Myth Busters and UVO vs Diesel

[bowtieguy]

i didn't get the gist of it, but the guys compared the efficiency of UVO to diesel.

the test car was a full size mercedes benz diesel. same amount of fuel on the same track yielded ~30 mpg UVO and ~33 mpg diesel. ~10% decrease for substantially less money sounds great.

here's the thing that caught my attention: they claimed the UVO was UUVO(unmodified used veggie oil). so is it possible to simply poor and drive? surely it must have been filtered.

anyone else see this episode?

[theholycow]

I did not see it, but by your description I suspect that they were trying to be extra clear that they weren't talking about biodiesel. It's distressingly common for people to think SVO, WVO, and biodiesel are the same thing. I doubt that they ran it unfiltered.

I'd like to build a vehicle that processes it entirely onboard, so I just pour any waste oil in and it gets completely filtered, the water settled out of it, etc. It seems that most people collect used oil, filter and settle it at home, and then put it in their vehicle.

[bowtieguy]

i got a buddy that is using it(used or waste veggie oil). he filters it twice and adds a "secret blend" proprietary chemical.

he is trying to find the secret and make his own. it seems the myth busters were able to skip the chemical additive, claiming no ill affects. my question is, what about long term affects?

[Wazabi Owner]

I'd like to do an onboard filtering system too. Right now I do the slow triple filter. I first run it through a 50 micron, then a 15 and finally a 1 micron. My oil is also pretty clean to start with as well - a good buddy gives it to me so he takes care to keep trash out of it.

[theholycow]

Originally Posted by bowtieguy

i got a buddy that is using it(used or waste veggie oil). he filters it twice and adds a "secret blend" proprietary chemical.

What system is he using and what is the name/source of the "secret blend"? I have read a lot about WVO/SVO systems, but I have zero actual experience; still I expect I would have heard of it at least once.

[RoadWarrior]

Secret blend is probably varsol, kerosene, turpentine or gas

[Jay2TheRescue]

I saw the episode of Mythbusters you are speaking of. I believe all they did was filter some waste peanut oil. Its been a while since I've seen that episode.

[bowtieguy]

Originally Posted by theholycow

What system is he using and what is the name/source of the "secret blend"? I have read a lot about WVO/SVO systems, but I have zero actual experience; still I expect I would have heard of it at least once.

it's called "diesel secret" and it is an anti-gel agent. www.dieselsecret.com

he mixes:
50 gal VWO (clear, non-hydrogenated is preferred)
5 gal kerosene
2.5 gal gas
12 oz high octane cetane
8 oz diesel secret

he pays .15 to .25/gal for the VWO. also, he is working on water injection as well.

he told me you could call him for specifics. just PM me if that's what you'd like.

[theholycow]

I don't need to call, that's specific enough. I'm not doing any WVO projects right now, I'm just interested.

Putting all that stuff together sounds like as much work as making biodiesel out of the WVO.

[Headshot Zod]

[quote=bowtieguy;107629]

so is it possible to simply poor and drive? surely it must have been filtered.

[quote]

Sure you can filter, pour and drive, however since you aren't getting the veggie oil up to operating temperature, it won't atomize as well as diesel. So, you may read about older diesels (which burn wvo better) like the mercedes doing "one-tank" systems, or engines like the Elsbett (which probably work). If I am not mistaken, the problem is that when the veggie oil doesn't atomize correctly it drips on the injector. Then it starts to cook on the injectors leading to bad spray patterns and eventually a toasted injector.

I think greasel had a "filter as you go" thing. The only problem is that you want to let the veggie oil settle for a couple of weeks. This can't happen if you are driving the vehicle. Letting the oil settle for a few weeks will save you on filters.

Also once the temperature starts dropping below 50, straight veggie oil will turn into a solid. This depends on how high much hydrogenation is in the oil. But ultimately it looks like butter by the time you hit the high 30's. This will not make your injection pump particularly happy.

just a thought......

[mpcondo]

WVO has to be filtered down to 5 microns otherwise it will damage your engine. however, using VO of any kind can damage your engine if its viscocity is not modified in some way. Many people use a VO and petro-diesel blend, some use a VO and kerosene blend, some make Biodiesel, and others use a heated fuel tank in order to lower the viscocity and reduce the amount of deposits left in the engine.

[Lug_Nut]

Low pressure InDirect Injection injection systems are far more forgiving of the viscosity variances in veg oil. I'm not surprised the Merc started and ran. The lowered fuel economy noticed is in part due to the relatively inert glycerin portion of the veg oil tri-gliceride molecules.
Higher pressure direct injection fuel injection systems (VW's TDI) are less forgiving of variances in viscosity from the petrodiesel on which they were designed to run. The interim unit injector technology (VW called theirs Pumpe-Duse), was far less tolerant. The current technology of common rail injection systems from Mercedes and 2009 VW diesels and others are even less tolerant yet. Operating pressures had been climbing dramatically, at the same time clearances and machining tolerances have been reduced, all in the name of lower emissions and higher power.
The practice of heating the oil to reduce its viscosity works towards reducing one issue, but increases another. The injector pumps are cooled by the fuel coursing through them. Operating the pumps at sustained temperatures of 180F due to heated fuel is not within their original design criteria. Seals degrade more quickly, the chemical reactions (rusting, deposit accretion, polymerization) happen more readily and more quickly at elevated temperatures.

What no-one has mentioned yet, and my biggest concern with veg oil as fuel in compression ignition engines, is the water content and the dissolved mineral content, especially with re-claimed cooking oils. The ocean can be filtered to sub-micron levels, but it isn't acceptable to run it in an engine.
Conversion of the oil into biodiesel by means of chemically separating the glycerin backbone (and any salts) from the esters and allowing sufficient time for stratification and settling makes the ester fuel portion C19H40 nearly chemically identical to petroleum diesel C18H38. This 19 carbon chain length biodiesel molecule has far less viscosity difference from the 18 carbon diesel fuel molecule and significantly reduces the risk of fuel system damage.
Biodiesel is easy to make from veg oil. Unfortunately it is also as easy to make a bad batch.

[Headshot Zod]

Infopop has a huge and I mean huge thread on dewatering wvo. I think sunwizard was doing it. I believe you can mist/wash solubles out of the wvo. I haven't tried since the beast is offline.

[bowtieguy]

Originally Posted by theholycow

Putting all that stuff together sounds like as much work as making biodiesel out of the WVO.

agreed!, for the average commuter, this IS a lot of work. my buddy has a small fleet of HD trucks, so it pays WELL for him!

[Dust]

ANyone using diesel secret should do a search on TDIclub or other diesel websites. Not too many good things said. I remember the water injection thread on infopop. Still don't know what ever came of it, as far as reducing problems when using WVO.

[gaswaterman]

Discover The Biggest Secret They're Trying To Keep From You:
"How To Convert Your Car To Burn WATER & Gas,
Cut Your Costs by 60%, Enhance Engine Power & Safety
and Clean up The Environment...

http://shmyl.com/qtjqson

[theholycow]

FOAD.