discomania
Well-Known Member
What sort of temperatures are you pre-heating to? Veg oil is still about double the recommended viscosity of diesel at 80°C!
But in theory your system would work yes.
I think we need to keep this post to lubricity - if we start on ring gumming, engine lube oil contamination, cetane rating, engine timing alterations to suit, lift pump modifications... we will never get away from our keyboards. This was ALL done to death about 10-15 years ago on this very forum!
@julianf - that was my theory in heating the SVO up as hot as I could get it (about 100C) to reduce the viscosity.
@discomania - what's your knowledge of *hot* SVO as opposed to ambient temperature gloop?
@discomania - what's your knowledge of *hot* SVO as opposed to ambient temperature gloop?
discomania
Well-Known Member
Knowledge in terms of... Viscosity? Lubricity capability?
Either really. I managed to get the oil up to about 100C before it went into the injector pump. The performance certainly wasn't what it was on proper diesel, but it worked reliably enough over a long period of time and many miles. I did put the occasional tank of diesel and injector cleaner through.
I'm just interested in the knowledge really. I have no intention of buying another diesel (I saw the writing on the wall for diesels some time ago and expect the authorities to all but ban them soon) and decided that a V8 on LPG was the way to go.
julianf
Well-Known Member
I would be interested to see some firm data on viscosity of diesel at, say, 25c Vs new rape seed, at 84c.
Whats diesel, about 35sec, right? So you're saying svo at 84c is about 70sec?
I don't know if you're right or not. I just know that I, personally, as in, in real actual life, know people who have been doing this stuff for year and years - I mean I go to a bio fuel meet once per year, and the chap with the PD golf has had it since I started going there, and that's got to be 8 years or so ago!
It's not like everyone else there changes their cars every 6months either.
Whats diesel, about 35sec, right? So you're saying svo at 84c is about 70sec?
I don't know if you're right or not. I just know that I, personally, as in, in real actual life, know people who have been doing this stuff for year and years - I mean I go to a bio fuel meet once per year, and the chap with the PD golf has had it since I started going there, and that's got to be 8 years or so ago!
It's not like everyone else there changes their cars every 6months either.
It is the SVO itself that is the contaminant and the gum it builds up inside the pump. I will say no more, don't want to get involved in a long pointless diatribe on the subject. If you think you know best carry on. But save up for a new injection pump.
Right, OK thankyou. I never said that I know best, I'm just interested to find out stuff that I didn't know
julianf
Well-Known Member
The irony is that a replacment IP for my motor would cost less than a tank of diesel!
Not that I've purchased either since buying the car about 6 years back!
(to clarify however, I personally run on methyesters, not triglycerides)
Turboman
Mab An Gov
Would that be modern DERV, DERV from 10 years ago when they first started adding biodiesel to the standard euromix, or DERV from the 1970s?
Because they are very different animals. Modern DERV is very dry, and doesn't lubricate very well, which is why a lot of people run additive in older vehicles. DERV from about 10 years ago was just a nightmare, because they hadn't learned to stabilise the formula with biodiesel in it yet.
DERV from the 70s and 80s was the real deal, smelly, slippery dino diesel, fuel pumps loved it!
discomania
Well-Known Member
Gas oil or 35sec oil is 2.00-5.00cSt - so is ULSD from the pump. Now I know that light fuel oil is 250sec and it's viscosity is about 8cSt - Corn oil at 80°C is 10.98cSt so that is greater than 250sec!
I don't have the figures in the "Little Black Book" for Rape Seed oil at 84°C however I do have almost all the other oils from 35° - 180°. So lets take Canola - Canola oil at 160°C is 4.29 cSt. Of the cheaper oils, it looks like Corn oil would be the most suitable oil as it has the lowest viscosity of them all at 95° of 8.56 - the best being Walnut oil at 8.21 - however, generally these are all quite high - so some mixing with DERV would be required to bring it down but it may end up more DERV than oil.
This is not really something that is ever encountered in a normal diesel engine but I wonder how hot a Bosch VE pump could handle pre-heated oil going into it. From about 145°C all oils are within the correct viscosity range but that is blinking hot - if that leaked out and sprayed over a red hot manifold you could be fairly sure of a good fire risk. At that all your fuel lines would need to be high temp stuff and you would need an fuel cooler on the return side as you couldn't end up with a tank of red hot oil sloshing about - the sender, among other things would melt. At this is sounds more like a mad experiment.
discomania
Well-Known Member
I suppose you also have the issue of the hot fuel being less dense, so for a given injection stroke less will actually go in compared to ambient temperature injection stroke.
Hot SVO is always going to be better, the I think even getting it up to 65°C would be a good start and then cut the fuel with something else, like DERV. But as said in my post above, there then becomes a point that the temperatures would just be insane. The heated oil would also help with stopping any gumming, although, when cooled it still can leave fatty deposits so it would make sense to finish on DERV - or to run a purge cycle - run a pump that pumps a couple of litres of DERV through the pump after shutdown.
Turboman
Mab An Gov
And probably not a very lucrative one either, given the time, money and effort involved to install the heater, and the relatively small price difference between diesel and veg oil.
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jamesmartin
Well-Known Member
canola is rape seed oil
Turboman
Mab An Gov
Yes, rape seed is known as Canola in North America, probably due to their being linguistically challenged.
Western Slope Rover
Well-Known Member
No, it's not that. We just believe that "rape seed" sounds far more negative than "canola".
Turboman
Mab An Gov
I will take your word for it, although in my experience you are unusually literate compared to many members of the US population.
In Britain, the crop is known as Oilseed Rape, I have never heard of anyone drawing unsavoury conclusions from that name, but maybe some do.
Nice to see you again, by the way!
Western Slope Rover
Well-Known Member
We Yanks are all about proper sensitivities.I will take your word for it, although in my experience you are unusually literate compared to many members of the US population.
In Britain, the crop is known as Oilseed Rape, I have never heard of anyone drawing unsavoury conclusions from that name, but maybe some do.
Nice to see you again, by the way!
discomania
Well-Known Member
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