Thread: 300tdi on bio?

put a time clock solinoid on the second tank so it is not available during lunch hours
:-)

So the only concern really is the quality of the Bio and nothing else?

Originally Posted by rick130

Proper bio diesel as opposed to WVO is an esterfied fat or oil, and in theory should have a far better lubricity than conventional ULSD diesel however...

esters, by their nature are conventional elastomer seal swellers and softeners.
esters have a natural degree of detergency (as many have found out )
some esters are polar. (meaning they have an affinity for other polar items like metals)
some esters have an affinity for water.
some esters react with water and become corrosive.
Last time I asked a chemist I was told there are over 200 different types of di-abasic and poly-ol esters that are used as hydraulic fluids and lubricants.

The seal swelling problem is overcome by using the correct seal material.
AFAIK Viton, a flurocarbon elastomer is the seal of choice.

IIRC older pumps used nitrile seals. Nitrile loses it's elasticity with age, soak it with a seal sweller, particularly if there's a little bit of garbage caught behind it and it will probably seal better for a while, then the crap gets washed away, and eventually the seal either becomes too soft to support the pressure behind it and leaks or it tears.
Pump overhaul time.

The other thing to consider with bio diesel is;

What standards does the bio conform to ?
Who has tested it ?

Conventional diesel from the majors has to conform to the current Oz standard for sulphur, cetane, lubricity, etc.

Some more points to consider.
There should be less soot with bio diesel so less strain on the lubricating oil from that aspect.
If using a mechanical rotary injector pump it should last a lot longer with bio if it's good bio diesel
I'm suspect of bio-diesel from a fuel dilution point as per the link Simon posted above, but better oils will alleviate this.
Shorter oil change intervals of 5-7,500km should help in the short term, but I have no testing to reference to see if this holds true.

I have just been working in a fuel injection shop rebuilding pumps and injectors the boss said to stay away from bio fuels, they wear pumps and injectors out quicker as they have less lubrication properties than standard diesel and the pumps on bio are so dirty on the inside. and i think there was an issue with catalitic converters and particulate traps becoming damaged, not sure if the euro bio is better than ours, their standard fuel is better than ours.

Originally Posted by clean32

So the only concern really is the quality of the Bio and nothing else?

primarily yes, but its not just one quality control factor that you have to worry about.

theres 3 different chemical techniques Im aware of for making "biodiesel" and Im not entirely convinced they all like each other. my point being that if you got fuel from blend method A and mixed it with method C it might become acidic and eat the metal out of your fuel pump but if you mixed B with A it might turn into clag glue and block your filter. Thats just a gut feeling tho, if your making your own you dont need to worry about it unless you decide you want to go with a different method.

the second thing is the condition of your engine and fuel system. In the same way that diesel engine oil is different to petrol engine oil if you run a petrol engine on diesel oil from the get go its all good but if you put a diesel engine oil in a petrol (over a prolonged time) after its been well and truely run in on petrol engine oil then bad things can happen. Dino diesel vs Bio diesel has a similar effect.

the last thing you need to worry about is the breakdown point of bio. the higher your injection pressure the more of a problem it becomes, this is the main reason I sit with the no bio in td5's crowd the TDI runs close to the point that I consider that BIO looses lubricity theres a comfortable margin on a set of injectors running at the advertised OEM pressures but what about if the pumps been tweaked or you get a set that are on the tight side?

other than that if bios going to do bad juju to a tdi it was going to happen anyway but it will potentially happen earlier.

Originally Posted by clean32

So the only concern really is the quality of the Bio and nothing else?

The potential fuel dilution issue I posted about after that post is a biggie too IMO.
Bio is a lot less volatile than dino diesel so it will stay in the crankcase and dilute the engine oil. Not good.

Fuel dilution is always a problem with diesels. But biodiesel is less volatile. Hence, while the
mineral component may evaporate, the “bio” part does not. This of course lowers the viscosity
of the oil. However, to counter that, the “bios” are not as oxidatively stable so the oil thickens
again – but with the usual oxidation by-products occurring (but worse) such as sludge and
increased piston deposits. So the combination of the two factors can impact engine wear.
Poor quality biodiesel may also lead to ash build up in diesel particulate filters and work is
continuing on that factor. In Europe and the USA, there are tight specifications for the “bio”
component to ensure that overall fuel quality is not compromised. So simply blending your old
cooking oil with your fuel is not a wise option.
While many OEMs accept B5 diesel, recent work has found that even that 5% dilution can have
a major impact on oil life and that lubricant selection will be critical.

from here http://www.penriteoil.com.au/files/2...%20BIOFUEL.pdf

5% fuel dilution is catastrophe time for engine wear IMO, I aim for under 0.5% dilution with conventional diesel and premium lubes, although most Australian labs can't seem to be able to measure under 1%.

rick, if you like I'll get you the contact details of the lab that does the busmaster sample analysis. Pm me if your interested.

Dave, I totaly agree. you would probably be safe running bio on an old toyoata 2H or nissan TD42 but as you said with the higher injection pressures of the rover motors its not worth the risk.

Hi Folks,

Crap, crap and more crap! (excuse the french!)

But...I read this stuff all the time about the good, bad and ugly of biodiesel (aka. long chain alkyl ((in this case methyl esters)) made by esterification of vegetable oil and/or animal fats)

I normaly hold my council and look on with quite ammusement as the subject is debated to death (usually by oil company proponents or at the very least by some serious influence brought to bear by them or their representatives).

A recent thread on this forum about catalytic converters and bio diesel provided the catalyst for this response (pardon the pun!)... like I said.... I normally sit back and just observe.

Whenever I hear of a new argument as to why biodiesel should be avoided at all costs, I immediately phone my good mate who is a currently practicing industrial chemist. After a five minute in depth explanation it became immediately obvious that the mechanic who reckons that (good) bio will damage a catalytic converter should perhaps stick more to mechanicing than philosophy. The same goes for high pressure lubricity (more on that later)

Whenever I hear about all the problems associated with high acidity, high alkalinity, high water levels, excess this and excess that, it is blatantly obvious that we are not talking about biodiesel as per the description in parragraph 2 above.

Properly produced biodiesel has a PH level that is near neutral, has little or no soaps (mainly due to transesterification or presence of water in the oil stock) and has very little, if any residual glycerin and does not contain any residual methanol. Incidentally, methanol is a very common additive used in scandinavian countries to winterize fossil fuel diesel at rates up to 20%/vol. I have that first hand from a visiting Rotarian bus operator from Stockholm.

So.... if we are going to keep the debate in perspective, we really need to base it on biodiesel that is properly made (in a backyard perspective)

And it's not that hard to do. If you are using waste vegetable oil then the correct titration procedure is critical, as well as the correct volume of methanol, the temperature and length of the reaction time and more importanly, the filtering/cleaning of the final product.

I have been producing biodiesel for about six years and have run all my vehicles exclusively on B100 in all of that time. I have run it in a number of different engines including the 300Tdi at B100 for a number of years and have had no problems whatsoever.

Five years ago I purchased a Mazda Capella Diesel (Japanese imported 626). When first purchased at 145000, injector wear was causing noticable black smoke. The engine has now done 330000, same injectors, same pump and the smoke is now less than when first purchased. I also completely rebuilt another RF7 Mazda engine in one of my other Capella's three years ago. That had done over 300k and was dead tired. The very same injectors and pump have since done over 70k on B100. Compression is so good, that it will start on just a twitch of the ignition key and ther aint any smoke!

My 97 Tdi300 has had nothing else other than B100 for the past 40000km and I have had no trouble other than the rubber hoses on the injector bypass lines. I changed them to viton and they have been fine ever since.

I have never heard of or directly observed the death of an injector pump due to seals or otherwise caused by (good) biodiesel. Neither has my local diesel injector technician. Common failure that is commonly blamed by biodiesel is the front shaft seal wear caused by excessive dust inside the timing cover. That can and will happen with fossil diesel as well.

So... in the interests of good healthy discussion and in defence of the poor old biodiesel, let us please keep the comments and observations directly relative to properly made (back yard or otherwise) biodiesel.

In relation to high pressure lubricity, I have discussed this with more than one industrial chemist. They all agree that properly made alkyl methyl esters will not suffer from reduced lubricity under high and even extreme pressures. I have been told by them that there is no reason why good B100 should not provide adequate lubricity even in common rail engines. As a matter of fact they all claim that biodiesel is a better fuel for common rail than fossil fuel.

In any event, there are a number of forum members and also biodiesel forum members that have successfully used B100 in the Td5 engine for extended periods of time with no ill effects. A good number of European manufacturers now also alow B20 to be used in common rail. If it were so bad, would that be allowed????

With all due respect to forum participants, it seems that the perceived potential engine damage from using good biodiesel is directly proportiional to the cost of replacing the injectors and pumps. With what I know from direct experience, I would have no hesitation whatsoever in pouring good B100 directly into the tank of a Td5.

As a matter of fact.... at least I know where it came from.... how it was stored and that it is filtered down to 5 microns. Beyond the refinery gate, the rest of us would only be guessing!!

Regards
Maarten