Biodiesel in a 1.9JTDm GT,,, it works.
Good day gents.
I've been making my own Biodiesel for about 8 years and have been fuelling various Vauxhall Astras, a ford king cab, an old Nissan Patrol Gr with a lovely 4.2 and the last one was a Vectra 2.0DTI. The Vectra went pop four months ago (and I know why) and I managed to purchase a GT with the wife watching! Still not sure how I managed that!! 53 plate 70k on the clock.
This was the first high pressure diesel I'd tried and Biodiesellers usually shy away from Commonrails due to the high pressures resulting in high temperature fuel which is mostly recirculated to the tank. If you haven't made good Bio you can cause yourself a whole load of grief. Four months on and 80k on the clock it's still going fine. I've had no fuel related problems at all. I took it onto Bio over 3 to 4 tank fulls and it's been on 100% ever since. I know people will have a load of questions so I'll try and break it down into a few areas:
Biodiesl is made from vegetable oil during a chemical reaction with Methanol. A catalyst is required to get these two elements to react, you can use Sodium Hydroxide or Potassium Hydroxide. Most people make Biodisel using waste veg oil. One problem with this route is that every time the oil is used to cook with it becomes slightly more acidic. Fortunately the catalysts are very strong alkilis. A little bit of chemistry on the bench tells you how much extra catalyst to put in to not only complete the reaction but to bring the pH back to neutral. The catalyst must be mixed with the Methanol to form either Sodium Methoxide or Potassium Methoxide. This reaction like all chemical reactions creates heat and can bubble a bit giving off noxious fumes. I'll skip most of the numbers because I feel that would be too much info at this point. Once you have warmed and mixed your oil (to no more that 60C because Methanol boils off above 60C) you add the Methoxide. Carry on mixing for a while and after 30mins the reaction will be complete.
This however is just the start. As we are making bonofide Bio this is a chemical reaction and not a "I've made Biodiesel by thinning out veg oil with turps" situation. You will be left with Biodiesl that looks like veg oil but is now as runny as water and Glycerine (liquid soap) settling at the bottom. Job number one is to get the glycerine out. Most will drain off but some will stay in suspension. A filter media is probably best but a lot of people gently spray water on the top. The water droplets collect the soap particles (and Methanol) and you end up with clean, but now wet biodiesel and soapy water at the bottom. A filter media will remove the glycerine but most will not remove any excess Methanol. Whichever system you use you will now need to heat your Bio to drive off the remaining Methanol and/or dry it. Don't forget to filter the oil prior to putting it in the car now!
There you have it, I kept it as short as possible and it still went on and on. Making Biodiesl is far more involved than pouring veg oil in the tank and letting it mix with normal diesel or thinning veg oil with turps, kerosine etc. Lots of people have told me they run on Bio but on closer examination many or not.
Pitfalls with Biodiesl
A common problem during production is also a reason why Biodiesellers don't like common rails. At the water washing stage described above a lot of people make what the call in Bio circles, an emulsion. They go at the washing too vigorously and mash the oil (bio) with the soap and the water. Just think if you had oil on your hands, quick squirt of soap, splash of water and rub together. All threee ingredients combine,,, emulsion.
Now then, if you haven't made particularly good quality bio it may still have some glycerine in it and it may also be a bit damp. All that recirculating at high pressure is sounding a bit risky all of a sudden. What I have proved to myself over the past four months is that a common rail runs fine on bio so long as it is good quality bio.
Why is there exccess Methanol in the biodiesel and why do we need to get it out?
Making bio is a chemical reaction. X parts of veg oil to Y parts of methanol gives Z parts of bio and V parts of glycerine. The thing is that depending on which type of veg oil you are using the amount of methanol required changes slightly. You would be surprised at how many types of veg oil there are. A carpet bombing approach to methanol quantities is used which means a guaranteed reaction but excess methanol. Methanol attacks alluminium, enough said.
pH level? Too acidic or too alkili and parts of your fuel system will slowly start to disappear. When I first started out, and so it transpired, I was using the wrong amount of catalyst and was making slightly acidic fuel. I was also just letting my water washed fuel stand to let the water drop out. This was far from adequate. The acidic fuel stripping the cadnium plating from my fuel pump components and the the water rusted the pump, nice.
With any diesel engine you will get fuel blowing by the rings and therfore you will get fuel in your engine oil. Bio and engine will over time and with the bio in high enough levels form a grease type compound. Not ideal for engine lubrication. This is what did for my Vectra. I'd been running it on bio for just over 100k miles and had stuck to Vauxhalls 20k per oil chamge schedule. Yes 20k, I won't be doing that again. 1k from the next servie the big end went causing the pistons to hit the valves etc, etc.
Biodiesl dissolves natural rubber. Virtually all rubber components in cars are now Viton B rather than rubber. My "L" reg Patrol and "L" reg Astra were both fine so I think it has been standard across the board for quite some time. It really does destry rubber quickly so you'll know with hours not months. My GT is OK!!
Bio v Dino Diesel
Bio will make you r engine run noticably quieter.
Bio will clean out your fuel system of the microscopic crud that builds up while running on dino. This is why you take a higher mileage car onto bio slowly. Do it fast and you will block the fuel filter.
You should be able to make your bio for about 15p per litre but you may have to purchase the waste oil.
You are allowed to make 2500Lof bio for your own use each year before you need to pay road fuel duty.
Bio has roughly 5% less calorific value than dino. One early morning I managed to test my Vectra against an identical model. I did the blasting away from the lights thing at a motorway roundabout. Three sets of lights later and it was game on. We shot off down the slip road and by the time we got to 80mph his back bumper was level with my front bumper. At 15p per litre I can suffer that level of performance drop!!
So you see that even if you are attempting to make the real deal there are many things to consider and many things that can go wrong. I would never have started by putting my first batches into my Alfa. If you get it right though it is an endless source of intrigue from friends and neighbours. I now have a "Powered by Biodiesel" sticker on the back down by the exhaust. Oh and the exhaust fumes do smell of chips, indian, burgers, kfc.
Hope this has been helpful even if it went on and on and on.
I love my GT eventhough I have had to (most GT owners will nod knowingly all though this bit) replace a broken drivers door handle that came off in my hand, replace the squeaking front wishbones. I've put silscone oil on my door rubbers to stop the awful noise when you open the window. I've put uprated headlamp bulbs in due to the cronicly poor beams. I've got used to having 5 intermittent windscreen wiper settings with milliseconds of difference between eac setting. I've explained to the wife that you don't need a rear screen wiper,,,, you're not driving fast enough. I've explained to her that you don't need a handle to open the boot, actually that's a lie, why isn't there a handle or recess? I've got used to the indicators not turning off when I've left the roundabout. I've got used to the squeaking parcel shelf. I've fixed the high level brake light shining on the screen by taking it off, bending the anchor nut brackets and applying draught excluder. I've got used to my N/S headlight adjuster motor running when I put the lights on and most of the time it only goes off if I operate the wipers, explain that one?
Despite all of the above I love my GT. It is the first car in 14 years that I've owned which has a spirit, a carthat makes you want to, just go for a drive. It is the envy of many of my friends, not because it is the fastest car in the world or the newest, just because,,,, I'm not sure what it is but I know I never had strangers coming up to me and talking to me in the Spar shop about my Vectra.
I'll pop in now and agin and try and answer any questions that may be posted.