract due to the sudden expansion of a pressurized system"
This is exactly the same mechanism that is used in water-injection.
"so you'd get significant cooling over water only, as well as the added fuel"
Well.. again without actual numbers, like heat-of-vaporization, I can't really say one way or the other whether a given-volume of vaporized propane or water would cool a pre-determined volume of air. The answer somes from how much heat energy is absorbed when water evaporates vs. when propane evaporates.
And the 'added fuel' can be a detriment. The main goal in engine-efficiency is to get more oxygen molecules into the engine; you can ALWAYS add more fuel. But more fuel, doesn't mean more power. Fuel will only combust with however many oxygen molecules you have in the chamber, the rest cools the mixture and goes out the tailpipe. So the idea behind intercooling, water/propane injection is to cool the mixture so that it's denser, thus you'll have more oxygen molecules injested per piston stroke.
This is the same issue with water-injection that was brought up a while ago. Sure you can inject even more water to get a 200-degree reduction in temperatures, but the extra water displaces so much air, that your power may actually be less than just injecting enough for a 100-degree reduction.
We're really talking about two completely different things here. You are saying yes/no, black & white qualititave statements and conclusions about water vs. propane injection. And I'm using quantitative analysis, shades-of-grey, it-depends type of statements. And since I don't have the actual numbers to use, I'll stick to my position of "there's not enough data presented here to say definitely that one or the other is desireable". It may even be a case of one being better at certain applications and the other for another.
So please, fill in the above blanks for me.
08-23-2002, 01:34 AM
#10
Pro
Thread Starter
"How do you come to this conclusion? Without specific numbers, I can't comment one way or the other. I'm not really saying "yes it is" or "no it isn't", there is actually that third position of "I don't know" or "I don't have enough information to comment" "
Again Danno, remember I'm basing this on my memories of a thermo class that I also rated a meagre C- in about 8 years back, before I went to the dark side, abandoned Engineering for English/Literature, so these are vague memories, not scientific, quantified statements...however, unless I'm totally mis-understanding the water injection principal, even with some of the more advanced systems like Aquamist, you're still starting with an atmospheric tank of water, which is then pressurized and forced through a 'mister' of some sort...effective, and yes, in theory you're right, the end effect is still a liquid being turned nearly to gas/vapor...however, the point I was making is the the propane is pre-pressurized in the tank, thus the system inherently absorbs energy/heat as it expands leaving the tank, which would, to me, make it more effective as a cooling function than the water...perhaps this is erronious, but in our discussion this was one of the principal benefits we saw over straight water injection...
as for the added fuel issue, recognizing that boost is something that can be turned up without adding injectors and chips, I was thinking of it more as a 'low buck' solution down the road, possibly (I stress POSSIBLY since I'm just talking out of my a$$ about theoreticals as the mild amount of added fuel and mild amount of cooling would effectively bring the mixture just a hair below what I see as being a moderate detonation threshhold in a system running simple mods...just a simple way with a nice throttle port injector to drop temps, gain a little HP from that avenue, and add just a hair of fuel to richen up the mixture a tad...obviously it would be fairly pointless running some of the MAF, MAP, or standalone systems out there with programmability, but for those of us seeking to spend less and gain a bit of reliability (possibly) with a bit of power, it might be a feasible option.
I too hope to see someone with the chemical background I lack to post some of the info on propane vs water as well, as I agree, that will really be the test of whether one is truly BETTER than the other...at this point I'm just wondering if one might not be easier (no need for a pump or pressurizer for the system, and it comes in its own reservoir) and a hair more efficient...
Again Danno, remember I'm basing this on my memories of a thermo class that I also rated a meagre C- in about 8 years back, before I went to the dark side, abandoned Engineering for English/Literature, so these are vague memories, not scientific, quantified statements...however, unless I'm totally mis-understanding the water injection principal, even with some of the more advanced systems like Aquamist, you're still starting with an atmospheric tank of water, which is then pressurized and forced through a 'mister' of some sort...effective, and yes, in theory you're right, the end effect is still a liquid being turned nearly to gas/vapor...however, the point I was making is the the propane is pre-pressurized in the tank, thus the system inherently absorbs energy/heat as it expands leaving the tank, which would, to me, make it more effective as a cooling function than the water...perhaps this is erronious, but in our discussion this was one of the principal benefits we saw over straight water injection...
as for the added fuel issue, recognizing that boost is something that can be turned up without adding injectors and chips, I was thinking of it more as a 'low buck' solution down the road, possibly (I stress POSSIBLY since I'm just talking out of my a$$ about theoreticals
as the mild amount of added fuel and mild amount of cooling would effectively bring the mixture just a hair below what I see as being a moderate detonation threshhold in a system running simple mods...just a simple way with a nice throttle port injector to drop temps, gain a little HP from that avenue, and add just a hair of fuel to richen up the mixture a tad...obviously it would be fairly pointless running some of the MAF, MAP, or standalone systems out there with programmability, but for those of us seeking to spend less and gain a bit of reliability (possibly) with a bit of power, it might be a feasible option.I too hope to see someone with the chemical background I lack to post some of the info on propane vs water as well, as I agree, that will really be the test of whether one is truly BETTER than the other...at this point I'm just wondering if one might not be easier (no need for a pump or pressurizer for the system, and it comes in its own reservoir) and a hair more efficient...
08-23-2002, 01:43 AM
#11
Burning Brakes
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I have not seen this on gas engines personaly, but I have seen and do know the diesel guys like this mod. There are some 16 wheelers out there running this setup. Its a big power gain for them, and if done right, its like running NOS on those trucks.
Thats it for my input.
:-)
Thats it for my input.
:-)
08-23-2002, 01:47 AM
#12
I believe H2O has one of the highest heat of Vaporization due to the hydrogen bonding. Here is the info on Propane.
PHYSICAL CONSTANTS (Propane):
Molecular Weight: 44.096
Latent Heat of Vaporization @ b.p.: 101.76 cal/g
Vapor Pressure @ 70º F.: 109 psig
Latent Heat of Fusion @ m.p..: 19.10 cal/g
Specific Volume @ 70º F., 1 atm.: 8.5 cu.ft/lb Specific Heat, Gas @ 60º F., 1 atm. Cp: 0.3885 cal/(g)(ºC)
Boiling Point @ 1.0 atm. : --43.7 ºF Specific Heat, Gas @ 60º F., 1 atm. Cv: 0.3434 cal/(g)(ºC)
Freezing Point @ 1 atm. : -305.84 ºF Specific Heat Ratio, Gas @ 15º C., 1 atm., Cp/Cv: 1.131
Specific Gravity, Gas @ 60º F., 1 atm. (Air = 1): 1.5503 Solubility in Water @ 17.8º C., 1 atm. : 6.5 vol/100 vol H2O
Density, Gas @ 0º C., 1 atm.: 1.97 g/l Autoignition Temperature.: 874°F
Density, Liquid @ 20º C 0.5005 g/ml Surface Tension @ -50 ºC.: 16.49 dynes/cm
Critical Temperature: 206.2 ºF Viscosity, Gas @ 60ºF., 1 atm. : 0.008029 centipoise
Critical Pressure: 617.4 psia Heat of Combustion, Gas @ 60ºF.: 2563.3 BTU/ft3
Critical Density: 0.220 g/ml
PHYSICAL CONSTANTS (Propane):
Molecular Weight: 44.096
Latent Heat of Vaporization @ b.p.: 101.76 cal/g
Vapor Pressure @ 70º F.: 109 psig
Latent Heat of Fusion @ m.p..: 19.10 cal/g
Specific Volume @ 70º F., 1 atm.: 8.5 cu.ft/lb Specific Heat, Gas @ 60º F., 1 atm. Cp: 0.3885 cal/(g)(ºC)
Boiling Point @ 1.0 atm. : --43.7 ºF Specific Heat, Gas @ 60º F., 1 atm. Cv: 0.3434 cal/(g)(ºC)
Freezing Point @ 1 atm. : -305.84 ºF Specific Heat Ratio, Gas @ 15º C., 1 atm., Cp/Cv: 1.131
Specific Gravity, Gas @ 60º F., 1 atm. (Air = 1): 1.5503 Solubility in Water @ 17.8º C., 1 atm. : 6.5 vol/100 vol H2O
Density, Gas @ 0º C., 1 atm.: 1.97 g/l Autoignition Temperature.: 874°F
Density, Liquid @ 20º C 0.5005 g/ml Surface Tension @ -50 ºC.: 16.49 dynes/cm
Critical Temperature: 206.2 ºF Viscosity, Gas @ 60ºF., 1 atm. : 0.008029 centipoise
Critical Pressure: 617.4 psia Heat of Combustion, Gas @ 60ºF.: 2563.3 BTU/ft3
Critical Density: 0.220 g/ml
08-23-2002, 02:53 AM
#13
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Good info on the propane, please note that yes alcohol/water has been shown to be quite corrosive to engines. Buick experimented with this in the T-types. check these links out...
<a href="http://www.importpoweronline.com/propane.html" target="_blank">http://www.importpoweronline.com/propane.html</a>
and also
<a href="http://ubb.turboford.org/ultimatebb.php?ubb=get_topic;f=1;t=013700" target="_blank">http://ubb.turboford.org/ultimatebb.php?ubb=get_topic;f=1;t=013700</a>
<a href="http://www.importpoweronline.com/propane.html" target="_blank">http://www.importpoweronline.com/propane.html</a>
and also
<a href="http://ubb.turboford.org/ultimatebb.php?ubb=get_topic;f=1;t=013700" target="_blank">http://ubb.turboford.org/ultimatebb.php?ubb=get_topic;f=1;t=013700</a>
