Veg Oil Conversion Diary

[The Great Pretender]

Good work GP, I am watching this space with interest I'll be very interested in the tank & heat exchanger arrangement.
Just a thought, is it wise/necessary to have a return to the diesel tank? is that overcomplicating it & possibly contaminating the diesel with veg oil when the system purges?[/quote]

Watch this space.................. All will become clear grasshopper.

[missfixit70]

"Ok BDC n Kirsty, slow down a 555 chip and thermistors can be used to control the system but I want to prove it first. Lets go with the KISS system first, when we are walking maybe then we can try to run."

I can't argue with that logic GP wish I had the time & energy at the moment to be having a go myself, but I'm still not sure it's viable for me as I do a lot of short runs at the moment
I wait with baited breath (well, cidery breath anyway ) for the next instalment

[The Great Pretender]

For short runs, my diesel tank runs with 1/3 veg oil without any problems with startup (thats in it now) so your contamination question is answered.

[dandywarhol]

The pump has a return to the tank anyway Kirsty. I'm looking forward to the next stage too GP

Maybe the 555 chips could be cooked in any excess oil you have lying around

[mikeonb4c]

Out of interest, has anyone heard how Torchy is getting on with his system. He was talking about fitting something v like GPs and including a copper coil heat exchanger, which he showed us at Silverdale, but its gone very quiet since then

[missfixit70]

The pump has a return to the tank anyway Kirsty. I'm looking forward to the next stage too GP

I realise that Dandy, but what is now the diesel tank, I am assuming would become the veg oil tank & a smaller tank would be added for the diesel
My thinking being if one of the points of fitting the 2 tank system is to reduce strain on the fuel pump on start up by using pure diesel, if that becomes mixed with veg oil returning to it, is it defeating the point?

[mikeonb4c]

I'm not good at following the circuitry Kirsty (esp. when unwell as at present so pl. excuse me). But isn't he trying to ensure that diesel excess returns to the diesel tank and veg oil to the veg oil tank? So if he starts on diesel and returns to diesel before switch off that should be fine. But maybe I've missed something.

[The Great Pretender]

Hi peeps, ok a little clarification, Diesel tank will still be used for diesel. The existing fuel system is standard when running on diesel exept it passes through the heat exchanger (the thinking behind this is hopefully to improove fuel efficiency).
When running veg the return to the tank is closed and the fuel loops back into the supply to the heat exchanger to feed warmer veg.
Thats all for now folks, its back to fitting heat exchanger more pics this evening.

[Big Rich]

Hi Very nice assembly and pipe work ...can i share this photo with you (my spare bits) on parts ready avalable off web .... the problem with using home brew on fuel systems.... it will invalidate your insurance and you will prob req an sva type of inspection unless using type approved kit in fuel lines... ps i have a plastic 2 gall outboard fuel tank, This pump has leak off return back to seperate tanks as would be required, also my pump type is avalable direct from States, and is a diesel rated car pump, also it can look at both fuel guages when switched from tank to tank ... best regards Rich hope pics turn out ok
http://i223.photobucket.com/albums/dd28 ... CF2492.jpg
http://i223.photobucket.com/albums/dd28 ... CF2493.jpg

[The Great Pretender]

Thanks Rich, the pollack valve is only rated for a max of 60c I believe and there are Chinese copies that ar very sub standard. Thats why I decided to use four 2 way valves designed for petrol/lpg, they also have a manual switch incase of failure.

[flashgordon69]

Hi guys
The reason that they say not to use copper pipe for these sort of things is due to the fact that copper is soft and prolonged vibration will wear thru it!

[The Great Pretender]

Hi all, started to put it together today. The heat exchanger is from a Vailant combi boiler and more than capable. With the boiler supplying water at 80c it will heat over 2.1 gallons of cold water a minute by 35c. So with the Bongo passing what, a litre or so a minute through the exchanger im hoping for 70+c veg temp. Also the fittings on it are 1/2 and 3/4 inch BSP so no problems with connecting it up.



The next pic needs some explaining, when running on veg the fuel dosn't return to the tank but loops back into the supply to the heat exchanger hopefully increasing the temperature further. Im led to belive that it is possible to have a very small amount air included so this is my idea to remove it.



The fuel is fed through the 8mm pipe into 22mm fittings, as the liquid feeds into the larger pipework it slows down this increases the pressure and any air bubbles will rise. The brass unit on the top of the tee is an automatic air seperator that will bleed off any air. They are used in central heating systems and are rated at 10bar and 120c.

The feed to the FPHE was taken from the block and tee piece at the back of the drivers door.



Today was spent cobbling it together.



There are going to be two 25lt veg tanks in the back that will dissapear into a home made kitchen (hopefully).

Right im knackered now, time to wine down.

[The Great Pretender]

Hi guys
The reason that they say not to use copper pipe for these sort of things is due to the fact that copper is soft and prolonged vibration will wear thru it!

As you can see the copper pipes are connecting fixed points, vibration will ony wear through anything if it is rubbing on something else. Also vibration will work harden copper.

[Big Rich]

Hi The Great Pretender you have got to be a plumber with such neat pipe work! I live over in Chesterfield but do loads of work in Wigan...! on the lamberhead ind estate about once a month or so ....also good clear photos thanks Rich

[The Great Pretender]

Hi The Great Pretender you have got to be a plumber with such neat pipe work! I live over in Chesterfield but do loads of work in Wigan...! on the lamberhead ind estate about once a month or so ....also good clear photos thanks Rich

Thanks mate.
Gynaecologist actually Lots of tubes.

Was an heating engineer before I got discovered.