Veg oil and EGTs

[molgrips]

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...

[arb]

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

[jtanguay]

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...

[the caveman]

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.

[zukgod1]

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.

[arb]

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 ?

[maxfax]

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

[molgrips]

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.

[the caveman]

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.

[jtanguay]

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.

[autoholic]

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.

[maxfax]

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...

[allsierra123]

What about waste motor oil anyone running it?

[maxfax]

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..

[allsierra123]

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.