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hey guys i would but...my car is off the road for the messy maine winter. i have the engine out right now and i am putting in a 60-1 t3/t4 and am going to attempt to run it with propane and a supra SMIC...going to really put this propane to the test. if i dont get the street results i want i am going to go to a FMIC + propane. the only results i can provide from the 16G is the amount of fuel i pulled, i went from +14 in the high rpms to -7 and ran an additional 4-5 pounds of boost. promising, but we'll see what it can do to the hot t3/t4 air.

does anyone know at what temperature propane ignites? the exhaust side of the turbo gets awful hot...but if it is no hotter than the ignition temp of the propane i dont see a problem with injecting pre turbo, but i also dont see a great benefit except for mixing the air and propane better. i guess testing is all we can do, it sounds like it is fairly complex to calculate it mathmatically with all the velocity and volume variables. i would be spraying in each location on my new setup with temp probes and all to get some real answers, but it is going to be a little while.
 
joereitman said:
I found this was an interesting technical thread on propane injection:
http://www.eng-tips.com/viewthread....iewthread.cfm?SQID=24712&SPID=71&newpid=71&page=1&CFID=5969594&CFTOKEN=45251682

Unfortunately, it raises as many questions as it answers...

Joe

this is a very interesting post. but i diagree with a few points, i believe they are over guessing the amount of proane that is injected. it is no where near 20%. with calculation such as joereitman suggests, 1:154, the amount of air the propane is displacing does not touch the amount of air an extra 4 pounds of boost can bring into the cylinders. i ran IPOs system for about a month of daily driving and did not drain a 5# bottle. i probably used close to 50 gallons of gas in that period...5# to 50 gallons is a small propaine to gasoline ratio. and by using o2 voltage i do not see how we can be drowning our engine in fuel to deter knock.

without some dyno tuning/results, more data logs, and some intake air temps i dont believe anyone should jump to any conclusions. we are all using theory as of right now, theory should not be incorrect but we need more information. keep it coming.


EDIT***ah shit, i just posted over there and it posted under joereitman's name. sorry man, i didnt know it was doing this. :-/
 
This thread makes me seriously doubt the conventional wisdom that propane vapor comes out of the tank at minus 45*:
http://www.eng-tips.com/viewthread....wthread.cfm?SQID=20358&SPID=391&newpid=391&page=1&CFID=5969594&CFTOKEN=45251682

It is true that propane liquefies at minus 45*. But, the bottles used in the kits currently marketed are designed to provide VAPOR, not liquid. They draw off the top of the cylinder, from the vapor, not the liquid. To confirm the temperature of the propane leaving the tank, I opened the valve of the 5 # tank wide open (outside of course, up on the edge of the porch roof of my workshop, so the heavier propane would drop and I would not be breathing propane) and watched the thermometer drop from ambient 55* to 10* over the span of about a minute. It would not drop past 10*.

I repeated this with the full 25# tank, but using the LH thread to ¼” NPT adapter since the 25 is the new style and does not flow gas without the adapter in place. I kept the valve wide open for over 2 minutes and could not get the thermometer to drop below 27*. Nor did the thermometer ice up like it did from the 5# tank. I attribute this to the smaller orifice of the adapter- can anyone think of any other reason?

In the 25# experiment my finger was partially in the path of the propane and I assure you I was in no danger of frostbite. It felt cool, but not bitter cold like minus 45 would. I pressed my finger against the adapter opening and was able to block the flow without great difficulty. It felt like maybe 60 to 80 psi- that could be calculated fairly easily if I had the right formula.

This “experiment” seems to indicate that any claim that vapor propane exits the tank at minus 45 is probably inaccurate, as the above thread leads me to believe. Thus, the cooling benefits of vapor propane seem to have been overstated. However, I do not doubt the cooling benefits of liquid propane- the 5# tank had a layer of frost on the bottom half from the liquid inside converting to vapor, about 5 minutes after experiment number one.

So now I continue to wonder what is creating the increased resistance to detonation…

Any thoughts?

Joe
 
P.S.-

This was a potentially DANGEROUS experiment that was not done anywhere near any source of spark (Light switch, thermostat, metal scraping against metal or stone, etc) , flame or intense heat. I will not be repeating this experiment. It was a one shot deal to add to the collective knowledge of the DSM community, and I hope no-one else tries to duplicate it! The safer way to measure temperature would be with a sensor in an existing injection system.

Thanks,

Joe
 
this is interesting...if the temp drop is not killing knock what is? thank you for putting your life at risks with these test the info is greatly appreciated :D what if we invert the propane tank to get any of the liquid to the nozzle, maybe it is similar to co2 in that way. do they sell any siphon tanks? i need to get my car on the road so i can run some real tests, damn.

my physics teacher brought up some interesting points today. he said that air is very easily heated but harder to cool, and if i was able to drop the pre turbo intake air 10* the post turbo drop would only be about 3*. he said the fuel would atomize a lot better pre turbo but post turbo there are a lot more air molecules for the propane to react with netting a better drop in temperature. he also said the greater the temperature of the air the greater the delta temp. try taking a bowl of water at room temp then dumping a bunch of ice into it, notice there is not a fast change in temperature. now take hot faucet water and dump ice into it, the temperature is going to drop rapidly and only begin to slow as it reaches a closer to ambient temperature.

but after all that babbling we dont even know if the temperature is what is giving us the results we are getting. if not what is?
 
I still havn't found any solid data that this works better than water injection.. Well maybe it works better than pure water injection, but the buick guys seem to be getting good result injecting a high mixture of alcohol.
 
i dont think anyone can answer that right now...but in my oppinion it is safer (for the engine) than water since it is another fuel and you can not risk injecting to much. and you can watch EGTs which will tell you how the mxture you are injectng is effecting the enigne unlike water that can not be viwed on a gauge for such things as hydro lock. when all our data is collected i would not hesitate to move on if i do not get favorable results.
 
Greg- some of the straight propane systems are liquid feed, but I think they generally use a vaporizer before injection. The tanks we have are not at all designed for liquid flow, from what I have read. I think they may be unsafe used that way.

I have some reservations about your physics teacher's statements based on some research I did on the gas laws a while back. See http://www.dsmtalk.com/forums/showt...wthread.php?s=&threadid=60328&perpage=40&highlight=charles and law&pagenumber=2

Warning- it is long and boring- I got a little carried away...

In any case it seems there are some benefits to pre turbo, although it does seem a greater delta T will yield more heat exhange/absorption. But, if the propane is not giving us the temp drop we thought it did and it is being injected in small quantities, what is causing the decreased detonation?

BTW, as to your statement_ "i ran IPOs system for about a month of daily driving and did not drain a 5# bottle. i probably used close to 50 gallons of gas in that period...5# to 50 gallons is a small propane to gasoline ratio. "

How much were you boosting then? We would have to look at your gas consumption only while boosting to compare to propane used to get an idea of ratio of gas:propane. Maybe you were boosting almost all the time :)

Jeremy- I think the GN boys like alky because when they tried dumping enough water to prevent detonation in a 3.8 litre engine at 20+ psi the water was killing power. It has unlimited Octane, but it does not produce any BTU's. They were literally drowning their engines as I understand it, so they went to alky which is both combustible and and also absorbs heat well. At least that is my understanding based on some threads I read in the turbobuick forum a while back. A lot of folks like a 50/50 mix. Jay Carter, who posts over there regularly and who has designed a successful alky system and now a high end propane system, readily acknowledges that more boost does not always equal more power. Thus, I still await Erik's dyno runs. Hopefully soon...

Thanks,

Joe
 
i am watching the patriots game right now so i cant read that post, but i will get around to it in the next day. and i am retarded, these tanks can only be used in the upright position...but maybe a liquid tank with a vaporizer is something to look into. when i drive i boost a lot, i am by no means easy on the gas and only get about 16mpg around town...i gotta admit i spool her at about every stop sign. i was running 20psi on a big 16G at the time with the IPO system open about 3/4 of a turn.
 
Slightly off topic : I am using water injection (roughtly 16-20% water to fuel ratio) right now and the result aren't too impressive, I'm estimating maybe it kill knock from 15 count down to 9, at the same boost level. And that is real knock, and I'm really pushing the limit of the 91 octane at times.

I can imagine the air fuel mixture really wants to explode before the spark fire, probably due to hot spots or carbon.

I did mixed in some 100 octane (R+M/2) one day giving me an effective octane mix of around 95 octane, and I was able to raise boost about 3 PSI before similar counts of knock happens.

I did give some thought into adding some more water, but I decided it would just be taking up space, I estimate if I run 25% water to fuel ratio, in the best case probably only let me raise boost 1-2 PSI.

Now the Buick results, seems to be able to raise boost from 15 PSI to 22-24 PSI, that is fairly impressive. Most of the tests they kept the chip the same so the timing map stayed consistent, pretty good tests IMO.

I did exchange a few e-mails with Jay Carter, he came from the world of alcohol/water injection. He basically told me that propane so much better; and he had been playing with WI for a very long time. Not that he would be baised or anything, right ;)

So I would say my car is "super knock prone" and only real octane can quench it, if this works on my car then it will probably work on everyone else's :)
 
On that point, I had some trouble with nock as well until recently. In the process of changing the head gasket I notced my pistons were covered in 1-2mm of garbage, and the valve reliefs were entirely filled in. Makes me wonder how the valves never hit, especially since I had hit 10k rpm by accident not too long ago... (doh!) The motor was built ~9 months ago. After 3 hours of shipping the crap off them, I was surprised by how hard the car pulled. Logging showed tht all of my knock was gone. On a dyno run a week prior, I was getting as high as 5 degrees of timig pulled when I made the 326 whp on pump. Street drving seemed a bit better at 3 degrees of knock retard on most pulls. I was able to turn the boost up as high as 22-23 psi, take out 12% fuel, and advance timing plus 7, or 23-24 degrees total advance with no knock (DSMlink). Some people say that swapping to the metal HG did it, but the difference in thickness between the two gaskets (minimal) is othing compared to the 1-2mm of stuff on the psitons, which was bad for both compresion and heat retention.

Just some food for thought...
 
I guess I'll try the propane first. If that doesn't work then it's time to pull the head and do what you did.

I have an idea to install the vapor line after FMIC but before my intake air temperature probe. I'm not expecting much in terms of super cold air, but if the temperature actually drops below ambient under boost, that would be really interesting.
 
joereitman said:
I wonder how much MCCC would clean off the carbon buildup that was that bad? http://www.dsmtalk.com/forums/showthread.php?s=&threadid=5378&highlight=mccc

I guess it would take several applications.

Joe
That just seems like such a PIA. I got these 2 cans of stuff, made by BG, that you mist into the intake with the engine running about 2500 RPM. I would say it worked; I had to reset my idle after I did it. It is supposed to clean out your intake manifold, valves, and pistons. I am a big believer in BG products, so I trust it to do what it says.
 
joereitman said:


"The temperatures for spontaneous combustion of hydrogen, methane and propane are 585°C, 540°C and 487°C respectively"
Per http://www.hydrogen.org/Knowledge/w-i-energiew-eng2.html

487*C is 908.6*F per http://cic.vtt.fi/java/javascript/celcius.html

Joe

:eek: oh my, im not going to be spraying propane anywhere near my turbo i guess. i bet with a small explosion in your turbo you could blow the insides out real good. if you think about it your turbo could get pretty close to that temperature i bet, exhaust temps in the manifold are 1600f...
 
Center section is both oil and water cooled. I can touch the compressor housing after spooling without getting burned, even when turbine is red hot. But as a practical matter, the closer you can inject to the TB, the safer, to avoid a combustible mix in the licp, ic and uicp.

Joe
 
I don't think the propane is going to combust in the intake stream, else the turbo diesel guys wouldn't do it.

HOw do I explain it? Its simple really. The propane doesen't spend enough time in the compressor to actually absorb its heat before its in the UIC and into the engine. Its like touching a hot stove real quick with your hand. As long as you don't hold it their for to long, your not gonna get burnt.
 
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