Alternative fuels > Waste Vegetable Oil
Cold starting on crappy wvo
sb118:
The fuel needs to be atomised. It's fine to have the compressed/heated air, but it needs a high surface area to act upon. Having a puddle of cold veg oil sitting on top of your piston isn't a suitable situation to start an engine.
I run my ford transit on SVO and it refuses point blank to start without me working the fuel filter and pump with the blow torch for a few minutes.
It's the heat that does the trick.
GuyFawkes:
--- Quote from: kyradawg on February 19, 2006, 10:52:28 PM ---SB118 and Guy,
Are you sure that it is the fuel being atomized that gets the mixture explosive?
--- End quote ---
totally
--- Quote ---Im of the school of thought that the rise in compression ratio and heat due to the displacement of compression space from the injected fuel is what gets the party started.
The reason I say this is because my ford f-250 diesel has no trouble starting on viscous fuel I just glow the plugs as normal and she fires right up!
Its not like on a gasoline engine where the incoming air charge needs to be humognious and volital in order to ignite.
Remember that in a diesel it is pressure and heat that causes combustion of the fuel not any sort of vaporized fuel or spark.
So I really think injector spray pattern plays little role.
Peace&Love :D, Darren
--- End quote ---
if you get a poor spray, eg when an injector needs serviceing or you run a different fuel, you get a "rattle" or "knock",
if you got no atomisation you got effectively no fuel exposed to oxygen (surface area of the drop) and you get no combustion
you can prove this to yourself if you like by taking the nozzle out of the injector, it'll still pump the metered amount in, and the motor won't run... do it too long and she'll hydraulic
kyradawg:
Guy,
Have you ever ran out of fuel in a diesel vehicle and just poured some oil down the intake? I have and it fires right up! No mist, atomisation just a puddle of fuel in the cylinder vroom! Oh yeah and a shit load of smoke.
If there was a midget in my engine compartment pouring oil in my intake I wouldnt even need a injection pump or injectors!
Your not "totally" sure you think your sure.
sb118,
The reason your having trouble cold starting doesnt have to do with spray pattern it has to do with the injection pumps ability to draw the fuel. The lift pump can only pull so hard if it can present fuel to the injection pump it will either be injected or something will break.
I understand that you guys have been told certian data and have chosen to believe it. I ask that you put your wankers back in your pants and relise its not a cock fight just a brother trying to stop the repression that has been incited by jelious folks that dont own diesels, big oil and just general haters.
Peace&Love :D, Darren
sb118:
This isn't a willy waving contest about who can preach about cold starting diesels, calm down.
I never knew that you could pull the injector on a hot engine and simply pour the fuel in. You might consider that the hot piston that the oil lands on will assist in vaporising the fuel.
I'm afraid this isn't information i've been fed, it's what i've experienced for myself, not trying to put a brother down, just trying to point out any possible flaws in the idea of reworking your head, hel if it works, you'll have solved a problem that a lot of people suffer from.
GuyFawkes:
--- Quote from: kyradawg on February 20, 2006, 03:00:30 AM ---Guy,
Have you ever ran out of fuel in a diesel vehicle and just poured some oil down the intake? I have and it fires right up! No mist, atomisation just a puddle of fuel in the cylinder vroom! Oh yeah and a shit load of smoke.
If there was a midget in my engine compartment pouring oil in my intake I wouldnt even need a injection pump or injectors!
Your not "totally" sure you think your sure.
--- End quote ---
I don't think I am sure, I am totally sure.
Your example is a quick way to kill a diesel, and note "ran out of fuel" happens to a hot engine, that will vapourise fuel by heat, BUT, unless you have a glass cylinder head you have no idea that it forms a puddle of fuel.
It has been. practically as long as diesels have been around, a rule of thumb that "if the bitch starts, there's not much wrong" and of course the inverse is true as well.
temperate climate winter, indirect injection diesel vehicle engine with electric heaters, remove the wires to the heaters and see what happens.... in my old 1900cc 4cyl renault diesel in the cold with no heaters it just will not start, with 2 heaters it just starts, with 3 its slightly lumpy but ok, with all 4 it not only starts, but runs properly from cold.
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I want to tell you people something here to put this in perspective, because I have been asked about veg oil before.
I have 2 cars, both non turbo no electronics under the bonnet renault 19 diesels, 1900 cc, indirect injection, heater plugs, 4 lungs.
One I paid 200 pounds for on ebay, the other 175, the 200 quid one I've had a couple of years, done mega miles, towed tons of shit with it, 100% reliable and returns 50+ mpg, the other one I bought a few weeks ago as a spare.
UK road diesel has a lower sulphur content and generally different formulation than american diesel.
Uk road diesel is 97 pence per litre, that's US$1.62 per litre
"red" of farm diesel is half of that, heavier heating oil a third
I won't run veg oil in my car, even though it is a cheap ass car.
I have yet to meet a veg oil enthusiast who has done serious mileage, eg 20,000 miles, eg 1000 engine hours, who has done an exhaust gas analysis and lube oil analysis and a strip and inspection.
I do know a couple of people who'se day job is analysing the combustion process inside IC engines and turbines etc etc
The Lister CS ran on a wider range of fuels than anything short of a turbine, but the one absolute sticking point for Mr Lister on what you ran in his engines was THE FUEL MUST BE A DISTILLATE.
There is a reason for that, purity.
eg it don't matter so much what you burn in the bitch, provided it, whatever "it" is, is pure.
veg oil isn't, waste veg oil especially isn't.
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speaking for myself, free per litre waste veg oil vs 40 pence per litre DISTILLATE diesel and even my old 200 quid car the DISTILLATE gets it every time.
it's not "dino" diesel, it's not "fossil" fuel, it is a DISTILLATE
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___IF___ for whatever reason I was forced into using veg oil, first off it would be mixed with pump diesel, but before it ever got that far I would get as close as I humanly could to making it as close as possible to a distillate.
why is veg oil diesel fuel cheap?
because no energy and no work has gone into distilling or cracking. DO that and it is the same price as pump diesel
is filtering enough?
no
I'd want to run it a few times through an alfa-laval (you ship boys will know what I mean) as a minimum.
course, that alfa-laval needs power to run.
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To all the bio diesel (and indeed listers camshafts were wrong) people I have only one comment.
There ain't no such thing as a free lunch.
yeah, you can run a listeroid on veg, but that free lunch thing means you get to do more work, like more strip inspect and cleans, more lube oil changes and purification, more accurate control of fuel / air / head temperatures, and ultimately more consumption of spare parts, more valve grinding, more sets of shells
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If ___I___ had to burn bio diesel and my source of power, and had no choice, I would burn it to make steam and run a steam engine, then I'd use some of that power to make a DISTILLATE for my more valuable motors, like the lister.
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