Warning to SVO users [Archive] - Land Rover UK Forums

Snagger

29th Jun 2008, 18:01

This is the state of one of my pistons after 2,500 miles from new, with SVO use on only about 1,000 of those. The other three were similar. This is despite running with a fuel heat exchanger and making sure the SVO was only selected with a warm engine. The carbon deposits on the side of the crown have already made a few polishing marks on the bores, and much more may have lead to scoring.

I will be investigating carbon deposit reduction methods before (if) I use SVO again, but it's clear that these engines do not respoind as well as reputed. Turner Engineering said this issue is very common with engines running on alternative fuels, be it vegoil, bio-diesel, bio-ethanol or LPG.

Paul Humphreys

29th Jun 2008, 18:24

Not see it on LPG cars but see pictures and heard of it lots with veg oil.

Paul

Dave_243

29th Jun 2008, 18:25

Interesting

I work at a petrol station and my boss has always said that biofuels (even the ones you get at a garage) are highly corrosive to an engine. I, sort of, didn't really take any notice of her but I guess you've proved her right!

Snagger

29th Jun 2008, 18:27

It's heavy, very rapid coking, rather than corrosion, but it doesn't look good. That was not the worst piston either, though it wasn't much different from the worst. I also found two broken oil control rings, but I don't think it's related.

Mud-Bud

29th Jun 2008, 18:30

Bloody hell:eek:

If you use something like Texaco fuel additive thats sort of ment for once every 6 months with every tank of svo would it solve it, or evry couple of weeks maybe as it decokes the injectors and stuff, so might help keep the pistons clean?

Oli

Snagger

29th Jun 2008, 18:38

Rich_P

29th Jun 2008, 18:41

That's some results there. :eek: I take it you've stripped the engine down again then? :confused:

Paul Humphreys

29th Jun 2008, 18:46

I take it you've stripped the engine down again then? :confused:

No Rich, he used a teleportation device to get the piston out without striping the engine:p:D:D:D:D:D:D;)

Paul

Big Sandy

29th Jun 2008, 18:49

That's the sort of thing I want to find out - will regular fuel additives in reasonable concentrations help keep the innards clean... I like the Millers diesel additive. It can be used in two concentrations - one for regular use, and a double dose for thorough fuel system cleaning. It's also meant to clean the cylinders and pistons a bit and increase the cetane rating and burn efficiency of the fuel. However, if these carbon deposits are a result of the fats in the SVO, then I don't know if the additives will work.

You might be interested in Diesel Aid, from United Diesel (http://www.uniteddiesel.co.uk/diesel-fuel-treatment.php) too Nick. Give them a ring (numbers on the website) and have a chat with them, they are very helpful.

All these additives are cetane improvers, but as United Diesel actually manufacture the additive, they may have more info for you.

Snagger

29th Jun 2008, 19:32

No Rich, he used a teleportation device to get the piston out without striping the engine:p:D:D:D:D:D:D;)

Paul:D:D:D

Yep, the head is off (still fitted with its manifolds and injectors), the sump and ladder frame are off the bottom, the pistons are out and I'll be opening up the timing case to double check that the cam shaft sprocket hasn't jumped a tooth. It's all because I'm not happy with the opil consumption and the amount of oil coming out of the breather, even though it only breathes half the amount my 300Tdi does (with no oil loss).

Thanks for the lionk, Sandy - I'll follow that up.

TEMPL4R

29th Jun 2008, 19:35

The 2 broken oil rings are the problem Nick, but as you say, it's worth double checking everything while you're in there.

Chris

Snagger

29th Jun 2008, 20:05

The 2 broken oil rings are the problem Nick, but as you say, it's worth double checking everything while you're in there.

ChrisI only found the rings because I pulled the pisons to decoke them and check for ring damage causing the polishing/scoring... It's just as well that I did this now, before any damage was done to the bores. Caught it in time.;) Shame that SVO seems to clag things up so much - even at 80p/L, it was much less painful to pay for.

justMike

29th Jun 2008, 20:30

even at 80p/L, it was much less painful to pay for.

every silver lining has a cloud...

I could never resolve the chemestry of burning SVO in my head... couldn't reconsile why it would work straight outa the tin here, yet the yanks prefer to treat it; seperate the long chain esters from the volatile liquids to create a more diesel-like fuel... All that clinker around the piston crown shows what happens to them..

I'm guessing that any additive you add to SVO is gonna have its work cut out for it; in chemical terms, it needs to "crack" those long chain fatty acids into far smaller molicules, then further modify them to burn faster and cleaner... it usually takes a refinary to handle that process...

baz

29th Jun 2008, 22:30

How about a bit of nitrous oxide to supply the extra oxygen to burn.
Does anyone running SVO adjust the fuel air ratio?

JimGNR

29th Jun 2008, 22:39

I posted on here over a year ago about the problems I was having with a 300TDi running 10-20% SVO. The injectors were clogging up with carbon after only 1000-1500 miles. I gave up after the second set of injectors because at £35ish per injector it was not a viable alternative to dino diesel. I always use additives too, at quite a strong rate because I sell it I get it cheap so don't mind using the stuff.

People on here poo pooed it saying it was not the SVO as they have been running 100% SVO for decades with no problems.

So if my injectors were clogged with carbon I guess the pistons and valves would have been too.

littlelegs

29th Jun 2008, 23:09

Snagger

30th Jun 2008, 06:45

This carbon can be caused by any number of things even slow driving, you can't point the finger just at SVO without proof, especially as your engine obviously has oil burning mechanical problems which would more than likely be the first cause. An engine is a heat machine and a frequent good run burns off any normal fuel related carbon but the engine can't deal with the carbon from continual engine oil burning or always pottering about. There is obviously also a sensible limit to the amount of SVO/diesel mix ratio that can be reliably used, related to how hard it's driven.
The rings in cylinders 1 and 4 are perfect, but they had the worst carbon deposits. This problem is not due to the engine itself. The injectors and injection pump were rebuilt by a reputable company at the same time as I did the rest of the engine, so spray pattern and timing were also not at fault. While driving style, especially excessively gentle driving, will cause problems, I can't see it happening over 2,500 miles.

Jim, I also had adverse effects on my unmodified 300Tdi when I tried a 50% mix a few summers ago - the rpm was hunting in the mid range by about 500rpm, and though I quickly diluted the mix as much as possible, put several bottles of treatments of Millers diesel additive through, it has never been the same since - the hunting is very small, but still present, and I get a lot of judder in 4th when accelerating from low revs which didn't used to be the case.

PinkSeriesIII

30th Jun 2008, 07:33

Was this Soya based SVO ?

How well was the system purged before shut down and how do you know?

littlelegs

30th Jun 2008, 07:45

I've had another look at your piston picture and although it's not very clear it doesn't look too unusual and the top ring appears free, the carbon ring helps to seal it and I've seen worse on a straight petrol engine! Rings can carbon up on any fuel if it was going that way but it's usually due to burnt engine oil caused by wear or broken/sticking rings. If you've put new pistons and rings into a worn, glazed cylinder, they are not going to bed in properly and will burn oil. I don't know the engine history but the fact that after 2500 miles you've got high oil consumption and broken rings means to me that something wasn't completely right at the rebuild.

Snagger

30th Jun 2008, 19:28

Closer inspection of the two broken oil rings suggests that the broke as the pistons were removed - Frida Turner had a similar suspicion, and she commented on the lack of actual scoring (as opposed to the polishing lines) in the bores as proof of this. This is evidenced by the side on which the circumferencial cracks are - the rings may have caught on on the coke ridge as they were extracted.

The block was rebored and honed for the new AE pistons and rings, and the ring gaps were all set correctly. The injectors and pump were all freshly rebuilt. This heavy coking was not due to engine faults.

It's possible that I haven't been purging the system for long enough at the end of each drive to clear the SVO completely before the next diesel start up - I have been using a 3 mile change over point. However, the point is that this coking is definitely due to SVO, and Frida again told me this morning how they can instantly tell which engines have been using it as soon as they open them up. There are also several other blogs and forums discussing the issue, with this http://forums.tdiclub.com/showthread.php?t=186108 being a very good example with plenty of good photos of his coking and damage. Many respondents on that thread report the exact main symptom I have encountered - heavy oil loss through the breather into the induction tract. Some are trying to blame EGR systems, but that's not the cause - my 200 and 300 engine both lack EGR.

Whether insufficient engine, and thus heat exchanger, temperature are to blame, or whether it's because I left the diesel selection too late in the drive are potential debates, but it's pretty clear that SVO is a lot more troublesome than generally percieved. I will be returning my fuel system to plain diesel and removing the heat exchanger unless I can find an additive that will keep the carbon at bay at an economical price.

Snagger

30th Jun 2008, 20:38

Here's another good article, which also brigs up PinkSeriesIII's point : http://www.biofuelsforum.com/svo_users/4306-veggy_oil_modern_direct_injection_diesel_what_you_ need_know.html

Muttley

30th Jun 2008, 21:27

Snagger

30th Jun 2008, 22:03

Surely the reason it's coking is that your cylinder temperatures are too cool so you are getting incomplete combustion. Particularly seeing this issue is worse in cylinders 1 & 4 (the cooler outer cylinders).

Have a look at putting LPG onto that.. that'll cure the coking problem and give you a lot cleaner burn on SVO (& diesel for that matter) plus you'll get more power :D

That's a good point about the temperatures.

I'd love to fit a propane catalyst injection system, but at over £2k, they're a bit pricey!:eek:

Iv'e been looking through this Aussie forum, www.biofuelsforum.com/svo_users , and many of them seem to have run their various engines with varying levels of success, from completely successful to complete destruction of the engine. What seems to be an issue is the purge time, especially since my return line is looped into the lift pump to dend warm fuel to the filter to prevent waxing and also to prevent tank cross-contamination. It may be that my sustem is only really any good for long trips, with purging being required for the last 10 mils or more.

littlelegs

30th Jun 2008, 22:13

Here's another good article, which also brigs up PinkSeriesIII's point : http://www.biofuelsforum.com/svo_users/4306-veggy_oil_modern_direct_injection_diesel_what_you_ need_know.html

Your first link case seems to be a problem with the turbo causing the initial carbon problem and this could just as easily have happened with diesel. It had also covered considerably more miles than you did.

The second link seems to be more of a rant and a scaremongering exercise and attempts to reverse the characteristics of direct and indirect engines suggesting that the direct run colder and will condense fuel more easily. If this really were the case then the indirect would be the easier to start and it's not because it has the larger combustion surface and loses more heat, hence harder to cold start! He makes absurd comparisons. The direct doesn't need the starting and running devices and is a much more efficient burning engine, unburnt excess fuel would mean it was not set up properly and appear as black smoke which should not be ignored. I don't think this person knows what he's talking about.

I'm not saying you can't have a problem with SVO if you use it wrongly or excessively and choke the engine with it but it just seems that normal mechanical or adjustment problems are being blamed on SVO without any proper evidence to support it. The effects we've seen can just as likely be caused by diesel with too much fuel or not enough air or from a worn oil burner. The only true bit is where once the carbon starts to build up and affects the rings it rapidly gets worse.

You say the rings were broken on removal but the top rings were ok. If the carbon ring was to blame and that bad, shouldn't it have been removed first? I'm sorry if this seems like a grilling but nothing seems to make sense to me and I've been working with diesels for a long time, many of them similarily coked up, usually stationary or marine type that are overloaded. Perhaps you just need to change down a gear more often? :)

RUXY

30th Jun 2008, 23:25

An improved vortex would prevent the carbon sticking -fit a Hiclone - end of problem ;)

justMike

1st Jul 2008, 00:56

It may be that my sustem is only really any good for long trips, with purging being required for the last 10 mils or more.

My change of employer has seen my commute to work go up from 250 to 1000+ miles a month.. eith warm up and purge times like you're suggesting, even with the mileage I'm doing now, it'd never be a worthwhile conversion for me... I'd be able to use oil injection for maybe 2 miles a day..(??) before starting to purge the system...

Honestly not trying to shoot down your system Nick, but along with the chemistry issues, I can't get my head around how 2 totally different fuels with completely different burn charactoristics and BTU content can be injected through the same pump and fuel metering without having to make changes to the metering when you change fuel types.

Snagger

1st Jul 2008, 07:27

An improved vortex would prevent the carbon sticking -fit a Hiclone - end of problem ;)I hope that's a joke! How would a vortex in the snorkel make the slightest difference to fuel spray patterns. Let's leave vortex generators and other snake oil ideas out of this and stick to things that may actually work.

Snagger

1st Jul 2008, 07:37

Your first link case seems to be a problem with the turbo causing the initial carbon problem and this could just as easily have happened with diesel. It had also covered considerably more miles than you did.

The second link seems to be more of a rant and a scaremongering exercise and attempts to reverse the characteristics of direct and indirect engines suggesting that the direct run colder and will condense fuel more easily. If this really were the case then the indirect would be the easier to start and it's not because it has the larger combustion surface and loses more heat, hence harder to cold start! He makes absurd comparisons. The direct doesn't need the starting and running devices and is a much more efficient burning engine, unburnt excess fuel would mean it was not set up properly and appear as black smoke which should not be ignored. I don't think this person knows what he's talking about.

I'm not saying you can't have a problem with SVO if you use it wrongly or excessively and choke the engine with it but it just seems that normal mechanical or adjustment problems are being blamed on SVO without any proper evidence to support it. The effects we've seen can just as likely be caused by diesel with too much fuel or not enough air or from a worn oil burner. The only true bit is where once the carbon starts to build up and affects the rings it rapidly gets worse.

You say the rings were broken on removal but the top rings were ok. If the carbon ring was to blame and that bad, shouldn't it have been removed first? I'm sorry if this seems like a grilling but nothing seems to make sense to me and I've been working with diesels for a long time, many of them similarily coked up, usually stationary or marine type that are overloaded. Perhaps you just need to change down a gear more often? :)Tdis do run cool, while 12J don't, so his logic seems to fit. There are other aspects of his arguement that also make sense about the advantages of iDi.

As I said, the compression rings are fine - it's only two of the oil rings that are damaged, and the lack of scoring on the bores strongly suggests that this was caused on piston removal as the rings caught on the coke lip - they're much more delicate than the compression rings. It's not impossible that I damaged them while cleaning the piston crowns, though unlikely.

The point is that the coking is not a product of an engine fault. Reading those Australian site threads points more and more towards it being an insufficient purging period at the end of the run, which will render my dual fuel system useless on the commute and only effective on long runs. It's still worth having, but it's a shame I can't benefit on my commute. If it's possible for me to fit a quick purge system of some sort, then this may help, but that will need electric pumps and solenoid controlled change-over valves, including for return lines - I'd have to completely redesign my fuel system.

littlelegs

1st Jul 2008, 08:26

Tdis do run cool, while 12J don't, so his logic seems to fit. There are other aspects of his arguement that also make sense about the advantages of iDi.

As I said, the compression rings are fine - it's only two of the oil rings that are damaged, and the lack of scoring on the bores strongly suggests that this was caused on piston removal as the rings caught on the coke lip - they're much more delicate than the compression rings. It's not impossible that I damaged them while cleaning the piston crowns, though unlikely.

The point is that the coking is not a product of an engine fault. Reading those Australian site threads points more and more towards it being an insufficient purging period at the end of the run, which will render my dual fuel system useless on the commute and only effective on long runs. It's still worth having, but it's a shame I can't benefit on my commute. If it's possible for me to fit a quick purge system of some sort, then this may help, but that will need electric pumps and solenoid controlled change-over valves, including for return lines - I'd have to completely redesign my fuel system.

You may well be right about insufficient purging and you can't do that properly if the return is not also controlled but that's an installation fault not an SVO problem as such. It may also be you are switching over to SVO before the engine is ready for it. Can you tell me what you mean by "TDis do run cool while 12j don't" do you mean the combustion temperature or coolant temperature and why you think this is?

Muttley

1st Jul 2008, 10:32

Keeping on with the issue of coking up.

Got to agree with a previous comment about putting a different fuel into an engine without having to alter the timing or fueling. Diesels are a fundamentally dynamic closed loop system so making such a major change like altering the fuel will have ALL sorts of unknown effects on the overall balance of the system. A 300TDi is optimised for using a fuel in a very tight set of specifications, a lot stricter tolerances than a petrol engined vehicle has. So no wonder some of them are throwing chuckies, the key question on the TDis that are lasting the course is to investigate tham and find out what was done differently in comparison to the ones that fail.
SVO has a far lower calorific value than Diesel (i.e. it doesn't contain as much chemical energy. hence it will burn cooler). Vis-a-vis the coking issue. Which is why I made my suggestion about propane injection.
In my opinion the issue of purging has NO effect on the coking issue. Purging is done to ensure that a) the injection pump and injectors are kept in perfect running order b) to insure that cold start performance is optimised. Coking is a timing/fuelling/burn temp issue.I was looking at some of the articles mentioned here and they seem to be from predominantly WARM countries with a higher ambient temperature all year. I was looking at some of the kits availible and it seems to me that the heat exchangers are hopelessly small for the sort of weather we are subjected to in the UK and thats without taking into account the HUGE difference in average temperatures accross the UK. A system designed by a company located in the midlands is not going to perform anywhere as well in somewhere like the Highlands of Scotland. Conversely though a system optimised for use in low ambient temperatures (say Scandinavia) should work readily all over the UK.

BUT in order for the systems to work efficiently they must take account of the timing and fueling changes required when running between SVO and Diesel. System control is the key to it coupled with ensuring that the cylinder temperatures are kept higher than when running on SVO to account for the lower calorific value of SVO to ensure that engines don't coke up.

I am a huge fan of alternative fuels (as some of you will remember) but from what I'm reading there seems to be a fundamental failure in the understanding of how these systems operate which is resulting in long term issues. I'm not talking at a mechanical level... there is a lot of knowledge here of how they work and how to get them to work, where the knowledge is missing is at the systems level and the relationships of system components on each other - that takes a LOT of dedicated research (hence boot fulls of dosh) and a lot of clever people to optimise the technology.

It's the same with any type of new technology, it is going to be as unreliable as heck in the early years but as the knowledge base grows the technology will be modified to cope... it's just unfortunate that Snagger's motor is one of the casualties to this science :p

It could be something as daft as moving a flap accross 50% of the rad when running on SVO to up the cylinder temp or somthing as mundane as changing the thermostat that could be the key to the coking issue.

PinkSeriesIII

1st Jul 2008, 10:33

My system is twin tank (110 tanks at rear and 90 under driver seat) with two solenoid valves for the fuel selection and return lines.

I do not loop the return as it leaves an X amount of SVO cycling in the system for X amount of time/miles.

I return SVO and diesel separately to their respective tanks (expect during the initial 30 second of the purge cycle, where upon switching to diesel the fuel is returning to the SVO tank to help prevent contamination of the diesel then the valve is switched to return to diesel tank as normal).

I run two separate standard fuel filters, 1 for SVO, 1 for diesel, this removes the filter from the purge time.

The heat exchanger is before the SVO filter, thus removed from the purge time also.

The fuel selection valve is located after the filters. The Lift pump is plumbed to PULL fuel through whatever filter is selected. The heat exchanger (flat plate water) is there to ease fuel through the filter in winter and to take stress off the lift pump. Heat exchangers on landrover TDI's have no other practical roll in the system than that - something which is discussed elsewhere on more dedicated forums.

A better arrangement would be a water heated fuel filter in the normal position and a FPHE on the SVO return line to help in winter (I have not - yet). Also could have reduced purge time even more by having separate fuel pumps but have chosen not to complicate things unless needed.

It is DIFFICULT to know when system is purged. Sight glass, experimentation etc to try and work out what is required and then add some safety factor. I have not gone fully into that - would not mind some help with ideas. Like knowing the return flow rate at idle - and under load. On the landrover TDI the return flow is HIGH - forget to switch the return from flush and the diesel tank empties quite fast - but no figures as of yet. But return rate though important for knowing when the return line is flushed does not relate to when the injectors/cylinders will get flushed with diesel.

Based on the smell of the exhaust my setup has stopped burning SVO after about a 1 mile of rural of open roadway. So after switching over to diesel I do the 30sec count to flush the return line before switching the RETURN to diesel tank then at least 2 miles drive before shutdown.

Would there be way of knowing EXACTLY when engine in no longer running on SVO by measuring echaust with an emissions meter?

Would a dye in one of the fuels and a sightglass help calculate accurate return flush times?

Is there an electrically conductive fuel additive that could be mixed to the diesel so that the derv/svo ratio can be calculated with an ohm meter? (I read such additives are used as anti static safety device in aircraft fuels).

Any other way?

Such experimentation would not even need to be perm installed, just at the beginning to get an idea of times involved.

I do not like the guess factor involved, and the 'smell' method being my own solution is kinda scary.

PinkSeriesIII

1st Jul 2008, 10:45

Keeping on with the issue of coking up.

In my opinion the issue of purging has NO effect on the coking issue. Purging is done to ensure that a) the injection pump and injectors are kept in perfect running order b) to insure that cold start performance is optimised. Coking is a timing/fuelling/burn temp issue.

It is stated that the purge (in regard to Landrover TDI's) is to ensure that upon a cold start there is no SVO remaining in the system (IP > injectors >cylinders) so that no SVO is injected onto stone cold pistons which is main cause of of polymerisation/coking issues. Is that incorrect in your opinion?

Muttley

1st Jul 2008, 13:06

It is stated that the purge (in regard to Landrover TDI's) is to ensure that upon a cold start there is no SVO remaining in the system (IP > injectors >cylinders) so that no SVO is injected onto stone cold pistons which is main cause of of polymerisation/coking issues. Is that incorrect in your opinion?

No thats probably right as well - hey I'm stumbling about in the dark as well here :D it certainly makes a lot of sense as far as the cold running coking issue.. I'd read that there had been mechanical issues with the Lucas IPs on cold start as opposed to the Bosch ones which is why they were purged on diseasel to ensure adequate lubrication on start up.

As for you control system wish list thats fairly easy to sort out I would have thought that even a stock Lamda sensor in the exhaust would be able to tell the difference by sensing the O2 content in the exhaustate, commisioning the system would be easy as well. Fire up on diseasel and measure all the levels from the sensor, once warm swap onto SVO and note the changes - I would expect there to be a major difference (NOTE that is a theoretical expect ;)). A simple feedback loop to the system controller would then be able to automate the pruge system;
set to purge-->wait until the levels from the exhaustate return to diesel levels then the system would be safe to shutdown.
You could also put an alarm in the system to trigger on the handbrake warning light just so the driver was aware that the system purge hadn't completed if the vehicle parked up.

The system Lektroniks is the easy peasy part :D (well for me that is basically what I do for a living - control systems) its the plumbing thats the tricky bit.

Ideal prototype system hydraulic design from my point of view would be tank set up as PSIII describes but with atmospheric temperature dependant electric tank heaters in the SVO tank. twin heated fuel filters for both fuel types (improved cold start performance even when the weather is really baltic and gets heat into the injection pump quicker to allow a quicker swap over onto SVO). Flow meters in the input lines from each tank and in the return loops. Some form of flow control manifold block (heated again) with the solenoid valves on it (looks tidier easyier to maintain). I'd also put a proportional control valve in on the coolant circuit to the rad and ditch the thermo mechanical stat to give more precise engine temp control.

Control system would take account of flow rates, ambient temp, water temp of block and rad as well as fuel temp , and revs. Swap over onto SVO would be only at optimum point (driver could hit SVO on start up but system would only swap to SVO over when it thought it was ready to). I'd be tempted on the prototype to use block and head temps sensors as well as exhaust gas temp anylisers just to see what was going on.

Heck you could even use an aromatic gas sensor near the end of the exhaust to sniff for "eau de chippy" as well. :eek:

Run it for 6 months with a data logger attached and see what you get from the figures.

PinkSeriesIII

1st Jul 2008, 13:20

As for you control system wish list ...

okay backing up a bit before going into pseudo-fantasy automated control systems ($$$)...

Lamda sensor, that sounds like something to look into and if promising should be simple to install to the point of just monitoring the sensor output. I do not need to automate - manually indication is suitable at this point in time.

I'd read that there had been mechanical issues with the Lucas IPs on cold start as opposed to the Bosch ones which is why they were purged on diseasel to ensure adequate lubrication on start up.

yes, and the reason why the HE is irrelvant to the landrover tdi as the IP can handle stone cold svo, plus pre-heated svo has no impact on the IP in these engines - the IP will dictate the temp of the oil soon as the oil hits it. Hot SVO into COLD PUMP= COLD SVO (anyway that all been beating out on other forums, no need here).

PinkSeriesIII

1st Jul 2008, 13:38

Lamda sensor, that sounds like something to look into and if promising should be simple to install erm or maybe not:( need someone to stick a emissions analyzer up the exhaust and see if there is a measurable difference if good to go then Halifords even sell them and coudl be rigged up for on road testing?

Muttley

1st Jul 2008, 15:02

erm or maybe not:( need someone to stick a emissions analyzer up the exhaust and see if there is a measurable difference if good to go then Halifords even sell them and coudl be rigged up for on road testing?

Sounds like a plan.... but you do realise that a lot of Lambda sensors work in the millivolt range...:)

And I suspect that most off the shelf gas anylizers don't have the sensitivity required especially from halfrauds. BUT hydrocarbon emissions, particulate matter, CO2/CO may show a significant difference.

justMike

1st Jul 2008, 22:56

Heck you could even use an aromatic gas sensor near the end of the exhaust to sniff for "eau de chippy" as well. :eek:

Run it for 6 months with a data logger attached and see what you get from the figures.

now THAT would be one hellova system... come to think of it, the stuff I'm building at work could be adapted to do the job exactly as you spelled it out...

hmmmmm...

you're lookin for a medal, aintchya...?? eh....???????

:p

Snagger

3rd Jul 2008, 18:09

Some good nuggets there.

The heat exchanger is installed in the fuel system to thin the SVO for two reasons: to reduce pressure induced damage to the injection system and to ensure a good spray pattern for complete burning of the SVO. Low temperature fuels are not too much of a problem for the Tdi's injection system, but can be fatal to the earlier 12J and 19J Lucas systems. The low temperature causes a bad spray on both systems, though, and results in the coking and oil polymerisation (worse on Tdis than the iDi 12/19J).

I have not been using palm or soya based oils - they are terrible for coking. What is interesting, reading other forums, is that those who suffer problems all seem to get the same main symptom I got - the heavy oil contamination of the induction system, even if the breathing isn't particularly heavy.

As far as the calorific valeu of the fuel is concerned, I'm really not worried from a performance point of view - a Tdi in a Series LR is a huge improvement, and any slight degradation in performance from SVO is still massively outweighed by the engine enhancement. A slight reduction in torque might not be a bad thing for the gearbox, anyway.

I'd be interested to see what the inside of more successfully run engines are like. I am becoming more and more confident about this being a purging issue. My Tdi is standard, as is its radiator and thermostat. they are not altered by other SVO users, so mine should also be fine.

What is different about my vehcile is the fuel system itself. I use the rear tank for diesel, and the two front tanks (ex MoD underseat type) for rape seed SVO. I have ex-MoD style taps on the front of the seat base to select which tank is in use, and an associated return line valve is attached to the feed valves to automatically match deleivery and return lines to the same tank. The fuel line from the feed selector valve then runs to the lift pump, through the filter, into the heat exchanger and into the injector pump.

The return from the injector pump was Tee-ed into the lift pump feed to prevent tank cross-contamination when the Tdi was fitted (having previously run to the eturn line tank selectors), and to ensure some warm fuel went through the filter to prevent it clogging on SVO.

I think the problem is that the looped return is preventing full purging of the SVO from inside the engine bay, and so the engine is starting on a diesel/SVO mix.

I will be reconnecting the full return system and will also redesign the supply system so that the diesel will run from the tank, through the lift pump and filter, to the feed selector valve and then the injection pump, while the SVO will run from tanks through an electric pump, the heat exchanger, a dedicated filter, and then to the selector valve an injection pump. This will ensure the vest amount of fuel between the feed selector valve and the injection pump, and so the quickest purge with the least cross-contamination of tanks (being mechanically paired, I can't set the return valve to operate in a delayed fashion to the feed valve). This will also mean that the diesel is no longer heated before the injection pump - the pump makes some slight tinkling noises on hot diesel, and the spray pattern of the thinned diesel may also be a problem

I may take up the idea of a sight glass in the return line, and enquire about fuel dyes to make some test purges for timings/mileages. I'll also add some diesel additives to the SVO to try to keep things clean.

yostumpy

4th Jul 2008, 19:11

Why not just run it on a straight 50/50 mix straight into the tank, No problem on mine! 300tdi. Then take the fuel pipe from the lift pump up and wind it round the top metal heater pipe next the intake manifold to the filter. placed on the bulkhead near the exhaust, then fuel pipe back again along the heater pipe again to the injector pump. Then put a 300 tdi rubber cover on the top and you have an insulated double heaated system, combined withan inline glow plug type heater near the ij pump. This should do the trick!

Snagger

4th Jul 2008, 21:38

That will not work, and 50% mixes on single tank systems will coke the pistons, valves and injectors.

yostumpy

5th Jul 2008, 22:41

Wat wont work and how do YOU know!

Snagger

9th Jul 2008, 14:42

Wat wont work and how do YOU know!Yo are still injecting SVO into a cold engine, and that is the problem.

Why do you think that me shutting down and cold starting on less than 10% SVO mix will do more harm than running routinely running on 50%. Why do you think that there are so many companies installing expensive multiple tank systems, if all that's required is to run a 50% mix?

Take the head off your engine and have a look at the mess inside - that's why I want a proper system.

yostumpy

10th Jul 2008, 18:24

money,money,money.

Snagger

10th Jul 2008, 18:48

money,money,money.OK. All that coking in such a small mileage was just my imagination, and what would Turner Engineering know about engines anyway?:rolleyes:

For all thread readers interested in SVO use and NOT damaging their engines, do not run them on SVO without a heat exchanger system and twin tank system - the Tdi injection system will not break from the cold fuel, but the insides of the engine will coke up badly. Anyone can just throw SVO in the tank and shout that it works, but they don't realise what they're doing to their vehicle.

The whole point of this thread was to productively share information and experience that running on SVO is much more involved than just throwing the stuff in or even using a simple mutli-tank system with a heat exchanger and sahared pumps and filter - you need dedicated separate fuel systems all the way to the selector valve which immediately supplies the injection pump, so you need separate filters, LP pumps and the like.

ianhl

10th Jul 2008, 19:16

the Tdi injection system will not break from the cold fuel, but the insides of the engine will coke up badly. Anyone can just throw SVO in the tank and shout that it works, but they don't realise what they're doing to their vehicle.

i think you are right nick. since i installed the dieselveg twin tank kit in our 300tdi we have forgotten to switch over to diesel two or three times. starting in the morning was difficult to say the least! it doesn't break but it takes some cranking...when it fires up tickover is lumpy and horrible, it really doesn't like running on veggie from cold and i switch straight back to the diesel tank and allow the engine to warm up before it switches over. if you know anything about engines you will know straight away that things are not working properly...

thanks for posting your experience, it is useful to anyone who is interested in alternative fuel sources in the long term...it has made me think about my purge timings and my switchover timings if we leave the disco parked up for any length of time.
i think it is a shame that people feel the need to argue any point made here, it is useful info for people who are running on svo and want to get the best from the fuel on a long term basis...

thanks again nick.

RUXY

11th Jul 2008, 11:56

About this time last year I was trawling the internet (mainly French & German sites) looking at kits, plate heaters etc.
However I lost interest when the government changed the tax rules permitting about 10,500 miles SVO running without keeping records. At the time it seemed to me they were willing further people to empty supermarket food shelves until the prices were so near the DERV pump price people would loose interest in a trolley full of cooking oil.
To me - this is what has happened, it is now not an economical investment to buy the kit required to do the task without risking a good engine.
If you have an old banger - go for it, an old French car :eek: will probably run for ever with little modification if any :D

PinkSeriesIII

11th Jul 2008, 15:09

To me - this is what has happened

The amount of people who can use and then do use SVO as an alternative fuel in their vehicle is tiny and has very little bearing on the current price rise in vegetable oil markets world wide. SVO is not an attractive fuel alternative for the majority of joe public with modern direct injection engine due to the modifications required so the actual demand will peak low (unless manufactures include into design of new vehicles).

What is a factor is that rice prices have gone through the roof due to a shortage and thus Asian markets have switched demand from rice oils to cheaper alternatives. That and we are also told that UK rapeseed crops largely failed in last couple of years - (wet summer of 2007).

On a side note, a nice article to read which although does in part contradict what I say above is this ...
http://www.biofuelwatch.org.uk/foodcrisis.php
Makes clear all is not rosey in the garden, but possibly scare tactic propaganda by certain bodies.

RUXY

11th Jul 2008, 16:36

I hope the amount of people who can use and then do use SVO as an alternative fuel in their vehicle is tiny, in particular if it is purchased from food shelves. I have no problem with set-aside land being taken back into production for oil crops that are a genuine addition to propulsion oil stocks ;)

ianhl

11th Jul 2008, 18:00

in particular if it is purchased from food shelves.

use of veggie oil bought from "food shelves" in this country has very little effect on world food prices or shortages...
look at the biofuelwatch website and take the time to read it, the big problem is the large agribusiness corporations who will do anything for their dollar regardless of the consequences. people who are taking a backyard engineering route away from diesel use are contributing positively towards reducing pollution and reliance on finite resources...;)

RUXY

11th Jul 2008, 20:31

There was bulk buying (for vehicles) from Makro , Costco etc. it's only the rise in prices that slowed it, supply / demand will always regulate the price of any commodity.

ianhl

12th Jul 2008, 07:55

There was bulk buying (for vehicles) from Makro , Costco etc. it's only the rise in prices that slowed it, supply / demand will always regulate the price of any commodity.

the purpose of macro/costco type outlets is bulk buying at discounted prices:D
i will always try to source oil at the best price (as you will your fuel of choice) in march mr tesco was knocking it out at .51p/ltr and he kindly delivered 80 ltrs to me...hopefully they will repeat this offer soon.
i am happy with my oil at .95p/ltr at the moment, i would choose to run veggie rather than diesel even if veggie was the same price as derv...bigger picture and all that;)

RUXY

12th Jul 2008, 08:44

Putting aside the ethics of using supermarket shelf oil (I am moving to mains gas and had been considering using an old 600 gal. central heating oil tank for bulk supply of rape seed oil). I have just checked the Tesco website and there is no cheap shelf oil now and I doubt if there will be in the future.
My main consideration was the return on investment period for buying a good kit so as not to damage the engine - however after reading up I came to the conclusion that there would be problems.
About 1980 a farmers coop based at Darlington (Farmway) with large seed interests experimented on their own mixed fleet and could not resolve all issues so discontinued.
The point being was that they intended to IIRC to use both rape oil and linsead oil and sell it back to their members / customers, they wanted 100% assurance that it would not harm engines. They eventually gave up - problems mainly being injection pumps but also coking up, nothing seems to have changed this last 25 years and therefore IMHO save it for old cars / engines where you have little to loose financially.

Snagger

12th Jul 2008, 15:54

I fitted second hand front tanks to my 109, along with a pair of second hand ex-MoD tank selector valves. The cost of all that was less than £100, and it was done during the main rebuild to increase range without the nedd for Jerrycans (I wanted to reduce the size of the can lockers and use them for oil and water instead of fuel).

It was only nearing completion of the rebuild that i started looking into SVO use, and the only addition I made to the fuel system was a new heat exchanger for £60 - less than a full tank of fuel.

It now transpires that I need to add a dedicated SVO filter and lift pump, and re-route the pipe work. I have plenty of 6mm fuel line and the fuel filter assemblies from my old 12J and 19J engines - the only item I need to buy is an electric pump.

I will have a properly configured system for a meagre outlay of less than £150 over what I had already installed for running on Derv, and only £250 for a full three tank system. With 42 Gallon capacity, that cost will pay for itself within three fill-ups at current prices (or less than two fills considering I'd already bought many components for non-SVO use). You can't argue with the economics of that.

As for the increase in SVO prices, that reflects the increase in production and distribution costs - the farmers, precessors and hauliers all need to cover their increased costs of fuel or energy.

Snagger

12th Jul 2008, 16:01

i think you are right nick. since i installed the dieselveg twin tank kit in our 300tdi we have forgotten to switch over to diesel two or three times. starting in the morning was difficult to say the least! it doesn't break but it takes some cranking...when it fires up tickover is lumpy and horrible, it really doesn't like running on veggie from cold and i switch straight back to the diesel tank and allow the engine to warm up before it switches over. if you know anything about engines you will know straight away that things are not working properly...

thanks for posting your experience, it is useful to anyone who is interested in alternative fuel sources in the long term...it has made me think about my purge timings and my switchover timings if we leave the disco parked up for any length of time.
i think it is a shame that people feel the need to argue any point made here, it is useful info for people who are running on svo and want to get the best from the fuel on a long term basis...

thanks again nick.

Ian, I'd suggest you use a strong dose of a good fuel and engine cleaner before you get the same bore scrubbing as I got - it takes very little time, and starting just a couple of times on SVO may have been enough to develop significant coking already, based on my experience and comments on that Aussie SVO forum. I used STP fuel system cleaner - their promotional photos on the bottle suggest that it removes a lot of coking from the pistons and valves as well as the injectors. Other cleaner brands didn't mention piston cleaning at all. I'll be using Millers diesel additive in the SVO in the future, once I have reconfigured the fuel system.

PinkSeriesIII

12th Jul 2008, 16:47

due to the increased viscosity of rapeseed over soya oil I have recently encountered problems on my setup with using the standard lift pump alone (pulling from rear tank on 110) since I changed brand/oil type.

Runs okay on open road, hates it on low revs esp when going up or down hill in 1st/2nd lowbox with stalling/fuel starvation. Have added 30% diesel to the SVO tank to help it along for now and the issues have gone. Do not want to go back to soya oil though.

I have the electric fuel pump (facet) from an early petrol 90 which I guess I will put near the rear tank as a booster to aid the mech lift pump. Pain as it needs locating and plumbing and also wired to only come on when SVO is selected. Didn't really want to extra liability of an electric pump esp stuck outside on a 4x4 offroader, but hey ho - I am guessing I would be completely screwed in winter without.

My other option is to use the 90 underseat tank for the SVO and the rear tank for Derv with the hope that the shorter distance would not cause a problem for the liftpump. Would also be easier to switch to larger bore fuel lines from the front and locate a electric pump in a more protected location.

Or I could buy a 3 quid 8mm hose connector and use that to bypass the heat exchanger and just use diesel in both tanks. Write off the SVO experiment as a fun experience and be left with a cool twin tank long range fuel system.

littlelegs

12th Jul 2008, 17:15

due to the increased viscosity of rapeseed over soya oil I have recently encountered problems on my setup with using the standard lift pump alone (pulling from rear tank on 110) since I changed brand/oil type.

Has anyone ever considered a tank heater to thin out the oil and aid pumping? Could be run from the cooling/heating system with a pipe within a pipe heated/insulated fuel pipes all the way to the pump and beyond and might even do away with the heat exchanger.

Paul Humphreys

12th Jul 2008, 17:27

Might be hard to get one in the tank. But HGV in cold places have heated fuel lines.

Or a heater next to the tank.

Paul

PinkSeriesIII

12th Jul 2008, 17:44

Has anyone ever considered a tank heater to thin out the oil and aid pumping? Could be run from the cooling/heating system with a pipe within a pipe heated/insulated fuel pipes all the way to the pump and beyond and might even do away with the heat exchanger.

That is the system that is popular in the USA, P-I-P and water heated tank and filter.

The thing is... I fear the long runs of coolant hose on a landrover 110 Tdi. One reason is that the 300tdi rapidly goes into meltdown if there is a problem with coolant (been there, done that $$$$). It concerns be already having the flat plate heat exchanger plumbed in - more hose and joints beyond standard = a liability. Another reason is that the Tdi runs pretty cool as it is, would further lengths of hose which would be acting as radiators themselves reduce the temperature to the level where it is unusable for heating SVO? (70 - 90 deg C quoted ideals)

I have seen winterised MOD 110 with little radiator heaters plumbed in all along the rear tub for crew heating... so I guess some one has had long runs working well.

photo here of the rad's http://ihana.com/big_trip/the_landy/images/bk_emptyA.jpg

Snagger

12th Jul 2008, 17:44

It'd also take a long time to heat the fuel tank to a useable temperature. The plumbing would be difficult, and it might use so much of the hot water that you'd not have any flow for the heater matrix.

I'll be using my rear tank on Derv and returning its fuel system completely to standard. I'll be fitting a parallel SVO system with an electric pump before the heat exchanger and filter. Only after exiting their respective filters will the fuel systems converge on the selector tap and then run directly through a sinle line to the injection pump.

This way, the mechanical lift pump will not be under additional strain, the electric pump will only need to be activated when running on SVO, both low pressure pumps will be pushing, not sucking, and the filters will be under positive pressure, not negative, so any leaks in any part of the system except the first fuel lines from the tanks to the pumps will result in fuel leaking out, not air being sucked in (making leaks easy to identify and cure, and preventing fuel starvation).

PinkSeriesIII

12th Jul 2008, 19:24

with an electric pump

what spec pump are you planning on using ?

I been playing with various electric pumps (including fuel) on another project (fuel transfer) and have found that the flowrate of any particular pump is drastically reduced soon as it starts dealing with vegoil. If that reduction would negatively impact upon an installation I do not know.

I assume TD5 in tank pumps are over rated for their job and could be a decent possible pump.

Paul Humphreys

12th Jul 2008, 19:35

http://cgi.ebay.co.uk/FACET-Electric-Fuel-Pump-to-150-bhp-with-FREE-UNIONS_W0QQitemZ120281004447QQcmdZViewItem?hash=it em120281004447&_trksid=p3286.m14.l1318

might do.

Paul

Paul Humphreys

12th Jul 2008, 19:54

Or

http://cgi.ebay.co.uk/NEW-12v-Electric-FUEL-Diesel-PUMP-Solid-Electronic-Bio_W0QQitemZ320273475071QQcmdZViewItem?hash=item3 20273475071

PinkSeriesIII

12th Jul 2008, 20:32

Or

http://cgi.ebay.co.uk/NEW-12v-Electric-FUEL-Diesel-PUMP-Solid-Electronic-Bio_W0QQitemZ320273475071QQcmdZViewItem?hash=item3 20273475071

never liked solid state facets. The facet off the 90 (petrol) is more like this one ...
http://cgi.ebay.co.uk/FACET-SILVER-TOP-COMPETITION-FUEL-PUMP-RACE-AND-RALLY_W0QQitemZ320254042281

Paul Humphreys

12th Jul 2008, 20:37

Use to use them on my Minis ;)

Paul

PinkSeriesIII

12th Jul 2008, 21:03

Use to use them on my Minis ;)

Paul

I remember the mini sometimes used the big SU leccy pump (on the GT 1275cc?), the same pump found on all sorts of UK cars of the era since the 50's. I got one of them tucked away somewhere too.

Paul Humphreys

12th Jul 2008, 21:07

I remember the mini sometimes used the big SU leccy pump (on the GT 1275cc?), the same pump found on all sorts of UK cars of the era since the 50's. I got one of them tucked away somewhere too.

Yes I used one of them as well, from a Jag as I ran twin 1 3/4" SUs from a Jag on an 1480 that reved to 8k :D. But the fuel standard pump was not up to it.

Paul

Snagger

13th Jul 2008, 18:38

I don't know enough about pumps to determine which would be appropriate. I was going to get some advice from the SVO kit fitters.

tony109

15th Jul 2008, 00:03

Snagger

15th Jul 2008, 13:29

Your concerns about coking on a multi speed engine are interesting to hear.. Running a constant speed engine on dripping did cause carbon bumping after around 2 weeks use.. Ive not had any problems with a multi speed engine on veg oils, as cylinder temperatures/ pressures never remain constant.
So has anyone experienced this?

Try looking at this link I put near the beginning of this thread - there's a whole forum of people who've experienced it and some very savvy seeming members who know how to cure it: http://www.biofuelsforum.com/svo_use...need_know.html (http://www.biofuelsforum.com/svo_users/4306-veggy_oil_modern_direct_injection_diesel_what_you_ need_know.html)

littlelegs

15th Jul 2008, 14:58

Try looking at this link I put near the beginning of this thread - there's a whole forum of people who've experienced it and some very savvy seeming members who know how to cure it: http://www.biofuelsforum.com/svo_use...need_know.html

Without seeming to go around in circles here, at the begining I pointed out that this person was unqualified did not know what he was talking about. He was trying to turn around well known facts and characteristics in a rant gleaned from other bright idea amateur websites to suit his case regarding different engines and his comments bore no relationship to actual facts or what I've known or been taught over many years as a diesel mechanic. I don't disagree that some engines will run better on SVO in less than ideal conditions but many of the problems highlighted were unrelated to SVO such as a failed turbo.

Of course it is possible to have problems with any fuel on any engine if it is not used or set up properly as Snaggers was but SVO is not as simple to use as diesel and people don't understand that and are often using short cuts in the use and creating long term problems and I don't think snagger will disagree with that. The secret is easy, always use clean hot SVO in a hot engine to always burn clean and give the engine a good thrash now and then on diesel to burn off any carbon that just might be there. I do this even with diesel and never need to touch the engine or injectors at all as they burn themselves clean, ask any MOT tester which cars easily pass the smoke test, slow or fast driven cars?

littlelegs

15th Jul 2008, 15:55

Without seeming to go around in circles here, at the begining I pointed out that this person was unqualified did not know what he was talking about. He was trying to turn around well known facts and characteristics in a rant gleaned from other bright idea amateur websites to suit his case regarding different engines and his comments bore no relationship to actual facts or what I've known or been taught over many years as a diesel mechanic. I don't disagree that some engines will run better on SVO in less than ideal conditions but many of the problems highlighted were unrelated to SVO such as a failed turbo.

Of course it is possible to have problems with any fuel on any engine if it is not used or set up properly as Snaggers was but SVO is not as simple to use as diesel and people don't understand that and are often using short cuts in the use and creating long term problems and I don't think snagger will disagree with that. The secret is easy, always use clean hot SVO in a hot engine to always burn clean and give the engine a good thrash now and then on diesel to burn off any carbon that just might be there. I do this even with diesel and never need to touch the engine or injectors at all as they burn themselves clean, ask any MOT tester which cars easily pass the smoke test, slow or fast driven cars?

I've read Snaggers link over and over again and I seem to have got hold of the wrong end of the stick on the first post as to what this person was actually trying to say through the unnecessary ranting and long drawn out descriptions. Although he doesn't make it very clear to me or reinforce the point, it appears he is actually trying to say what will happen if you don't use a twin tank system and the effects of cold running. We are in fact saying the same thing. My mistake! :o

Chasesdragons

15th Jul 2008, 16:54

PinkSeriesIII

15th Jul 2008, 17:20

My mistake! :o

did wonder - and started ignoring your input cuz of it :)

Snagger

15th Jul 2008, 17:44

I've read Snaggers link over and over again and I seem to have got hold of the wrong end of the stick on the first post as to what this person was actually trying to say through the unnecessary ranting and long drawn out descriptions. Although he doesn't make it very clear to me or reinforce the point, it appears he is actually trying to say what will happen if you don't use a twin tank system and the effects of cold running. We are in fact saying the same thing. My mistake! :oYep - I think you're now on the same page, so to speak. What that guy was saying is fundamaentally the message that I'm trying to get across, though he has much greater knowledge and experience than I do.

The message is that to run SVO without damaging your engine, you need to ensure you have a system that only injects warm SVO into a warm engine, with a thorough purge system to ensure that the engine starts on 100% diesel, not a mixture of diesel and SVO (regarless of however diluted).

The "just tip it in the tank" advice is dangerous to the longevity of the engines, and users need to be aware of the degree of coking and subsequent bore scrubbing, ring gumming, spray pattern disruption and oil polymerisation that occurs even with twin tank systems if the purging is not 100% effective.

As for the energy content of SVO, I haven't noticed any signifacnt performance reduction compared to running on diesel.

littlelegs

15th Jul 2008, 20:07

did wonder - and started ignoring your input cuz of it :)

Wouldn't be the first time for me, must read more carefully! :)

ianhl

16th Jul 2008, 09:41

Ian, I'd suggest you use a strong dose of a good fuel and engine cleaner before you get the same bore scrubbing as I got - it takes very little time, and starting just a couple of times on SVO may have been enough to develop significant coking already, based on my experience and comments on that Aussie SVO forum. I used STP fuel system cleaner - their promotional photos on the bottle suggest that it removes a lot of coking from the pistons and valves as well as the injectors. Other cleaner brands didn't mention piston cleaning at all. I'll be using Millers diesel additive in the SVO in the future, once I have reconfigured the fuel system.

nick, we use millers in the diesel tank - can't think why but we have never put it in the main veggie tank, going to start now though. i will give the stp fuel system cleaner a go...its something that i would normally use every year pre-mot.

RUXY

17th Jul 2008, 12:53

Regarding the original post about knowing when the Diesel system has taken over. Why not install a vacuum gauge? This will drop towards 0 when diesel is starting to cycle through and it will also let you keep an eye on any system stress when running WVO/SVO (higher than parameter vacuums due to oil viscosities and filters starting to clog up)

We are just dragging through a 100" Lightweight project using a Discovery 200Tdi base. Thankfully it comes ready with a twin tank system. FPHE etc is ready to be fitted.

There is supposed to be only 65% energy in VWO or SVO in comparison to Dino. Despite the fact that it is burnt more cleanly. I have a feeling someone is pulling the wool over my eyes here - WVO/SVO is slow burning. I think there is a lot of injected fuel that is going to be burnt off in the exhaust, dropping the power further....need to read up on atomisation and burn enhancing..

Keep it coming.

Regards
Udhi
------------------------
Regarding energy content you are probably correct but for just running about - car use (and if you are getting your fuel cheap enough) then you will probably not even notice. However if you are doing a bit of heavy towing requiring maximum tractive effort you will probably notice. Filling up with DERV - for me Shell seems to be the best, possibly other brands are using more veg oil ?

Snagger

17th Jul 2008, 17:16

------------------------
Regarding energy content you are probably correct but for just running about - car use (and if you are getting your fuel cheap enough) then you will probably not even notice. However if you are doing a bit of heavy towing requiring maximum tractive effort you will probably notice. Filling up with DERV - for me Shell seems to be the best, possibly other brands are using more veg oil ?No fuel manufacturers areadding SVO to diesel, and I can't imagine forecourt staff adding it in the middle of the night either.

RUXY

17th Jul 2008, 17:25

AFAIK - it is no longer 100% mineral, there is / going to be a statutory minimum for non-mineral oil with an upper addition level above this. It is only the threat of claims for damaged pumps stopping increased levels :eek:

RUXY

17th Jul 2008, 17:39

Snagger

17th Jul 2008, 18:13

Snagger

17th Jul 2008, 18:22

timesonline.co.uk/tol/news/environment/article3740163.ece

There is loads to Google on about Greenpeace having Tesco diesel tested in a German lab. It seems the actual 5 stated in some articles is not correct (bad reporting) but they were using Soya oil.
It seems they do not have to post on the pumps just what the DERV contains :eek:I just read the article, and it states quite clearly that Tesco, like other fuel companies, are blending 5% biodiesel with mineral diesel for the labelled "Green diesel", suggesting their regular diesel is still 100% mineral.

The thrust of Greenpeace's complaint is that of the biodiesel content, 30% is from palm oil, while the other 70% is from soya, and that the use of palm oil is ecologically damaging because of deforestation to grow the palm. This means that in practice, 1.5% of their green diesel is palm oil derived biodiesel, 3.5% soya derived biodiesel, and the other 95% is mineral.

It also makes no suggestion that unmodified vegoil is being blended with the mineral diesel.

Could you please not post in green - it's very hard to read.

RUXY

17th Jul 2008, 19:58

My understanding is that all basic (regular) DERV is now 95% fossil and 5% Bio origin. So in fact all you can obtain at the pumps is B5, what also seems to confuse at the pumps is labels such as City D (ULSD) , Shell V Power Diesel or BP Ultimate Diesel (what was the regular diesel having been dropped) - all this marketing confusion and claims of extra performance from additives (which may/may not be present) instead of just a label B5 and confirming that it is ULSD or not.
And yes - the testing on the Tesco diesel confirmed that the 5% Bio origin oil did not come from rape oil as had been stated but that this 5% of the total was broken down as 30% Palm Oil and 70% Soy Oil. Also I understand the samples were taken of Tesco regular DERV not the Tesco City D (ULSD).
IMHO there should be more plainly marked labels at the pump and signs that can be seen from the highway stating just what is available before you pull in.
All I want to do is get in and out of the pumps a.s.a.p. and be able to identify ;)

Snagger

18th Jul 2008, 16:35

PinkSeriesIII

18th Jul 2008, 23:55

I'll be using my rear tank on Derv and returning its fuel system completely to standard. I'll be fitting a parallel SVO system with an electric pump before the heat exchanger and filter. Only after exiting their respective filters will the fuel systems converge on the selector tap and then run directly through a sinle line to the injection pump.

This way, the mechanical lift pump will not be under additional strain, the electric pump will only need to be activated when running on SVO, both low pressure pumps will be pushing, not sucking, and the filters will be under positive pressure, not negative, so any leaks in any part of the system except the first fuel lines from the tanks to the pumps will result in fuel leaking out, not air being sucked in (making leaks easy to identify and cure, and preventing fuel starvation).

Your planning on using 2 electric pumps, 1 for DERV and 1 for the SVO and the mechanical lift pump is removed/bypassed? If not and your are still using the mechanical lift pump on the "completely to standard" Derv system... what will that pump be doing when SVO is selected? Will it be happy pumping against a closed line?

BTW I read one system where 2 electrical fuel pumps where used svo/derv, and a 2nd heat exchanger and separate fuel line was hooked up to the now redundant mechanical lift pump. The lift pump simply returned the heated fuel to tank as an additional aid to heating the SVO in the tank.

RUXY

19th Jul 2008, 08:44

It doesn't matter much from a technical point whether the biodiesel content is made from soya, rape or palm oil, to my knowledge, as all the damaging fats, acids and water are removed in the trans-estrification and washing processes. It's just a matter of politics and economics.

The point I was making is - the problem you have had seems to be coking up , and that the "Obligated Suppliers" are probably all putting their RTFO target of 5% on DERV. In fact BP stated over 1 year ago that this was to be their next move,so from 15/4/2008 all BP DERV has been B5 (and this is your starting point).
B20 is considered the optimum all seasons European grade (probably for good reason). When car makers were consulted about RTFO many stated 5% max. and are holding here. So IMHO if you are starting at 5% at the pumps - then there is a risk when adding more than an additional 15% veg oil and this is in summer months. Unless you have a more suitable German or French old motor you don't mind taking a risk with :D

Snagger

19th Jul 2008, 10:44

Ruxy, I think you're mixing up the whole SVO/biodiesel thing. We're not talking about biodiesel on this thread, or the mixing of biodiesel with mineral diesel. This topic is about the direct use of SVO.

Pink, I had a good chat at Billing with the Dieselveg guys, and they use the lift pump to suck fuel through the filters as you do. It seems to work for you, and they're happy to warranty the installation on the vehicles they fit out, so it's good enough for me. I'm glad, as it'll save me having to buy and fit an electric pump, wire it up, mount a switch... They said the very same thing as you - the mechanical lift pump would not react well to its output side being closed.

I'll be leaving the whole set up as is for the moment to allow me to run three tanks of diesel (I have clamped the coolant supply to the heat exchanger, so the diesel passes through it without being heated), but once I'm back from the trip, I'll be looking more closely at how to adapt the system.

The two fuel systems will run in parallel thorugh their filters and the heat exchanger in the SVO side, then to the selector valve, the lift pump, a fine gauze in-line filter and the injection pump, just like on the Smartveg system. The tricky bit is the return system. The Smartveg system used solenoid controlled valves, and the return lines have a 20 second delay to allow pruging without cross-tank contamination. I'm not worried about a little diesel being dumped in the SVO tanks (though Dieselveg think it wasteful); I am concerned about SVO being purged from the pump into the diesel tank.

The problem is that I'm using a set of MoD SII/SIII change-over taps (the ones with brass handles on the front of the seat base). The left tap is fine - it just selects between the two SVO tanks, the tap operating both the feed and return line valves (mounted on the same cradle with an operating link between them). The right side tap that selects between the rear diesel tank and front SVO tanks is identical, but I need to look at removing the link between the feed and return valve and fabricating a lever to operate the return valve independently of the feed to allow a delay. Either that, or stump up the £500 odd for the Smartveg system!

RUXY

19th Jul 2008, 11:13

Snagger

19th Jul 2008, 11:30

By the way - military change over valves (when used with diesel) have a reputation for sucking air at the cork washer.
Nothing new about using SVO or PPO or whatever you want to call it, as I stated Farmway tried it 20 years ago and they had good facilities. The problem with forums is the expert twits stating Rudolph Diesel used peanut oil and VLCC's run on crude, the simple fact is I have never seen a Burmeister & Wain fitted in a Land Rover - you can't bunker up and run at set calorific value with heating as required. When I started to Google into what was available about a year ago - I assumed the truth would be somewhere between Top Gear and a touch of white spirit and what the better German kit makers have to say (the odd one having made a purpose built engine for running on Rape Oil).
The pay back figures on your investment to date that you stated a few days ago are not realistic because you have had to tear your engine down & box it up again - also you are unable to determine full damage that can result in future failures.I agree with a lot of what have said there. So far, my SVO experiment has not been economic, but it has only cost me a £60 heat exchanger, a head gasket and a pair of piston rings. But that is because I avoided the initial outlay of hundreds of pounds on a system that I though I could mimic more cheaply with the parts I already had.

You're absolutely right that you can't run a modern diesel on SVO as is - regardless of what the earliest engine ran on, modern engines are designed to run on mineral diesel and nothing else. That's why specialist companies have developped systems to modify the behaviour of SVO to suit the modern diesel engines. I can't say thay they are as reliable as running on SVO, as I haven't ried them, but those who have fitted properly designed kits or DIY systems seem to report a high success rate. At 50p/L less, I'm willing to continue to persue a viable system - I'm not far of it already.

I can't say I have much idea about the calorific values of either fuel, but my own experience has shown me that there is no discernible difference in performance between diesel and SVO, and any reduction in performance would only serve to improve conditions for my gearbox anyway - I don't need the full Tdi performance. An engine is just a means of converting one form of energy to another, and though diesel may have greater calorific value than SVO, if the engine can only convert a certain amount of energy, then perhaps the engine is wasting more energy down the exhaust with diesel than with SVO? It certainly wastes more accoustic energy on diesel - SVO use is invariably smoother and quiter than diesel. I don't know what the reason is, but the extra energy of diesel is not relected in noticeable engine performance.

PinkSeriesIII

21st Jul 2008, 12:48

I am hoping my recent intermittent fuel starvation problems have been solved.

I removed the fuel level sender from the rear tank and found the fuel pick up pipe pointing nearly 90 deg backwards ! this caused air to draw in when tank was not over 3/4 full (I usually keep a full tank) or when at odd angles offroad (engine has been stalling at worst possible times I can tell you!)

This is a non genuine fuel pickup. The pipe can be rotated to different positions with a little force, but I never considered it a problem and it has not been for the last year. I think the introduction of 100% rapeseed with its much thicker viscosity was no match for the 'loose' pick-up pipe - so it was able to move now and again as the fuel sloshed back and forth.

Fixed pipe in place now and yet to get those fuel problems reoccurring. Will increase the vegoil % back up again see what happens as some of the previous problems do not tie up with a dodgy pickup pipe :confused: at least not that I can see.

Snagger

21st Jul 2008, 20:08

Fingers crossed for you, but it sounds like the likely cause - the system in general must be fine if it works with a full tank.

Do you know if the Lucas CAV type filters can provide enough fuel flow for a Tdi? I have two, and they'd be easier to plumb into the redesigned system with their 6mm pipe.

PinkSeriesIII

23rd Jul 2008, 13:23

Do you know if the Lucas CAV type filters can provide enough fuel flow for a Tdi?

No, I do not know. But surely better than the inline paper/gauze 'red' filters the conversion companies push > http://www.dieselveg.com/fuel_filters.htm

I just use dual standard tdi filters as I had one spare. One mounted to bulkhead as per 19j/200tdi's and other mounted in standard 300TDI defender position on o/s wing.

tony109

29th Jul 2008, 22:02

Snagger, Have you de-rated youe engines output in anyway, reduced turbo pressures, etc?
Low cylinder temperatures will cause alot of coking problems. In marine applications, bi passing turbos or reducing turbo boost pressures cause similar effects when running heavy oil. Multispeed engines in general have alternating cylinder temperatures which results in carbon not building up on piston crowns.. As Ive said, only on my constant speed engines have I had the problem of carbon bumping.

Snagger

22nd Aug 2008, 09:28

PinkSeriesIII

22nd Aug 2008, 10:21

No. Apart from fritting Defender manifolds to the Discovery engine (turbo core is Discovery), and having the injection pump rebuilt with HD parts, the engine is entirely standard.

I had one of the coolant line T-pieces split apart on the Alps trip, allowing massive coolant loss. It didn't cause an over heat, but did immobilise the vehicle until I rigged a bypass. I'd rocommend that anyone using such heat exchangers use decent metal T-pieces - these plastic ones aren't up to the job.

I got mine in parallel with the T-pieces . But, the coolant on a defender is using the cabin heater core all the time regardless of the dash heat controls, so it makes sense to put the heat exchanger in series which reduces the amount of joints used by 6 which are all potential failure points. My neighbour just plumbed his in yesterday in series, seeing how he gets on. Parallel is the recommend method for vehicles where the flow to the cabin heater is controlled by value.

Richie_asg1

22nd Aug 2008, 11:49

I'm following this intently, as I still intend getting round to Landy#2's conversion.
I agree that injecting SVO into cooled cylinder walls causes it to condense on them - thus not burn. Has anyone tried a high temperature coolant - with uprated thermostat? Run everything hotter?
I understand efficiency tests run at the major motor manufacturers showed increased efficiency in atomisation at elevated temperatures - mind you it was a destructive test where everything seemed red hot :eek:.

So, better atomisation, increased oxygen, increased environment temperature - am I missing anything ?

I do like the idea of running a dino diesel tank with a high % of cleaning aditives in it - very much like washing the bores after use, and leaving them soaking in a cleaner between uses.

Something else I'm seriously considering, is water injection after the turbo stage as a form of charge cooling. This method is in use already as a BHP enhancer to the racers - I wonder what it's effect would be on veg oil?
The military did try tests and achieved 75% reduction in fuel when running this - so in theory, the engine will run leaner, and burn better - much like the chip pan fireball when you add water I would think.

More minds - more ideas - use what works ;)

tony109

23rd Aug 2008, 04:02

Since youve mentioned water injection, that is what is used to stop carbon build-up problems.. Emulsification is the other method used.. It also reduces NOX to a vertual zero.. EGR is a method now commonly used to drop NOX levels.. It reduces the engines effective efficiency, so it solves one problem but increases another.

Chasesdragons

26th Aug 2008, 10:00

Snagger,
Assuming you are still pursuing SVO use;

Have you uprated injector pressure to cope with thicker fluids?

Have you had the injectors altered in any way to run SVO?

Do you have a temperature gauge installed to check fuel temps - have you installed this POST injectors (return from injectors)?

Do you have a vacuum gauge plumbed in to check if the pumps are labouring in any way (this might be a subtle way to keep an eye on viscosities too)?

I have heard the addition of propanolol (isopropyl alcohol?) to biofuels help with burining, are you familiar with this, have you tried this?

You could install a valve into the return loop. This can decide to loop back to filter OR vent to the SVO tank. This might help you purge the fuel lines quicker when you switch to DERV. DERV going into SVO Tank towards the end, is not going to be a big issue, in fact, it might help having a bit of DERV in the SVO. The valve frequently mentioned is the TECALEMIT VALVE used on old twin-tanked jags. A new one costs apr 35.00. But knowing most in here, you could easily get one from a breakers.

Got to take my hat off to you guys in here. I admire the fact you are confident and CAPABLE enough to act on theories. I have to come up with theories and ideas and then have to PAY somone else to install them for me. At least you arent losing as heavily, financially in your experiments, just a few grey hairs or tufts of same on the floor!

PinkSeriesIII

26th Aug 2008, 14:04

I run with a pair of TECALEMIT solonoid valve as both my tanks are returned.

The other popular valve is the 3 or 6 port pollock valve which is motor driven changeover.

Beware of the so called pollock valves on ebay which are half/quarter the price and are shipped from the USA. They are cheap copies. This is what my neighbour just used and it was dead from box - opened it up to find broken contacts. Had a replacement and that died during the commissioning period.

oxtonvillage

27th Aug 2008, 13:29

Snagger,

I have heard the addition of propanolol (isopropyl alcohol?) to biofuels help with burining, are you familiar with this, have you tried this?

isopropyl alcohol (IPA) is a type of propanol and is used to test the free fatty acid (FFA) content in bio-diesel. It's the FFA that congeals and leads to coking. Methanol is usually the alcohol used in the reaction process to reduce FFA content.

When using SVO, then kerosene (illegal), petrol, white spirit or Cetane Booster (e.g. Redex) are better methods of reducing the viscosity of the SVO and improving the burn.

Having just bought my first Landrover, a 93 Discovery 200 tdi, I was quite tempted by SVO, especially if I could freely mix it with standard deisel. However, I was in ASDA the other day and was quite shocked to see that 3L of vegetable oil (presumably rape seed) was £1.17 a Litre! No doubt I could probably find it cheaper somewhere, but hardly worth the effort!

PinkSeriesIII

2nd Sep 2008, 09:28

I had one of the coolant line T-pieces split apart on the Alps trip, allowing massive coolant loss.

Was it a radial shear?

What source of metal fittings how you used now?

Do you think what I posted about not needing to put the heat exchanger in parallel on a defender is logical in that coolant is permanently flowing though the cabin heater (i.e not valve controlled) and a HE in series would reduce number of joints?

Now that the fuel starvation problems have been solved on my setup I am thinking of revising the layout so it more neater and ruggedised for 4x4 life. Changing it from a parallel to a series FPHE is something I am considering. I think I will leave as it is for the winter as experiment to see how well it fairs, but I am pre-empting that I may need to add lagging to the hot side and possibly include a Facet pump at the rear tank.

Snagger

6th Sep 2008, 18:51

All good stuff guys.

Ultimately, I want to keep everything simple for two reasons - there's little point in trying to reduce fuel costs if the system costs more than the fuel saving, and the more complex a system is, the more likely it is to fail irreparably on a trip.

Water injection or propane/butane induction would be great, but costly and complex, so they're out. I already have manually operated valves for the feed and return lines, and can get round the diesel tank contamination issue simply by removing the cross-link between the feed and return valves and adding an operating rod and handle to the return valve so that I can select the return valve to diesel a short while after switching the feed valve over.

The plastic T sheared where one of the large hoses ended. They have not been replaced, and the coolant system has been repaired with hoses connecting the heater matrix and Hotstart in series, but omitting the heat exchanger. Including the heat exchanger would be in series in the future, just as Pink suggests, as this would also have the benefit of ensuring full coolant flow through the unit. The trouble is it still needs some connectors to match the 5/8" hoses to the 10mm exchanger unions - if I can only find plastic adaptors, I'll be in the same position as before.

For now, the heat exchanger has been left disconnected as I'm running on diesel - the current prices of SVO greatly exceed diesel, so there's little point in upgrading the system to include it and have improved purging - it's cheaper, simper and more reliable to leave it relatively standard. If I can find a source of good sunflower or rape seed WVO, then I'll have another think.

m1ecy

8th Sep 2008, 18:39

Hmm having read this thread from top to bottom, it appears that there is no conclusive answer to the likely damage SVO does.

Sure it will probably coke the engine up at a faster rate - in my case £300 for the vehicle, and about the same in repairs for MOT, I really cant see a situation where I could loose.....

I have tried soya oil at a 30% mix, and the engine runs quieter (lower cetane value), and seems to produce a similar output of power.

The coking shown on Snagger's pistons, in my opinion as a time served vehicle engineer, would not be excessive, certainly the engines I work on these days suffer far more when running on gas! (1/8 - 3/16" build up on the crowns!)

I am quite happy to see a broad range of discussion, and do admit that the general consensus is that Rapeseed oil is the best, but trial and experimentation still have a good place in this sort of thing - especially when the stakes are so low!

Cheers All
Sean

oxtonvillage

8th Sep 2008, 22:19

I have tried soya oil at a 30% mix, and the engine runs quieter (lower cetane value), and seems to produce a similar output of power.

Surely a a lower cetane value would make the engine noisier? In some Australian tests I've seen they use engine noise as an indicator of cetane value.

The coking shown on Snagger's pistons, in my opinion as a time served vehicle engineer, would not be excessive, certainly the engines I work on these days suffer far more when running on gas! (1/8 - 3/16" build up on the crowns!)

Actually this has occurred to me too, only with two stroke motorbikes. When were younger (by 'eck) and we stipped down our crossers, the coking on the piston crown was quite significant - the engine still went OK though.

m1ecy

9th Sep 2008, 06:27

oxtonvillage

9th Sep 2008, 08:43

Erm, no, I dont think so - Higher Cetane values mean a much quicker and vigorous burn - hence a much louder knock - ever tried a squirt of easy start in a diesel engine - very high cetane value!.

I would still question this: http://cat.inist.fr/?aModele=afficheN&cpsidt=2495194

Cetane index is a comparative score with cetane scoring 100, so European diesel spec at 51 is quite a way off pure hexadecane, and it is true that a modern diesel engine could not run on an oil scoring 100% on the cetane index. However, most SVO, especially rapeseed oil has a cetane index similar to, or better than diesel.

oxtonvillage

9th Sep 2008, 11:34

I would still question this: http://cat.inist.fr/?aModele=afficheN&cpsidt=2495194

Cetane index is a comparative score with cetane scoring 100, so European diesel spec at 51 is quite a way off pure hexadecane, and it is true that a modern diesel engine could not run on an oil scoring 100% on the cetane index. However, most SVO, especially rapeseed oil has a cetane index similar to, or better than diesel.

Sorry, meant to say Cetane Number there (http://en.wikipedia.org/wiki/Cetane_number), not Cetane Index (http://en.wikipedia.org/wiki/Cetane_index).

Also, Easy Start has a flash point of -38oC and is made up mainly of acetone, hexane and di-ethyl ether, so certainly will not have a high cetane number.

Snagger

10th Sep 2008, 08:43

Erm, no, I dont think so - Higher Cetane values mean a much quicker and vigorous burn - hence a much louder knock - ever tried a squirt of easy start in a diesel engine - very high cetane value!

Yep, 2 stroke engines are coked up by design, indeed most run better with a bit of coke to help improve the seal on the bore.

An interesting subject, and subjective long term testing with controlled situations will be the only way of confirming the risks involved of running SVO - something I feel most of us will be unable to acheive - too many variables to get meaningful results.That would certainly be the case. I found running on SVO, both with the 12J and the Tdi, to be noticeably quieter and smoother, but with no discernible drop in performance. I had also been led to expect a drop in mpg, but this was eeither not the case or so small as to be un-noticeable.

What has been established by people far more knowledgeable than me is that Soya and Palm oil are "a bad thing". They rapidly gum the engine. It also seems that a heat exchanger is absolutely mandatory on the 12j and 19J, as the Lucas pumps need the fuel to be pre-heated to lowe rthe viscosity, but seem to be optional on the Tdi where the pump tolerates the high viscosity. What is also clear is that while indirect injection engines suffer less coking because of the spray pattern, DI engines will suffer if SVO is used while the block is cold because the cylinder walls act as a heat sink.

The whole point of this thread was not to suggest that SVO can't be used safely, just to point out that it has to be set up right and that just tossing SVO into the main tank is not a good idea. PinkSIII's system mimmicks that of DieselVeg's German produced Smartveg system, and most of those Australians (who seem very experienced at this game) have a similar arrangement.

PinkSeriesIII

10th Sep 2008, 10:29

PinkSIII's system mimmicks that of DieselVeg's German produced Smartveg system, and most of those Australians (who seem very experienced at this game) have a similar arrangement.

Although not the trend of system design here I got to say the USA guys have pretty decent setups that cater for their regions that have proper winter season. Twin tank system with tank heater (water), large water heated filter at the tank. Insulated Pipe in pipe (PIP) heat exchangers are the norm in their setups but they they run them full length from the rear tank/filter to the business end (often run inside the vehicle).
... if only if I could trust long runs of coolant hose ;)

What we need is a water heating system that is totally separate to that of the standard engine cooling system. Either regulated and heated from the hot exhaust or an extra jacket system to the engine block/head or both. If there is a failure which drains the system it not going to effect the engine coolant.

yostumpy

11th Sep 2008, 17:37

why not have an undreseat fuel tank,, with a custom lenght of exhaust running thro it, in place of the centre box.as a heat exchanger, surely alisport could knock something up as a proto.

PinkSeriesIII

11th Sep 2008, 17:48

why not have an undreseat fuel tank,, with a custom lenght of exhaust running thro it, in place of the centre box.as a heat exchanger, surely alisport could knock something up as a proto.

Big safety issue there.
trouble with using the exhaust like to heat fuel so directly is that there is no controlling the heat transfer (exhaust temps can get very high), it could be too great in normal running and carbonise the fuel , imagine if you had an almost empty tank ! it would boil it .... you could cook chips in it for sure!

Spanner110

11th Sep 2008, 18:53

That's the sort of thing I want to find out - will regular fuel additives in reasonable concentrations help keep the innards clean... I like the Millers diesel additive. It can be used in two concentrations - one for regular use, and a double dose for thorough fuel system cleaning. It's also meant to clean the cylinders and pistons a bit and increase the cetane rating and burn efficiency of the fuel. However, if these carbon deposits are a result of the fats in the SVO, then I don't know if the additives will work.
No, you're right about that. Millers doesn't work when the fuel your'e using is SVO, thats because Millers was designed for use with a mineral based fuel. SVO is an organic one.
Did you change the injectors when you started using the biofuel?