bio diesel ?

[craigclagnut]

has anyone tried alternative fuels for their diesel?
is biodiesel from the forcourt the same as cooking oil from the super market?
there seems to be a lot of bollox written.
i've asked one mechanic and they said with my simple engine,
bio oil should be fine.
anyone???
t.

[madmog]

Biodiesel from the pump is not the same as vegetable oil. For a start the pump stuff will generally be a mix of biodiesel and fossil diesel; the percentagess being given by the name: B85, B99 etc.

Pure biodiesel is still not the same as vegetable oil however you can make biodiesel from vegetable oil. It's a fairly straightforward chemical process BUT dangerous if you don't know what you are doing.

Alternatively you can run diesel engines on vegetable oil - either new from the supermarket or used from the deep fat fryer. Then the main issue is filtering and reducing viscosity so that the diesel pump and injectors can cope. Veg-oil is more viscous than fossil or biodiesel. Biodiesel (vastly oversimplifying here) is basically vegetable oil that has its long chain molecules broken to shorter chain molecules to reduce viscosity. Filtering is done with er, filters. Thinning is done by mixing with fossil or biodiesel or pre-heating with electric elements in the tank or running the engine coolant through pipes in a second fuel tank. (or any combination of these). You start and get up to temperature on fossil diesel then switch to the then heated tank of veg-oil.

Additionally some injector pumps (Lucas CAV) will fail when running vegetable oil because veg-oil does not have the lubricity (?) required by the pump so it seizes. Bosch pumps are okay and Mercedes pumps which are lubricated by engine oil are best of all.

Oh and even if you are filtering waste veg oil from the kebab shop the VAT man will still want fuel duty. Way to encourage environmentally friendly fuels








Links
www.biodiesel.org/resources/biodiesel_basics/default.shtm
www.biofuels.fsnet.co.uk/basics.htm
www.biofuelssolutions.co.uk/about.asp
www.vegetableoildiesel.co.uk/
www.biodiesel.org/resources/biodiesel_basics/default.shtm

[Graham]

The manual on my TD5 disco specifically states not to run it on bio diesel ??

[GavinPearson]

Graham said:

The manual on my TD5 disco specifically states not to run it on bio diesel ??

Probably because they think there is a good chance that the fuel &/or emissions systems will fail if you use it.

Just bear in mind that during warranty when the parts go back for analysis after failure they can and will tell that bio fuel has been used. That means instant denial of a claim.

I wouldn't use it, regardless of the savings.

[Pigeon]

madmog said:

Biodiesel (vastly oversimplifying here) is basically vegetable oil that has its long chain molecules broken to shorter chain molecules to reduce viscosity. Filtering is done with er, filters.

[chemicalpedant]
The chains stay the same length, but they are broken off from the little bars to which they are attached in groups of three, so you get single chains instead of three in a clump.
[/chemicalpedant]

[motorwise]

GavinPearson said:

Graham said:

The manual on my TD5 disco specifically states not to run it on bio diesel ??

Probably because they think there is a good chance that the fuel &/or emissions systems will fail if you use it.

Just bear in mind that during warranty when the parts go back for analysis after failure they can and will tell that bio fuel has been used. That means instant denial of a claim.

I wouldn't use it, regardless of the savings.

I agree, it's especially cruel to single rail systems, use the real stuff all the time and you wont go wrong