TDI on veggie oil

[Bush65]

I have taken an interest in this for some years now, but simply haven't bothered to date. The way fuel prices are heading here (Aus) it may be time to change.

I'm doing a trayback conversion at the moment and the old long range tank has gone. Instead of a new single tank behind the cab, I will look into having 2 tanks so that one can be used for svo, when I am close to sources of veggie (it would be used for diesel in remote areas).

In highland areas during winter, they used alpine blend diesel to overcome waxing. I believe this diesel has a quantity of heating oil or kerosene added to it. We find that performance on hills is improved with the alpine blend.

Some people claim to get performace and economy improvements by adding some unleaded petrol to each tank of diesel. They use a lubrication additive such as 2 stroke oil to make up for the reduction in lubricity from the petrol.

Others claim that they get even better results adding a small quantity of acetone to each tank of diesel. There is a fair bit of info on the internet about this here is one link.

If we accept these claims, then acetone (or petrol) with svo would be worth further investigation.

[freeagent]

i've heard about that one, acetone is supposed to help the fuel atomise....

http://www.vegetableoildiesel.co.uk/index.html

this firm, called goat industries sell an additive which you can put in your veggie oil to make it burn a bit more effectively, they seam to know their stuff, theres loads of info on their website.

i guess its just down to research, arming yourself with the facts before deciding what works for you... or what you are brave/mad/stupid/inovative enough to try....

[Turbocharger]

I've played with 5% petrol in the diesel before, saw absolutely no difference in power or consumption and for the 0.05% saving, don't bother now.

Simon - would you like to use a GPS widget to see if there's a difference in performance/power curves?

[white90]

[Turbocharger]

'Ere, 'ow does the second proportional manifold split the diesel and oil to return it to the tanks? Otherwise, over time you'll have a 5/95% mix in both tanks, surely?

[Michele]

X-Veg

Soon on these screens...?

B)

[GBMUD]

'Ere, 'ow does the second proportional manifold split the diesel and oil to return it to the tanks? Otherwise, over time you'll have a 5/95% mix in both tanks, surely?

If one were to arrange the fuel return to return to the mixed side of the valves (would have to be before the pump though) rather than to the tank then the problem would be eliminated. There may be potential problems with air getting in and not being released from the system though...

Chris

[GBMUD]

The result of my own study differs slightly from Simon's. Also a 200Tdi 90, although slightly older, 170,000miles. I started out with adding 6l of Tesco's cheapest to an almost full tank of mineral diesel - the tank holds 45-50l IIRC. The only measureable difference was that there was a different smell from the exhaust - I was not sure if there was a little more dark smoke with the engine working hard. Two days later (testerday) I started the Landrover as normal and there was no difference in starting performance and the engine ticked over well. Cold start test OK then - although ambient was about 15degrees. The engine drove fine from cold. I went out to try out a couple of greenlanes and to burn enough diesel mix to add another 6l of veggie oil. Added the oil and the engine continued to run and start well from hot. With the extra oil in the system I am now sure that there is more smoke visible when the engine is working hard - up hills at full throttle. It is not a lot but it is noticable. I have checked this morning and the engine still starts fine from cold. My estimate is that I am now running between 25% and 30% vegetable (rape) oil.

By the by, as I drove up the road from home yesterday I noticed that the local BP station had diesel up at 102.9, a couple of minutes later I was passing a field of rape just coming into flower. I thought about where my fuel, well, 25% of it, was coming from in future!

A few years ago I gave up smoking which had the net effect that I was hungry all the time and put on loads of weight. The Atkins diet fixed that - but then I stopped it and put the weight back on. I am now in a situation of needing to loose weight again but smelling the exhaust from my Landrover makes me feel ravenously hungry. What ever am I to do?

Chris

[TheRecklessEngineer]

I would conclude therefore that the stories of the oil not atomising and not burning when cold - is just plain untrue. The diesel and veg oil are misible i.e mix completly, do not separate out like oil & water. There is no way they wil magically separate in the injectors.

If the combustion was that poor when cold, I would expect a measurable reduction in mpg - emphasised by the short runs and the engine never reaching operating temperature.

Please dont say that. Its the veg component that will not atomise correctly - it congeals into blobs rather than a fine spray. Most likely, that because you have quite a high percentage of diesel in the tank, it burns first, then assisting the veggy.

I would very much expect you have lube oil contamination.

The reduction in combustion efficiency will not be measureable by mpg...I found I would loose about a litre of fuel into the lube oil every 1.5k miles or so - this equates to a reduction in mpg of 0.0006 (my blending experiment - 60% veg, 35% diesel, 5% petrol). This however, is more than enough to turn your lube oil into jelly (been there...done that....)

Also remember that the remainder of the veg is not simply "not combusting", but partially combusting - only a very small percentage will condense onto the cylinder walls. This will still result in a dramatic gas expansion and provide power.

[simonr]

'Ere, 'ow does the second proportional manifold split the diesel and oil to return it to the tanks? Otherwise, over time you'll have a 5/95% mix in both tanks, surely?

I figured that if you split the return in the same ratio, although you end up with a mixture in both tanks, the cross-over cancels out when you re-mix them.

You could feed all the return into the oil tank - then your proportion of diesel would increase as you went along - but you run the risk of over-flowing the oil tank if you are running less than 50/50.

Chris's Idea of running the fuel return to the lift pump inlet should work - maybe with a bleed valve there as well

Chris, could your extra smoke be because you have tweaked the fueling? If the oil does not burn as well, dumping extra in might make it burn even less well.

As a just in case, I have read that flooring it on hill climbs helps burn off a lot of the oil stuck to the bores. The fuel is cheap - so hay - I've been flooring it rather more than that!

Adding a bit of petrol seems reasonable. One year (doing the Lombard RAC as a radio vehicle) in Keilder, my diesel froze over night (it was getting down to -21 C). We got it going with a camping stove under the tank though.

A chap (army I think) suggested adding a splash of petrol to the tank - and it worked a treat. the engine had a bit more 'clatter' noise - but it didn't wax up nor freeze over night. We added 50% antifreeze to the screen-wash as well. The regular screenwash was freezing before it hit the screen and just bouncing off!

Si

[evil90]

I am currently running my 200tdi defender on somerfields special at 49pa litre50/50 with diesel and would say that the performance is ever so slightly better and it doesnt smoke as bad as before but the best thing is the smell is a lot more pleasent one of our club members runs his 200tdi on 100% veggie oil for a year now and has had no issues with it at all while another runs his td5 disco on it and only has problems when he runs too much oil in the winter as it doesnt like being started from cold

Frank

[Bush65]

...Its the veg component that will not atomise correctly - it congeals into blobs rather than a fine spray...

The link that I posted above regarding the benefits of adding small amounts of acetone, claims the acetone reduces the suface tension, enabling better atomisation.

He described tests, using a hot plate, for comparing the surface tension, which seem credible and can be confirmed with little trouble.

If this is correct, it may solve this problem from using svo or veggie plus diesel.

[western]

GBMUD

I am now in a situation of needing to loose weight again but smelling the exhaust from my Landrover makes me feel ravenously hungry. What ever am I to do?

could always eat the LR

[simonr]

The link that I posted above regarding the benefits of adding small amounts of acetone, claims the acetone reduces the suface tension, enabling better atomisation.

He described tests, using a hot plate, for comparing the surface tension, which seem credible and can be confirmed with little trouble.

If this is correct, it may solve this problem from using svo or veggie plus diesel.

It would certainly be worth a shot. Acetone is used as brush cleaner and nail varnish remover (in case Les wants to try it ) Homebase sell it - and it's pretty cheap.

Halfords had some 'Super power' (something like that anyway) fuel improver - which contains Acetone, Xylene and a couple of other things.

0.2% is about 100ml per tank in a 90

Si

[Tom P]

I personally think the best option is to uses converted veggie oil, saves all the time and hassle of fitting a twin tank system,

You could buy it or make it your self its not hard to make and its cheap as chips as you get the used oil for free or cheap and you can then sell the surpluses to local diesel owners to pay for materials,

I made my first test batch this weekend and surprisingly enough it worked.

Tom

[Richard Spandit]

I personally think the best option is to uses converted veggie oil, saves all the time and hassle of fitting a twin tank system,

You could buy it or make it your self its not hard to make and its cheap as chips as you get the used oil for free or cheap and you can then sell the surpluses to local diesel owners to pay for materials,

I made my first test batch this weekend and surprisingly enough it worked.

Tom

Are you talking about home filtered WVO or have you made biodiesel?

[jules]

I tried a 40% Tesco oil 60% diesel mix and found it pulled better but that could have been in my head.

Did smell of oil

Td5 no issues at all but my new job I have a fuel card for the disco so I run normal diesel (as in the words of my director why care with the company fuel card its cheaper than water)

[Cal]

3. Biodiesel is created from the transestrification of veg oil to create a suitable equivalent fuel to mineral diesel. But is not suitable for all vehicles. You also need suitable equipment/hazardous chemicals and somewhere to dispose of all the glycerine that you will produce. This is classified as toxic.

Does that mean true Biodiesel can be run without any modifications? I thought I had read somewhere you might still need a heat exchanger...?

It seems to me that the twin tank idea is becoming more and more common as you can run SVO, but don't you still have to pay full fuel duty on SVO? Also - where do you put the 2nd tank on a Disco if you need all your boot space?

Thanks guys - really interesting topic

[GBMUD]

Does that mean true Biodiesel can be run without any modifications? I thought I had read somewhere you might still need a heat exchanger...?

It seems to me that the twin tank idea is becoming more and more common as you can run SVO, but don't you still have to pay full fuel duty on SVO? Also - where do you put the 2nd tank on a Disco if you need all your boot space?

Thanks guys - really interesting topic

I bought proper, 100%, duty paid bio-diesel on my way to Billing this year for 95ppl. My 200Tdi 90 runs just fine on 100%, no problems. It should be a direct replacement for mineral diesel and have a BS number.

Chris

[Cal]

Thanks Chris - I'm keen to run on some form of veggie - ideally duty paid Biodiesel - just need a supplier close enough!

[GBMUD]

just need a supplier close enough!

Me too. I live near Bath and had to travel to Oxford to get any without going specially. It costs a fortune in Stroud, Glos. There is a place near Weston too, not open on weekends.

http://www.biodieselfillingstations.co.uk/

Looks like you will have to travel for it too.

Chris

[Cal]

Thanks for the link. I think I'm going to have to ask Mum and Dad if I can put a big tank (1000 litres?) in their garage and see if one of the companies will deliver.

I s'pose the other alternative is to try and make it yourself - saw these guys at the CLA Game Fair last weekend:

http://www.masterfarm.co.uk/

[geoffbeaumont]

I bought proper, 100%, duty paid bio-diesel on my way to Billing this year for 95ppl. My 200Tdi 90 runs just fine on 100%, no problems. It should be a direct replacement for mineral diesel and have a BS number.

Chris

As far as I could tell from my research recently, the only issue is that it can attach the rubber fuel lines on pre-95 vehicles (IIRC, they are natural rubber, more recent ones are synthetic). All that's required is to change the fuel lines for modern type if your vehicle is older than that.

There was also a warning that you should change your fuel filter after the first tank of biodiesel, as it's an agressive solvent and cleans all the crud out of your tank and fuel lines

[Andy]

i lob 60-70% SVO from sainsburys (nectar points) into my 200tdi, i think its got a bit more bottom end power but a fraction less revvy. im told veg burns slower so that would make sense to me, you get a longer burn the power pulse lasts longer at the bottom end but it cant burn quick enough to provide full power at higher revs.

ive been pouring it straight in for over a year now without a problem.

now & then i go back to plain diesel, just to check my feelings that it runs better in SVO and because i find if its stood for ages with fuel in then the SVO settles & the bottom of the tank turns a bit 'rich'.

im not planning on any of this fancy stuff with additives etc as im pretty sure it runs fine as im doing it.

[freeagent]

I run about 25% plain veggie oil from sainsburys in my 300Tdi disco, i've been doing it since i've had it (4 months) with no problems, i did it in my 300Tdi defender for almost 3 years before i sold it and the only problem i had was the injector leak-off hoses rotted, which cost about £2 to replace as i bought some heavy duty stuff from a supplier near me.

my emissions readings at MOT time got better every year even though i never tuned my engine, all i did was change the oil every 4K, and the fuel filter every 8K, and regularly used Wynns injector clener and Millers power plus fuel additive.

i don't do it when its realy cold, or just chuck the odd 3-litre on in, but when its realy hot i sneak it up to nearer 30-30% mix.

everyones experiences are different, but there are a lot of armchair experts out there, and a lot of people who just quote rubbish they've picked up from the web or various mechanics.... i'd say don't listen to anyone who hasn't actually done it..