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Fry oil to biodiesel...Why?

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meratz

New Member
If a diesel car or truck can run on well filtered fry oil, why go through the trouble of converting it to biodiesel? The chemicals used to convert the oil are nasty and it is something I do not want to deal with. From what I have read you can have a small tank of straight dieasel in your trunk for starting up and heating the fry oil. You then turn a valve which stops the flow of diesel and starts the flow of the fry oil. You then do the opposite when it is time to stop the engine to clear the engine of the oil so it doesn't solidify and clog your engine. This seems to make a lot of sense to me and keeps me free of chemicals more toxic than the original deisel I am trying to get away from or at least use less of. What am I missing?
 

Hero999

Banned
For the reasons you stated above, additives are required to stop it from clogging the engine when it cools.

It's also possible that other ingrediants are added to help lubricate and protect the engine.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
meratz said:
From what I have read you can have a small tank of straight dieasel in your trunk for starting up and heating the fry oil. You then turn a valve which stops the flow of diesel and starts the flow of the fry oil.
Have you ever heard of TVO? (Tractor Vapourising Oil), pre-diesel that's what tractors used to run on (a VERY cheap paraffin) - start up on petrol, then switch over when warm. We used to run an old Ford Popular pickup in the fields in the same way as kids, we fitted two motorbike tanks in the back, one petrol one TVO - mostly because we could pinch TVO from the farmers storage tank, and it cost hardly anything.
 

ericgibbs

Well-Known Member
Most Helpful Member
hi,
I saw a farming program recently, where the guy had converted his truck to run on cooking oil.
To get over the 'cold' start problem he bought an 'off the shelf' 12v heater coil, for the fuel line.
At ready to start up, he set the heater for about 20-30 secs, started OK every time.
 

Sceadwian

Banned
The emissions are going to be absolutly horendous.
 

mneary

New Member
In moderate climates, it's not hard to start a Diesel. When the temperature or atmospheric pressure drops it's another matter.

I had a VW Rabbit Diesel that never did start when I was at abut 12,000 ft and 15 degrees F. Fortunately I wanted to go downhill. It finally started at about 2,000 ft.

Preheating the oil sounds like a good idea if there's adequate battery capacity. Remember you may already be drawing 60A or so for glow plugs and 50-100A for the starter.

Emissions from biodiesel are ok if you really like fried food.
 

Sceadwian

Banned
Yeah, I bet atmospheric pressure can be hard on diesels. Throws the compression ratio right out the window.
 

Oznog

Active Member
I read up on this awhile ago, it's well described on the 'net.

IIRC not only is SVO (Straight Vegetable Oil as opposed to Biodiesel) difficult to start on, it can leave varnish deposits while cold. Also the SVO needs to be flushed on shutdown- I can't recall if that's because the engine varnishes as it cools down or because the fuel lines will contain SVO running right up to the engine so even if you try to switch the fuel system to normal diesel to get it started there's still SVO in the last part of the lines.

Preheating the lines ensures the SVO will flow in the cold, but it won't get the engine itself up to temp so varnish problems would still be there. Also if you have it gelled in the injector, heating up the line won't thin it there until the SVO starts flowing but it won't start flowing because the gel has clogged it. So ideally you'd need to heat the injector, line, even the bottom of the fuel tank to totally avoid the problem. In the real world, I imagine people still make it work with less than ideal heating systems though.

Also SVO can be of less than consistent quality, such as varying in PH. Some oils can be harmful to the engine. The biodiesel process can adjust for such things.

Biodiesel- or even SVO, IIRC- is actually pretty decent on emissions. OK won't compete with a Prius, but it's supposed to be pretty good.
 
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Hero999

Banned
Don't some vegitable oils absorb small amounts of water that could cause corrosion? Isn't that the reason why the engine needs to be flushed before it's shutdown?
 

kchriste

New Member
Forum Supporter
From what I have read you can have a small tank of straight dieasel in your trunk for starting up and heating the fry oil.
There was a guy here in town that used an unmodified Ford 150 pickup truck this way. It had dual tanks so all he had to do was put regular diesel oil in one tank and deep fryer oil in the other and remember to switch between them at the right moments.
 

Hero999

Banned
Is there a way to to this legally?

I don't fancy getting caught and having to pay a hefty fine.

I also have a feeling that it won't work on modern turbo diesel engines.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Hero999 said:
Is there a way to to this legally?

I don't fancy getting caught and having to pay a hefty fine.
Not in the UK, it's seriously illegal - the government don't like you defrauding them of excise duty - also bear in mind excise officers aren't hampered by the rules and regulations governing the police, no search warrants required, they can just kick your door in and enter!!.
 

Hero999

Banned
It wouldn't bother me if the government really taxed fuel just because it's bad for the enviroment, if that were the case then biodiesel would be tax-free but it isn't.
 
S

Souper man

Guest
"The emissions are going to be absolutly horendous"

Ive seen many programs that use fry oil, and they say it smells just like french fries!
 

Sceadwian

Banned
Too much of a good smell is a bad smell. Just try to sit next to someone that douses on gallons of after shave or perfume for more than a few minutes. Olfactory assault!
 
S

Souper man

Guest
but then again sceadwian, id rather have the whole world smell like french fries than diesel fuel!
lol
 

Sceadwian

Banned
Until you end up breathing so much fat in via your lungs you end up dieing from a heart attack or lung congestion 20 years earlier than normal because someone didn't think through an idea. These are the same kinds of sollutions to perceived problems that have gotten us where we are environmentally today as it is. People look for the best of the instantanious results, instead of the worst of the long term ones.
 
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Hero999

Banned
Sceadwian said:
Until you end up breathing so much fat in via your lungs you end up dieing from a heart attack or lung congestion 20 years earlier than normal because someone didn't think through an idea.
Lol :D

This waste of space is because the crappy forum software won't allow me to make sort replies.:rolleyes:
 
S

Souper man

Guest
Id rather die by french fries than choke on car emissions

French fries are the way to die! hooray
 
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