Tom: First, I will say that we have always stated that WVO (Waste Vegetable Oil) or new plant oil conversion systems are to be considered experimental and do not have millions of miles of testing that biodiesel has had, at least not yet.
The interest and the funding shifted to biodiesel early on, it seems, after the tests in the early 80's, which went more or less along the lines of: 1.Fill tank of then-current technology direct injection engine with sunflower or soy oil (most often, it seems) and see what happens. 2. Wait for a high incidence of failures. 3. Write the report: "does not work very well or for very long". I have no doubt that the researchers were sincere and reported accurately, but at least in the studies from that era that I have read there were some common themes which are not reflective of the way things are done now which are thought to improve the results. Notably: - there never seems to be mention of preheating the vegetable oil, to reduce viscosity and thus make it easier on the lift pump, injection pump, and also improve atomisaiton. That's the single biggest change, which seems to improve results. - the oils chosen were often less than ideal. According to the information I have, oils such as Canola/rapeseed/mustard, coconut, high oleic sunflower (recent) might have yielded better results. - the engines were often older type direct injection engines that did not have the sort of (with variations, of course) two-stage (pilot injection) high pressure, computer controlled systems we have today, nor the sort of combustion chamber designs that exist today. They were of course also not indirect injection engines (which many say will give better results on plant oils than direct injection). There have been quite successes in the use of indirect injection engines. - there was no mention made of using two tanks, for easier starting, operation of the engine on lighter fuel (diesel or biodiesel) until it was hot, and no purge cycle, again on the lighter and more combustible fuel, before shutdown. - also there is no mention of use of techniques such as blends of plant oils with solvents and cosolvents, in combination with preheating, as was done in some of the more recent, and very successful, trials of the ACREVO study, which is on our web site (blending 9% ethanol into rapeseed oil, preheating to 80C, and use in a small displacement direct injection engine yielded very good results) Regarding Shaine Tyson's comments, I am not sure how recent the study is that is mentioned, but if recent, then perhaps to put in proper context, I'd ask this: - were there a lot of premature failures documented, or is it just that these are mostly relatively recent conversions (most SVO conversions and kits having been done only since 2000 or so) and so the miles have not been accumulated yet, and there is insufficient data to come to any conclusion about the effectiveness of the use of, in particular, preheating and two-tank systems, for DI and IDI engines? If there was a high incidence of failures, were the causes examined? What were the failures modes? What would they be attributed to? If examined, were solutions sought? RE: "my list" - I don't *have* a list - that's the point - we need one at this point in time. And, BTW, dozens of examples would be a decent start, but not enough to really show anything. It'd be a start, though, if we did have a good list of at least that, a few dozen examples of SVO high-milers. That's what I was looking for help in compiling. It's mentioned now and then, and we see a few attempts, but I have not yet seen a serious effort at compiling a list of documented high-mileage successes, in the way that positive results were compiled for biodiesel, for example, while that was under development. It'd be nice to see it get a little more attention, especially in English, and especially in North America, I think. RE: "something funny" at 100,000-150,000 miles...well, no, I don't think there is any magic number: we have all seen the reports and horror stories about engines being ruined by use of plant oils in short order - so many hours, so many miles - again, mostly of the sort and from the era and conditions mentioned above ...but then we seem now to also be hearing more and more of better long term results than predicted - so far, too much anecdotally. That needs to be examined in more detail. If there are getting to be a good number of successes in teh longer term, how are they being accomplished? What are the best practices? Of course, I have my own ideas on that, as do many others, and some have been incorporated into kits, some would be related to engine type, conditions of use, type of fuel oil used, type of lubricating oil used, and so on. Those need to be examined again - if something seems to be working (i.e. there is progress being made), then find out what it is. If there are still, after doing those things, problem areas, identify them, see what can be done about them, or might be, or identify the knowledge gaps. You know, SVO has been written into the European Union rules as an acceptable alternative fuel, alongside many others, including biodiesel. An original Elsbett engine in a Mercedes has recently, it is reported, gone over one million (!!) kilometers on vegetable oil. That's was a direct injection engine, and it is also said that much of the technology used in that engine's injector and combustion chamber design found its way into the TDI many years later! RE: the rumours of "horrors of TDI" conversion....I am not sure what you refer to here, I have not heard much of this. I do know that the TDI runs cool, does not generate a lot of waste heat, and so if run under light loads on poorly heated oil, that could be a problem. I have been told they have a tendency to "coke up", even on diesel fuel - at least that's what my VW-dealer-mechanic friend told me, and I suspect that would be worse if they are run under light loads or in the city a lot. So, the preheating, electric preheating, and two tank (on diesel or biodiesel until the engine gets hotter), would help in that, I would think. Regards, Edward Beggs On Tuesday, May 11, 2004, at 04:23 PM, [EMAIL PROTECTED] wrote: > Ed- > > I think I should step gingerly here, I know you promote WVO conversion > systems. However, I refer to Shaine Tyson, late of the National > Renewable Energy > Laboratory who gave a talk in Connecticut last year, stating that in > all of the > national research, only one truck was found that had lasted 150,000 > miles on > SVO. How does this square with your list? Are you starting out with > dozens of > examples, or is it a short list? Something funny happen over 100,000 > and under > 150,000, or is this technology particularly hard on direct injection > engines? > We want to know the real value of this technology. Are the rumors > about the > horrors of TDI conversions true? Why, what goes wrong? > > Tom Leue > > In a message dated 5/11/04 2:10:49 AM, [EMAIL PROTECTED] writes: > > >> Hi all, >> >> I often get asked how many engines, specifically modern direct >> injection engines, I know of, that have gone more than the magic >> number >> (for some reason) of 100,000 miles (yes, miles, not kilometers, >> please...so, let's say over 160,000 km) >> >> I know I could spend hours scouring the databases, such as they exist, >> translating from German sites, etc. etc...but if anyone needs a good >> research project for academic work, this is one!! >> >> Or, if you just want to send me notice of examples of such that you >> are >> aware of, please do! >> >> Please exclude old Mercedes.....I know there are lots of those that >> have gone that far...I am looking for TDI's, modern trucks, equivalent >> hours on gensets or tractors (let's see...1600 hours at 100 >> km/h....ok, >> let's say over 1600 hours),Ê etc. >> >> I'll compile these as they come in, unless someone out there can set >> up >> a self-admin database for us, which would be a heck of a lot easier, >> and more accessible for all.... >> >> The SVO 100,000 Mile Club Database.....anyone up for doing that? >> >> We can host it on our server space if need be, I think. >> >> Spread the word? Help get it going? >> >> Thank you! >> >> Edward Beggs >> > > > > > > > ----------------------------- > Homestead Inc. > www.yellowbiodiesel.com > > > > [Non-text portions of this message have been removed] > > > > > ------------------------ Yahoo! Groups Sponsor > ---------------------~--> > Yahoo! Domains - Claim yours for only $14.70 > http://us.click.yahoo.com/Z1wmxD/DREIAA/yQLSAA/FGYolB/TM > --------------------------------------------------------------------- > ~-> > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > > Biofuels list archives: > http://infoarchive.net/sgroup/biofuel/ > > Please do NOT send Unsubscribe messages to the list address. > To unsubscribe, send an email to: > [EMAIL PROTECTED] > Yahoo! Groups Links > > > > > ------------------------ Yahoo! Groups Sponsor ---------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. 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