First things first, a quick thanks to brookster for sharing the info required for this conversion to happen, cheers mate I have been running both diesel and veg oil through one filter but this leads to excessive purge times as the filter needs to fill with diesel before the pump does....also during this period, diesel returns to the veg tank, not really an issue but in this application diesel is used for warming the engine at the start of a run and for flushing the veg oil out of the pump so its ready for the next cold start on diesel. The O.E. tank and fuel lines are used for the veg oil with an additional coolant heated heater fed by the expansion tank retrun. The second tank is a marine tank mounted in the boot used for diesel which is run as a closed loop system (diesel return is fed back into the diesel feed) so no veg oil can reach it. To reduce purge time i split the system in two with two filters (should have done it this way to start with) and place the 3 way solenoid feed valve after the filters and as close to the pump as possible, This means that only the pump has to be filled with diesel now. I've gone for two pre '87 golf diesel fuel filters to delete the sometimes troublesome o.e. return valve, the diesel filter in the o.e. location and the veg oil filter is behind the rad fan cowling as there really is nowhere else for it to go...as you can see, its a tight fit... So far so good, you can hear the engine change note within a minute after changing fuels and a complete change in exhaust smell with 2 minutes, at idle. The outlay for the conversion should be paid for once i have used 200 litres of veg oil, which, by my calculations, should be in around 2300miles Anyone thinking of doing this on a mk3 will need 5 metres of 8mm fuel hose, a marine tank, a heat exchanger, two filters, a 6mm pipe joiner (to delete the old return valve), a 8mm pipe joiner (to joint the o.e. fuel feed pipe to the veg oil system, a 8mm t piece (for creating the closed loop diesel system), two 3 way solenoid fuel valves, 14 8mm pipe clamps, 2 6mm clamps, 2 meters of 3-core cable with 8 female spade terminals and loads fo cable ties lol I bridged into the earth (brown wire) from the cigar lighter and the feed (back and yellow wire) to the heated rear screen switch...this was choosen as the heated rear screen will only be used when the engine is cold and if i think the system has blown a fuse (system defaults to diesel with no feeds to either solenoid valve) i can merley turn on the heated rear screen to see if the switch lights up to check. Switch over to veg oil takes places only when i have to turn the hot air setting on the heater controls away from 100% hot as this is a good indication that the heater is up to temp...purge is now done within 2 minutes of driving In the future i am going to change the fuel injector return lines and pump seals for viton items (can be done as and when they start to leak, whenever that may be). The o.e. fuel lines have been reported to be fine for veg oil so no need to touch these...I have viton seals and pipes coming from the states here's a video with the engine running on diesel [YOUTUBE]lEFby55LHeA&[/YOUTUBE] and now on veggie oil [YOUTUBE]TmZSYtrJJXE&[/YOUTUBE] Can you hear the difference? (video's taken when system was using one fuel filter)
Nice work The Purge is the only thing that's a pain and remembering to do it. Good Work Veg is the Future Fuel
Cheers mate Your thoughts on this idea please...I was thinking of adding another 3 way valve on the veggie return line...without any power it will return to the veg tank as is now but with it powered up it will return it to the feed just before the veg filter...the idea being that the heat stays where it is needed and isn't wasted by I it being returned back to the veg tank.
Nice work. More pics of the install would be great. Have you done any real driving in it yet, or are you still finishing the build?
I'll get more plcs when it isn't so bloody cold lol...I've done 460miles since the conversion and about 60 miles since updating to twin fillers
I Didn't have return on the Diesel, which worked well never tried it on the main tank feed but i do think on a long journey the hot fuel returning back to the tank assists with pre-heating the tank fuel. I used this plumbing system which shows the Diesel feed from the second tank routed back into the fuel feed line. also saves running a return back to the tank. Wiring diagram
Most of my journeys are to/from work which is 21 miles each way, 19 miles of which is dual carriageway...so you would recommend leaving it as is then?
it runs fine on veg, less clatter from the engine and less smoke...you just have to make sure the heater is up to temp before switching over. performance seems marginally more punchy, as for economy, its too early to tell but at 75p a litre, it would have to down to 30mpg to not make it financially viable
I'm that impressed with the system that I'm going to convert my Audi A3 tdi to twin tank wvo as well Veg oil...It's the future, I've smelt it...
twin tank loom schematic For those that are running twin tank set-ups, could you cast an eye on this circuit diagram I've knocked up on Paint for my install. Switches have LED indicators. Additional facet pump activated by WVO switch to supply IP, 3-way valves are Tecalemit items. Advice gratefully received cheers, Grant EDIT: I drew this up some time ago, and there was a reason that the return 3-way-valve only ran when purging Terrible ideal in retrospect, especially with the extra pump emptying the veg tank, so assume that it will run in tandem.
The return needs to be activated while on wvo, this will help to warm the wvo in the tank The valves myself and brookster used flow port 3+1 feed and 1+3 return without any power and from port 2+1 feed and 1+2 return with, so on diesel, both have no power and the diesel return is t pieced back into the diesel feed for a closed loop system...both valves are active on wvo so fed in and returned to o.e. fuel lines and tank...while on purge, the feed solenoid is inactive so diesel in but the return is active allowing the remaining wvo in the pump and lines to purge back to the o.e. tank. Purge time is crucial so as to not fill your wvo tank with diesel as I have been doing! With the valves as close to the pump as possible while using a two filter system, purge time is one minute at idle I can see the idea of a lift pump, but thin the wvo with 10% petrol (reduces viscosity by 50%) and add some cetane boost and it'll be fine without... Total duration on diesel on a run is three miles of warm up phase at the start and one minute at idle on purge at the end of the journey
After reducing the purge time, I've used 21litres of diesel to purge and start only whilst covering a distance of 640miles
This is looking more viable to me now, especialy with fuel rises again. If i run svo, do i need to get my pump rebuilt to deal with acidity etc?? Is svo not as acid as wvo???
I've not had mine rebuilt yet and its fine...I now have the special triangulated tool to replace the seals myself as and when they go I've been playing with the old girl again... A few modifcations were needed to be made to the centre bores of these MG ZR 16" wheels but they bolt straight on with no spacers or longer bolts required...the grease caps for the rear wheel bearings stick out too far to get the centre caps on but that is not an issue as this is no show car lol. The point of fitting these was to get the rolling radius up as much as possible and as cheaply as possible...the wheels and tyres were purchased for a whooping 44.50 (with one brand new 50 tyre fitted last week included!) from ebay and all modifications were carried out myself over a couple of hours after work...the shakedown run tonight was successful with no balance issues at all. As a bonus, the speedo is now bang on with gps whereas before 70mph on gps was 74'ish mph on the speedo
No mate, you need to mix veg oil with other bits and bobs (I've not looked into this as I chose a mk3 because it can run on 100% veg oil) to make biodiesel which means mixing yourself or buying premade meaning the tax man gets involved making it less financially viable but still doable
Nice car Lreg, i have ditched the idea of swapping shells so im going to purchase a 5 door gti and transfer all the exterior gti bits and interior along with the rear axle and front brakes etc to make a mk3 gttdi On the subject of mpg, i have decided against lpg due to a few underlining issues i have found from talking to my examiner. So im going for a methanol/water injection kit to add power and improve mpg. Plus it will work hand in hand with the evry mod for even more poke for overtaking etc. Im still up for fitting a twin tank kit though to run svo aswell.
Yours has been chipped so the evry mod isn't worth doing, surely? I run my car on veg with the weber alpha box turned on
Well this is what im unsure about. My idea was to have the meth injection working in normal mpg mod, spraying based on maf and map signal, with a secondary solonoid and nozzle activated when the evry mod is turned on. Iv sent m1ke a p.m to ask if he thinks the evry mod is safe to do. If he says like you pointed out, then iv lost 3 somthing on parts lol. The meth kit has a 2d smart controller so should see some appreciable gains in all areas.
