Bongo Fury

I have been running my Bongo on a rapeseed/diesel fuel mix and its running lovely.
I have just been told by a friend who works for a diesel engine company that it is advisable to change the engine oil twice as often as normal due to veg oil affecting its performance after a much shorter time
Anyone else heard of this?

There is a rumour that veg oil can clog the piston rings and allow gases to pollute the engine oil. Some say it only applies to direct injection diesels (which the Bongo isn't) and my oil seems fine after using up to 50/50 in the warmer weather.

My oil was changed around 2000 miles ago (semi synth 10/40) and is still fine...Its not p155y thin yet...

I'm running 15-20% veggie at the mo.....

Hi
Yes he did say it was something to do with blowback past the rings

Cold starting and until the veg oil is up to temp (viscosity reduced enough) and atomizes correctly when injected is where the problem lies. Blobs of veg on the cylinder walls can then get into and past the piston rings of a cold engine. Eventually the rings will gum up, the first sign of a problem can be engine oil level rising or not using any oil. Veg oil in normal engine oil will polermerize the oil (turn engine oil to jelly) then..................BANG............

So if you think that just because it coughs a little on startup then runs ok everything is fine, remember a few thousand miles for a prooven diesel engine is peanuts.

The change oil early is the belt. Twin tank and dont idle on veg oil is the braces.
Hope this helps.

It does indeed T.G.P.... I'll be getting my oil & filter changed this week just as a precaution...

Thanks for that

bigdaddycain wrote:It does indeed T.G.P.... I'll be getting my oil & filter changed this week just as a precaution...

Thanks for that

Do it tomorrow before you go to Aldi.........

Or straight after.....

bigdaddycain wrote:Or straight after.....

I have a cunning plan

Ooer....

T.G.P. - you see mto know what you are talking about here. I have 10l of Pura waiting to go in the Bongo when I find the courage. Could I sound you out on this idea:

At present the Bongo is only doing short/cold runs. I'm not doing many miles in it so no more than about 1 tank every 4 weeks. Not a huge monthly saving, and poor conditions for veg oil mix.

However, when I take off on longer runs in warmer weather, I could literally start the engine and warm it before setting off, then tip veg oil in before driving off. Top up with diesel fuel (minus space for veg oil) near my destination. When about to make return trip, warm engine and pop veg oil in again.

Using this technique, I should be able to put a high percentage of vegoil in (50%) whilst avoiding the potential issues with cold running and veg oil, and I would enjoy savings on long runs.

Is this a sound idea in your view?

You can get a veg oil based lubricating oil called plantomot, this will not degrade like normal oil (polymerise), and is about the same cost. (well as a high grade oil anyway (£30 /5L).

Diesel veg in wolverhampton sell it. http://www.dieselveg.com/plantomot_engine_oil.htm

Check the oil regularly it can go suddenly thick and that is bad news....

Ours runs on 100% in the summer, and 85% in the winter, twin tank diesel veg conversion....
I am currently experimenting with food flavouring to see if I can change the exhaust smell!!!!

Yes, I know I am a little loopy....

Mike, while that might work, it seems a bit of a hassle.

I have the purge control set to about 75secs on our conversion to flush out diesel before stopping, but this has a quick return loop built in.

Flushing the whole system through to remove the veg oil would take quite a while, and it really does need to be clear to avoid splodgy start ups...

Our conversion cost £500 and paid back after 25 tanks. (Jeeze we use a bit).. If they fit it for you, it will cost approx £1000 (so 50 tanks).

The conversion works thus:

-Start up on diesel, wait till heaters blow hot (or gauge steady at 11).
-Turn knob, aux/top-up heater light comes on if needed. you are now on veg.
-1 mile before home switch back, quick purge clears fuel system back to veg oil tank to avoid diesel contamination.
-switch off at end of journey ready for re start.
-If you forget and switch off before purging it buzzes at you and you need to restart and run at sustained high idle for a couple of mins... I don't forget anymore....
if you spend a bit more and get a smart-veg one, it does it all for you.

Fuel from wholesale about 70ppl at the mo, was cheaper till this summer, shouldn't encourage you really, it makes my fuel more expensive

andyfb78 wrote: I am currently experimenting with food flavouring to see if I can change the exhaust smell!!!!

Now that is original!...I like that form of forward thinking andy,it sounds like a great set-up you have there...

I think i'm the only one on forum that thinks the diesel/veg oil smell is like the whiff of doughnuts being made...i dont think it smells of chips really,but thats just me i guess....

I actually quite like the smell!

I'm certainly no expert, but am i right in thinking that a pre-mixed diesel/veg oil fuel can be added to the fuel tank on a stone cold bongo?

I hope so, cos thats what i do!

In my experience, i have had no evidence to suggest that the veg oil sinks to the bottom of the tank, nor, to the bottom of the part transparent containers i store the pre-mixed fuel into...It appears to be the same from top to bottom, no matter how long it has stood,or the ambient temperature.

I even ran the stored pre-mixed fuel through a viscosity cup on a few occasions, and have the same flow rates uniformly from the top,to the bottom of the containers i use, i assume this to extend to the fuel that is in my fuel tank?

In other words, i'd suggest that once mixed, it stays mixed.

mikeonb4c, PM me your phone number and will try to answer any questions you have.

Andy, I am aware of the engine oil that tollerates veg oil, but the problem in my view is if veg oil gets into and past the rings. Over time the rings can gum up and seize.
Keeping engine and veg oil apart must be the best option.
Agree twin tank system is the only long term way to go.

B D C did you test the viscosity of diesel only, veg only and mix?