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Engine Specific Info and Questions => IDI Engine => Topic started by: molgrips on October 23, 2008, 05:48:59 am
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Anyone know what effect running on vegetable oil has on EGTs?
I seem to remember that some oil has higher cetane rating and some lower. Is it the case that higher cetane value = higher EGT?
Since I am also advancing timing slightly more than normal, does that also increase EGT? Seems to me it should decrease it, theoretically...
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WVO (waste Veggie) usually has a lower centane (40 - 50) vs. diesel ( >47 USA) and lower energy density, but hey, its free and GREEN !!
http://www.poel-tec.com/english/index.php
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last time i ran veggie i seemed to get better mileage with my car... however it was highway for the most part... car ran smoother too! it was about 60/40 mix or maybe even a bit more veggie than that...
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Of all the conversions i have done in the past 2 1/2 years, it seems that TDI's get better milage and IDI's get slightly less -maybe 2-5 % and about 7-10 5 less torque. The differences seem to be very small and unless you can check over big distances, it basically the same. My transporter difinitely runs rougher at idle, but i don't care because it cost me $1 to go 2400 kms.
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If I could find a supplier for the WVO I would be all over it!
Less mileage from a free fuel source is a moot point.
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last time i ran veggie i seemed to get better mileage with my car... however it was highway for the most part... car ran smoother too! it was about 60/40 mix or maybe even a bit more veggie than that...
My brother runs 50% waste ATF through both of his 24v Cummins. He pumps the stuff through a clear whole house water filter with a 5 micron filter... He tried much higher amounts of trans fluid, but said the exhaust started to smell too much.
I was thinking of using the same device for WVO and mixing it 50% with diesel in my tank... any issues in the winter with waxing when you mixed your WVO and diesel ?
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I had an EGT in my former N/A Rabbit which was the first I ran on WVO.. Never really saw any signifigant change in egts on that one.. Maybe a 50 degree variance between diesel and veg.. Interestingly enough this would vary pending on where I was getting my oil from at the time...
I been burnin WVO for about 6 years now.. Maybe a slight power decrease.. I drive the same route daily which includes a small mountain... Can;t say that I notice much of a difference on diesel or WVO as I still can;t pull that hill any faster than 55mph.. AS far as MPG's I checked my milage on a 250 mile trip and pulled 46 on WVO.. That was at an average speed of about 70 out on the highway... On diesel I get about 49 mpg but that's not all highway driving either.. Not to mention my driving habits are not necessarily the oriented towards maximum economy.. :twisted:
20% veg is about the max you'll want to go in warmer weather.. As far as a Cummins that may be a bit more receptive to higher mixes but the generally most stick to 20-25 % veg.. Too much veg and the stuff won;t spray outta the injectors properly unless it's heated... When diesel doesn;t spray out the injectors properly (IE bad injector) It'll leave alot of carbon that will pretty much blow outta there with some spirited driving..... However the glycerine in WVO leaves a really hard deposit that requires dissassembly and a scraper/screwdriver/chisel to remove..
Another thing is that the vehicle needs to be driven frequently.. The WVO will settle out of the diesel to the bottom of the tank if left sit for several days...
Just as an FYI here's the cetane ratings on several different plant based oils
Linseed 27.6
Bay 33.6
Walnut 33.6
Cottonseed 33.7
Almond 34.5
Peanut 34.6
Wheat 35.2
Poppyseed 36.7
Sunflowerseed 36.7
Rapeseed 37.5
Corn 37.5
Soybean 38.1
Sesameseed 40.4
Safflowerseed 42
Castor 42.3
Olive 49.3
Hazelnut 52.9
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it seems that TDI's get better milage and IDI's get slightly less
Could that be because the TDIs are using fuel heaters to thin the fuel and hence getting a better spray pattern?
I've run my car on 100% veg oil for a few tanks and it drives exactly the same as it does on diesel - love that IDI engine.. I'm now experimenting with blends - apparently 10% petrol thins veg oil down to the consistency of diesel at 4 degrees C or so. I'm using about 15% petrol at the moment in case the temperature drops lower than that, not that it's likely where I live at this time of year. Hardly ever gets much colder than that even in winter.
At say 6 or 7 degrees, the car starts immediately, and you only get a tiny bit of misfiring for the first few seconds. After that the smell is the only thing that's different :)
I'm gonna pull the injectors soon and get them serviced - I'll look out for any hard deposits. Dunno how old the nozzles are but the car's done probably at least 10k miles on veg, possibly much more.
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TDI's have a fuel temp sensor and my engineer guy seems to have checked out the values with both fuels. I would thing that the ecm will then compensate by adjusting the fuel map and timing.
I have checked it out when i had mine and sure enough fuel flow was the same.
Be careful with blending them in you tank. The problem is that over a long time it'll lead to injector coking and and cylinder wall glazing. The way around it is to only use WVO or VO once the motor is warm i.e. using a 2 tank system and properly heating the VO.
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last time i ran veggie i seemed to get better mileage with my car... however it was highway for the most part... car ran smoother too! it was about 60/40 mix or maybe even a bit more veggie than that...
My brother runs 50% waste ATF through both of his 24v Cummins. He pumps the stuff through a clear whole house water filter with a 5 micron filter... He tried much higher amounts of trans fluid, but said the exhaust started to smell too much.
I was thinking of using the same device for WVO and mixing it 50% with diesel in my tank... any issues in the winter with waxing when you mixed your WVO and diesel ?
i only ran the WVO in the summertime. it idled very smooth, maybe because my timing is a little too advanced, and the veggie retards the timing (i wish there was a way for us IDI guys to adjust timing on the fly like the TDI guys). i'm probably going to rig up a system to pre-heat the veg, or buy those injector line heaters. merc benz guys run 100% WVO or SVO in the pumps without pre-heating with good results.
i thought that glycerine is the leftovers of making biodiesel and that what is really in the veg is glycerides?
EGR will probably kill your motor if you run veg in it without properly pre-heating IMO. another good reason to only switch over to veg when the motor is up to operating temp.
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Many have reported higher EGT's on veg, I'm not sure why this is.
The reason they are quieter on veg is due to lower cetane rating I think, causing the car to run like the timing is retarted. Perhaps some of the noise is reduced due to greater lubricity, but the burn is noticeably different too.
Unless you live in a very warm climate, I would not consider one tanking. An SVO blend may be OK in an IDI in hot weather, but definitely not in cooler weather. Personally, I would not one tank it in any weather, starting on cool veg will cause coking, glazing and will contaminate engine oil, also just overall rougher and smokier at start up.
Two tank systems are the way to go in my opinion, I have logged a good 200K veg miles in the past 8 years with few problems, even on the coldest of days.
I can see running one tank on some beater in a hot climate, but not on a project car that I love and want to keep.
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i thought that glycerine is the leftovers of making biodiesel and that what is really in the veg is glycerides?
The glycerine is indeed a by product of making biodiesel... The process of making biodiesel is breaking down the triglycerides and letting them settle out. With SVO and WVO the glycerine is still in the fuel.... And if not burned up properly it make one heck of a mess in the engine...
I only ever ran 2 tanks of veg diesel mix during the summer on my 1.6.. It was a bit unhappy on cool mornings so I just caved a built a 2 tank system.... The other benfit with the 2 tank system is if you do have a freak cold snap you still have the diesel to fall back too.. IF You got one tank and the fuel is Jello you be screwed..
THe one thing that there has been alot of debate about is having the fuel TOO hot.. Generally most information just simply states that it needs to be heated to about 170 deg F.. But with the heat in the tank, and the heat exchanger I can easily see the oil hit 200-210 deg F.. Dunno what this does for the seals on the pump.. I got 125,000 miles on the old Rabbit with no trouble... My current car has a farily recently rebuilt pump and about 45,000 miles on it with no trouble yet...
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What about waste motor oil anyone running it?
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A good friend of mine ran several tanks through his Benz 300D a few summers ago... Probably only a few thousand miles as it REALLY smoked.. It seemed to run the same as always, but I swear you can burn about anything in an old Benz..
He burned it in in the same manner as one would burn WVO in a 2 tank system... It was filtered and dewatered just like he does with WVO.. Although I had worries about any antifreeze that might have still been lurking in the stuff...
I've burned waste motor oil, and waste veggie oil in my waste oil furnace to compare.. the WVO leaves far less ash and crap in there
Like was said before I would probably be more inclined to run it thru an old beater, and not something you are planning on keeping forever.. I would imagine it's got to leave all sorts of soot and carbon in there..
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i was figuring that. We go through about 1000 gallons of waste a month where I work. So I was wondering how hard it would be to run it.
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This has been discussed a bit on Vortex and other places... Kinda getting curious about the long term results myself... With access to that amount of old motor oil I can see why you might consider it....
I usually never have enough of the stuff to heat the place for the entire winter, but I just may have to get my fingers on a beater and see what the long term effetcs are... I can always burn some WVO if need be.. 8)
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Yeah one of the perks of the job I guess LOL although they all think Im crazy for wanting it.
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i was figuring that. We go through about 1000 gallons of waste a month where I work. So I was wondering how hard it would be to run it.
can i have some of that??? :shock:
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can i have some of that??? :shock:
X2 !!! With that amount of oil available I'd be building my self another waste oil furnace to heat my house, and still have tons to spare.
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some day i will mess with veg oil system!
Duane
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some day i will mess with veg oil system!
Duane
I've found it to really be worth the fuss.. 1800 miles to 10 gallons of diesel in the summer months :shock: Winter months I only get about 1000 miles to a tank of diesel... After hours of reading, and looking at the systems offered by the various companies I put together my own setup.. I have less than $600 in setting up the car and building a super sweet filtration/dispensor getup.. Of course that doesn;t count my time in scrouging around for parts, and fabricaion...
I ran my old Rabbit about 125,000 miles on the stuff.. I replaced the headgasket after 113,000 miles of running on it.. Head gasket didn;t fail due to the wvo as far as I can tell.. It was a 1.5 with god know how many miles on it.. (Odometer quit right around 200K)
I wish I woudl have saved the pics, 3 of the cylinders looked typical except #1 which had some excess crap in it.. Turned out I had a bad injector on that cylinder... Can;t say that the injector failed because of the wvo either since it never really ran that smooth before I put the grease to it..
Still thinking about finding some sort of beater and trying some used motor oil in it.. I have a few 1.5's around that I wouldn;t feel too bad about destroying.. Just need a body...
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maxfax
what was it you spent 600 bucks on? and where else can i find a valve or is that a grease company only item that i would have to buy from them?
me it's just hard for me to scrounge all the parts! i prolly should read up more on the subject too!
Duane
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The $600 is a ball park figure for various parts... The Flat Plate Heat exchanger, various fittings, hose, line, steel to make the tank, the valves, switches, fuel gauge, oil temp gauge (that I will get re installed someday, for now I just go by the engine temp), and some other crap in there.. I'm including the parts I had to get for the filter housings and plumbing for my filtration system too....
I used valves from a carburated mid 80's F150.. They used them for the dual tanks.. These are electrically operated, and have 3 ports on them so I used 2... One for inlet, one for return..Fairly inexpensive, but not necessarily recomended since they are made from plastic... I've had no troubles with them as of yet.. I have seen metal valves somewhere that weren;t from the companies selling the kits... Both in electric and cable operation.. May have been on ebay or something... There aer some 6 port valves out there too that will handle both the inlet and return.. I preferred not to use them.. Less chance of cross contamination and no good way to purge the WVO at shutdown... With the 2 valves I can simply shut off the inlet valve and let the return keep flowing into the WVO tank.... I'm sure I get some diesel in the WVO tank, but I would rather have that than WVO in my diesel tank...
My tank is actually the bottom 8" of a 55 gallon drum.. I cut out a 3/16 circle and braized it on top to make a lid.. I have a hole cut in the center of the lid with a plate that bolts over it to access the internals.. I skeptically used Eastwoods gas tank sealer on the inside of it.. Wasn't sure how the stuff woudl handle the heat, so far so good.. For heating the tank I have about 10 feet of 1/2" copper tubing coiled around in there.. How hot the tank gets isn;t real critical since it only need to be hot enough for the IP to pump it.. Some only heat the tank, trouble with that is you have to wait till the whole tank full of oil is at 170 deg F before you can switch, and that can take forever. WIth the flat plate heat exchanger the oil is pretty much heated to temp on demand....
http://www.flatplate.com/index.htm
Ultimately I have about an 8 gallon tank that fits in the spare tire well on my Rabbit perfectly.. The only regret I have is that I have no baffle in the thing, and you can really feel it slosh on a hard turn..
I can get some pics tomorrow when it's day light.. They can probably explain things better than I can...
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Loads of info on veg oil running on www.vegetableoildiesel.co.uk. I go there for car advice too :)
There's a sticky on the SVO/WVO forum where one of the more clued up guys tells you why it's ok to run veg oil in an IDI engine. Basically, vapourisation and combustion is initiated in the swirl chamber, so that protects your cylinder walls...
I'll post some pics of the injectors when I pull them, if you want...
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i have been asked what nozzel size it good to run veg. oil thruogh an IDI?
in my nozzel group buy add!
Duane
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I am using everything stock! I don't think you need to change them...
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Stock nozzels here as well.. Elsbett that sells a kit to run older IDI diesles on SVO with one tank... I believe they use different nozzels for that..
IDI engine are alot more receptive to veg oil because of the precombustion chamber.... As long as it's warm as it's about impossible to get the chambers cleaned out if they get coked up..
I think I mentioned hearing mixed results with a diesel veg blend... Spoke with the one guy who has several diesle powered trucks and machines.. The IDI engines worked much better than thte DI engines..
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Anyone ever have an IP opened up that was run long term on WVO???
THere's always the argument that WVO is slightly acidic (which it is) and reaks havoc on IP internals..
No faiures for me so far, and for what I have saved on fuel over the years I think I could justify having the pump fixed if it does damage them..
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Used oil is acidic as far as I know, since the heat applied during cooking food creates free fatty acids (FFAs). I don't think virgin oil is acidic, is it?
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I had aquired some fuel grade soy oil , and it was pretty close neutral using a crude PH test...