Veg oil conversion

Saltlick said:

I'm not sure where you're getting that info from Mark, but that's contrary to everything that I've heard/read since I started researching and using veg oil as fuel.

In my own experience this has been borne out by adding lube to the fuel like Millers Ecomax, ZX1 or Two stroke oil - without these the engine struggles to rev through the normal upper rpm range (eg 2200 - 3500), but with them it's fine.
As the fuel isn't really going to make much difference to mechanical drag/lubrication of pistons, it can only be the fuel delivery system that is suffering, as it runs at high pressure and is lubricated by the fuel only and must be that the IP and injectors are only able to work at limited speed due to the lack of lubricity in the fuel.

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It's well quoted on both the veg/bio forums I frequent.
I think the mechanical drag you are experiencing maybe more due to viscosity and slower burning of oil.

Yeah I'm not buying that, the oil is nice and hot and so thinned by the time it gets to the IP/injectors so I'm doubting it's slow burn, and what about slow or incomplete burn lower down the rev range? The power delivery is pretty much the same up to the rev limitation as when it's on diesel, and diesel itself is improved by adding Millers/ZX1/TSO but that can't be because the two stroke oil or other additive burns better than diesel.

If I thin the SVO with petrol/diesel I get the same effect but at a lower/higher ceiling until I add a lubricity additive. I've not yet experimented with adding 2-EHN to boost the cetane rating of the fuel yet, but I will do and test with SVO with and without 2 stroke, then the same with 2-EHN mixed in.

From your post I take it you run a heat exchanger, what other mods have you done ?

I must admit I'm so used to the "just bung it in brigade" or the "veg oil will kill your car " whereas you seem to have done your homework and found a system that works for you.

markSX said:

It's well quoted on both the veg/bio forums I frequent.
I think the mechanical drag you are experiencing maybe more due to viscosity and slower burning of oil.

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I dont know anything about veg oil, but he is right as regards the lubricity of fuel.
Older injection pumps were designed to be lubricated by the sulphur rich fuel, and now the fuel is less slippery, they can, and do, run into problems.
Anyone with DPA/DPS pumps will prolong their life by using lubricity additives.
Modern stuff should be designed to run on the modern fuel.

markSX said:

From your post I take it you run a heat exchanger, what other mods have you done ?

I must admit I'm so used to the "just bung it in brigade" or the "veg oil will kill your car " whereas you seem to have done your homework and found a system that works for you.

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I take your point
Yep, heat exchanger and a 12 volt glow plug heater bock as additional warming after the IP. I'm assembling some kit for water injection, purely for cleanliness and ensuring things stay running for a long time - my Disco IS going to become Trig's broom!
My set up is a twin tank with all oil feed going through the cabin, with the feeds going from tank, heat exchanger, to lift pump, to filter, to valve, to IP, to 12V Aux heater, to injectors.

At some point I'll do a wee write up or guide, as I've been asked a few times on the basic set up.

Sounds quite comprehensive, far more so than I intend to do.
I'm running a single tank, so far I've replaced all the fuel lines (bypassing the sedimenter), new Delfi lift pump and new tank sender unit, but this was trying to track down an air ingress issue, in the end it was the copper washer on the electrical switch on the fuel filter

I have a FPHE from a combi boiler to fit, I'm looking into a flame plug to aid starting and water injection is on the list.
Hoping to advance the timing by 3° at the weekend.

I assume your using WVO, what's your filtering setup ?

Nah, not too complicated - I just haven't explained it very well
Your plan/setup actually sounds very similar. I've not played with my IP timing for WVO but I've fitted a boost pin which has made a world of difference.

Filtering - I used to just use bag/sock filters from FilterBagMan, but it's very messy. I now use a 240v pump to filter through 10/5/1 micron filter cartridges which is so much more convenient. I need a second one to pump cleaned fuel direct to the car though, as I'm currently filtering as I need it, into a jerry can, then pouring into my boot tank which is a bit of a pain.

I've got 3x 205L steel drums, for a progressive settling/filtering arrangement, plus another cut in half with a sheet over the top as a first stage pre filter, all joined together with 22mm HDPE pipe and JG Speedfit connectors, and 22mm water/gas/oil valves and brass tank connectors.
It's not finished though, as every time I use it I think of another tweak/change I could or should make... and then never get around to doing it!

I said comprehensive, not complicated.

I advanced my timing today, it's made a big difference, before you could feel it holding back, but tonight it was almost back to diesel power and responceivnes.
Starts better and with a lot less smoke. well worth giving it a go, just be mindfull of diesel knock before changing over.

My plan is a two tank filtering setup, the first is for 400mu filter bags, then heat to dewater, then three stage filtering (10" housings and pump) into the storage ready for dispensing.