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Liam
13th September 2008, 12:55 PM
Hi all

Just an update for anyone interested in blending. I have been running my 79 300D on a 30% Kero blend (should be able to drop to 20 or less for summer) for about 2000km. And all is going well. Car starts fine on cold mornings (it is a bit gutless until it warms up, about 3 mins), no excessive smoking smells sweet too! I have been lucky to get a supply of free canola/soybean oil that is changed daily in the restaurant.
Fuel economy exactly 10L/100km
Fuel cost 33c litre
I cold filter my oil through 3 stages.

1. Gravity filter. coles "green bags". These really are a fantastic and cheap initial filter. And i would guess about 5 microns as the stage 2 rated filter bag is still clean after 200l+.

2. Gravity filter 5 micron filter bag sourced from this forum.

3. Electric water pump. 2 micron house water filter.

I then put my 30% kero in 25l drums and pump in my oil. From there i loud the drums into my "mobile filling station" - which is a fancy name for a golf cart with a fruit and veg crate on it and a drill pump!- and into the car. Maybe not the most efficient set up but it works for me and i am refining it all the time.
The total cost for all this including the car is about $1700.
Give it a go!

Cheers
Liam

Combustor
14th September 2008, 02:50 AM
Hello from a newbie who has been lurking on bio and blending forums for many months. Please advise me if blending is not a suitable topic for this forum,but I need advice on a blend for my 1HZ motor in a HZJ78 Cruiser. Climate here
(far north of WA) is in 25c to 45c year round, so viscosity would not seem a problem. First results on a blend of 65% WVO, 25% Jet A1(kero) and 10% ULP were excellent, but after a few tanks the motor has excessive diesel "rattle"on the blend hot or cool, esp. on light load. The motor is fine on diesel, and is quiet on deceleration, suggesting excess timing advance when running the (slightly) thicker blend. Has anyone found this problem, and is it possible I have trouble with my pump advance mechanism using the blend? All advice is welcome.

Regards, Combustor.

neil
14th September 2008, 11:30 AM
Hello from a newbie who has been lurking on bio and blending forums for many months. Please advise me if blending is not a suitable topic for this forum,but I need advice on a blend for my 1HZ motor in a HZJ78 Cruiser. Climate here
(far north of WA) is in 25c to 45c year round, so viscosity would not seem a problem. First results on a blend of 65% WVO, 25% Jet A1(kero) and 10% ULP were excellent, but after a few tanks the motor has excessive diesel "rattle"on the blend hot or cool, esp. on light load. The motor is fine on diesel, and is quiet on deceleration, suggesting excess timing advance when running the (slightly) thicker blend. Has anyone found this problem, and is it possible I have trouble with my pump advance mechanism using the blend? All advice is welcome.

Regards, Combustor.
Combustor.
It might be a better idea to start your own thread with a heading regarding your vehicle type. You might find some members give blending threads a miss.

Liam
14th September 2008, 11:56 AM
Yep. I have been told that there wont be much support for blending here. I suppose it is considered Amateurish. I believe go with what works for you and is within your capabilities.

Cheers
Liam

neil
14th September 2008, 02:18 PM
Hi all

Just an update for anyone interested in blending. I have been running my 79 300D on a 30% Kero blend (should be able to drop to 20 or less for summer) for about 2000km. And all is going well. Car starts fine on cold mornings (it is a bit gutless until it warms up, about 3 mins), no excessive smoking smells sweet too! I have been lucky to get a supply of free canola/soybean oil that is changed daily in the restaurant.
Fuel economy exactly 10L/100km
Fuel cost 33c litre
I cold filter my oil through 3 stages.

1. Gravity filter. coles "green bags". These really are a fantastic and cheap initial filter. And i would guess about 5 microns as the stage 2 rated filter bag is still clean after 200l+.

2. Gravity filter 5 micron filter bag sourced from this forum.

3. Electric water pump. 2 micron house water filter.

I then put my 30% kero in 25l drums and pump in my oil. From there i loud the drums into my "mobile filling station" - which is a fancy name for a golf cart with a fruit and veg crate on it and a drill pump!- and into the car. Maybe not the most efficient set up but it works for me and i am refining it all the time.
The total cost for all this including the car is about $1700.
Give it a go!

Cheers
Liam
Liam hi.
Why have you chosen to use Kero for blending?, Thinner than diesel?.
Have been blending with diesel up to 50/50 in my 1991 direct injection rodeo and even in winter no problems starting.

You will find some good sites re blending in US with merc's and this is a local guy with a newer 300d OZTayls (http://oztayls.blogspot.com/) Not sure if he has got around to full conversion yet but he had been blending for sometime now without problems.
Neil.

Liam
14th September 2008, 03:31 PM
Neil
I use kero because i have a source at $1 a litre. Much cheaper that diesel.

Nicely said Dave. Couldn't agree more. Plus i find it fun to make my own fuel. Blending is easy and safe, no nasty chemicals like Bio production. Plus 100% of my oil goes into the tank. No purging either. I can see a 2 tank system has advantages. But for simplicity you can't go past blending. Still like i said do what works best for you, your car and your driving habits.
I don't go nuts like i have seen on the American sites though.
Can we start a section for blending only?

Liam

Captain Echidna
14th September 2008, 07:23 PM
IMHO, The big problem with blending is that it is too simple, too effective and most importantly, No- one can make any money from it selling conversion parts, pumps, heaters or whatever.
(* Sits back and waits for inevitable flames from the financially motivated. *)


Of course those making money from selling cooking oil wont be unhappy;)
I look forward to seeing how it goes, as there isnt a lot on blending on the forum.

gonzalo
14th September 2008, 09:21 PM
Hello,

I have been bleding since November and honestly, canīt wait to get my hands on the car and covert it.

For sure blending is simple, but I believe it is not the way to go, at least in the long term.

Despite I have never gone above 1:1 ratio even in the hottest weather, I have been unable to get rid of some white smoke and this acrid and nasty smell. I am sure this is the result of not burning the oil properly. What this is doing to the engine internals I donīt want to know.

The fuel filter gets clogged very often, the last one only lasting 2000km.

These 2 problems can be fixed by installing a FPHE, but this only works when the engine is hot.

And then we have the problem of cost. If you are willing to find a regular source of WVO, which is becoming very difficult, carry oil around in dirty sticky and heavy containers, filter it, dewater it, take it back to the car, mess around with funnels, spill part of the oil over the car body and have paper towels always handy, then at least make the most of it and donīt pay for diesel fuel. Let that for people who cannot get their nails dirty.

I installed a two tank system in my previous car and never regretted about it.


But this is only my view.

Cheers
gonzalo

Fitian
14th September 2008, 11:20 PM
I like the idea of blending.

Very easy to do and no need to convert the car or worry about changing over or purging etc...


In my two tanks system...

I drive 5000+ kms every 6 weeks and I use 4 litres of diesel every week for starting up/purging. so 4L X 6weeks = 24 L X $1.67=$40.10 approx.

With this system, I only need to store WVO in my garage. Very safe.

However...

If I am to use a 50% wvo /50% diesel blend, I would use 9 litre/100kms which mean 450 litres of blend. 225 L of diesel X $1.67 = $375.75

I have to store Diesel in my garage to blend before every fill ups/top up

And ...

If I am to use a 85% wvo /15% ULP blend, I would still use 9 litre/100kms which again means 450 litres of blend. 67.5 L of ULP X $1.55 = $104.6

I have to store ULP in my garage to blend before every fill up/top up.

Because we are all different , I like to think everyone is free to go with whatever makes them happy.

Tony From West Oz
15th September 2008, 01:15 AM
Well said Fitian,
The option of blending is available to all who wish to use it.
To overcome the issues of high melting point oils causing filter blockages you could either cold filter tha oils to remove this component, or if hot filtering the oil is your thing, you could add a fuel heater to the fuel line before the fuel filter(s) in your vehicle.
I prefer to blend with Biodiesel and my wife's car runs on a 50% bio/Veggie blend in summer and a 70:30 blend in winter. It has a 10 plate FPHE before the fuel filter, despite having cold filtered oil in the blend. That was how I wanted to use the blend.
This car has been using this fuel for 4 years.

My cars however only use the blend at startup and purging, as they are equipped with 2 tank conversions.

David,
How much do you charge for your oil, should I be passing thru your neck of the woods and need a refill?

Regards,
Tony

gonzalo
15th September 2008, 02:19 AM
This would be far more related to the condition of your engine and its ability to handle veg oil for fuel. If your blending 1:1, I would suggest this problem will very likely get worse when running straight SVO , heated or not. Many people are quick to blame veg for running problems but very few are nearly as quick to take their cars to a mechanic for a going over to make sure the cars are running as they should before they even think of using veg.

Then when you start using SVO, you filter will get clogged in 1000KM.
Blending will have nothing to do with your filters blocking. This is a problem with your filtering and the quality and cleanliness of your oil before you put it in the car. If you are blending with Diesel at 1:1, on SVO you will be using twice as much oil so the contaminants your leaving it it will block the filters in even less KM.

It would be good to review your filtering and drying practices before you go the SVO route because both blending and SVO need clean dry oil to avoid problems such as you are having.

No, they can't.
The emmissions are most likely due to your car not being in the proper running order in the first place. A common problem is the injectors. You should make sure they are as they should be before you use veg in any way.

The only thing a HE would fix would be clogging the filters due to fats. If you are operating your vehicle in hot weather and over decent distances, the filters are easily going to heat up enough to to melt the types of fats that have any place being in your tank in the first place.

Knowing your system is unheated, you should only be putting clear oil with no fats in the tank in the first place. If your not doing this the problems amount to operator error and nothing to do with the practice of blending per se.
If the filters are not blocking due to fats, they must be blocking due to an inordinate amount of particulates in your oil which is again basically operator error and you should revise your oil preparation as suggested above.

Cost??? :confused:
For Blending??
That would be some filters you would need just the same as if you were running a 2 tank system and some Buckets or drums. I get mine free from restaurants and industrial areas.
If a person had to pay for them, the cost could not possibly compare to what people outlay to build a bio processor or to convert their vehicles to 2 tank.

The cost of a litre of fuel may be higher over the long term than bio or SVO but the initial outlay is incomparable. I myself always find it a lot easier to find $50 as one would spend to begin blending than the say $1000 it would cost to do a conversion yourself or set up a decent Bio processor.
One is a no brainier spend that is literally an out of wallet purchase and the other is an investment I have to plan for and consider.

As for finding oil sources and carrying around sticky tins, how is that any different to using veg fuel in any other way or how could you avoid it by going 2 tank or Bio?
I have done them all and that is just the fundamental requirement of veg use.

I am not sure the condition of my engine is an issue. Running on diesel fuel, performance, fuel consumption and emisions are all right. These tend to be good indicators of the fuel system state.
However I wonīt say the engine couldnīt do without new injector nozzles.
As for the filtering, I cold filter my oil to 5 microns before pouring it into the tank. The oil is totally clear, with no fats or clouds whatsoever.
This thing with onboard filters clogging is still beyond me, but I know for sure that WVO can clogg them easily even after 5 micron cold filtering.

Surely the filter gets hot after a long drive, but I can still touch it for several seconds. This is probably not hot enough.

The smoke and smell can be a matter of perception after all. The smoke and acrid smell I complain about may be totally acceptable to another WVO user. This is quite subjective.

And what I meant by finding sources of WVO and carrying it around is that of course you wonīt avoid having to do this with a 2 tank system, but at least you will benefit big time by not having to pay for your fuel.

What I am trying to say is that if you get into this WVO, I believe the best option is to go all the way. Blending is for me putting together the disadvantages of both fuels.

But as Fitian says, here there are options for everybody.

Regards
gonzalo

Liam
15th September 2008, 10:35 AM
For those who do a lot of kms like you Fitan a 2 tank system is likley more cost efficient than blending (unless you have free oil and blend fuel). My partner and myself use the Merc for work and drive it 6 days a week that is still only about 160km a week. so for my relatively short trips blending was the go for me.
No need to get so excited. Each to their own.....
I was hoping that people who blend could share their experiences and blends not argue about it...

Liam

neil
15th September 2008, 10:42 AM
For those who do a lot of kms like you Fitan a 2 tank system is likley more cost efficient than blending (unless you have free oil and blend fuel). My partner and myself use the Merc for work and drive it 6 days a week that is still only about 160km a week. so for my relatively short trips blending was the go for me.
No need to get so excited. Each to their own.....
I was hoping that people who blend could share their experiences and blends not argue about it...

Liam
Would seem I'm stuck in the middle.
I have two cars, an old ute that does not do many k's so I blend, and my
daily drive about 20000km per year. in search of the perfect car to convert to full SVO.
It would seem most members have some kind of experience with blending but eventually continue on to full conversion for reasons above. As you have mentioned "Each to their own".

Fitian
15th September 2008, 12:30 PM
I was hoping that people who blend could share their experiences and blends not argue about it...
Liam


Liam,

In this thread, I can only see that we all shared our blending expereinces. If you are hoping for more info, then you should have searched the forums for "blending" before you start a new thread for nothing.

I do not see any form of arguement in this thread. Could you please point it out.

Liam
15th September 2008, 12:51 PM
Fitan
I didn't think i was starting a thread for nothing. I thought it might be useful to share my current experiences with blending. I have searched extensively and am not after any particular information.
I noticed what i thought to be some irritation in some of the posts.
If i am mistaken i stand corrected.

Liam

neil
15th September 2008, 03:25 PM
I'm glad all our indifference's have now been overcome.
Great to see our experienced users giving there blending experiences.
Back to the thread,
So Liam where do you get that $1.00 a litre Kero.
Neil.

Liam
15th September 2008, 03:46 PM
Neil

I'm not being cagey about my Kero source. But i think his selling it to me is a little dodgy. So he has sworn me to secrecy.
Sorry:D

Nuddy
15th September 2008, 05:47 PM
Neil

I'm not being cagey about my Kero source. But i think his selling it to me is a little dodgy. So he has sworn me to secrecy.
Sorry:D
While we don't endorse anything dodgy, neither are we 'police' here so we respect your oath of secrecy.

$1/litre is about what kero ought to cost anyway if it wasn't for 'free market competition' driving the price up. I can't get it for less that $3.95/litre.

Liam
15th September 2008, 05:54 PM
I got f!@#ing lucky! Not illegal though. Not that kind of dodgy.:) never know how long a source will last though...
I read something about Cleanaway gunwash being recycled thinners. Thats fine but $2.50 a litre seems a bit steep for recycled gear.
Think of all the paint thinners, heater kero and that sort of stuff that gets chucked out every day. *sigh*

Liam

Nuddy
15th September 2008, 05:58 PM
I like the idea of blending.
Very easy to do and no need to convert the car or worry about changing over or purging etc...
In my two tanks system...
I drive 5000+ kms every 6 weeks and I use 4 litres of diesel every week for starting up/purging. so 4L X 6weeks = 24 L X $1.67=$40.10 approx.
With this system, I only need to store WVO in my garage. Very safe.
However...
If I am to use a 50% wvo /50% diesel blend, I would use 9 litre/100kms which mean 450 litres of blend. 225 L of diesel X $1.67 = $375.75
I have to store Diesel in my garage to blend before every fill ups/top up
And ...
If I am to use a 85% wvo /15% ULP blend, I would still use 9 litre/100kms which again means 450 litres of blend. 67.5 L of ULP X $1.55 = $104.6
I have to store ULP in my garage to blend before every fill up/top up.

Because we are all different , I like to think everyone is free to go with whatever makes them happy.
What an excellent summary.
I agree with everything said there.
Blending is also another alternative for the start-up tank.
Some of us have access to biodiesel and of course don't need to look any further for startup/purge fuel. If that's not available then a veg/kero (if you can get cheap kero) blend or a veg/ulp blend may be more economical and better environmentally than buying distillate.

Yeah sure blended fuel is great and as David says, a great way to get started 'on the cheap'.

I was prepared to make the investment in a Fitian conversion and I covered that investment in just a few weeks of 2 tank running. Certainly worth the interest on the money I had to borrow to do it. Now I reckon I am $8000 ahead if I don't count my time and effort.

Liam
15th September 2008, 06:47 PM
98troopy
How much was your 2 tank conversion?

froggo
15th September 2008, 09:46 PM
Hi Liam,

I'm using a two tank system in my troopy but I'm also blending the diesel in my startup [diesel] tank.

I agree with Dave that the amount of unleaded used is improtant. I only add enough to have clean cold starts and clean idles. The 5% ulp also seems to increase performance slightly.

The blend I've used during winter is about 25%wvo, 70% diesel and 5%ulp. This is still reducing the cost of my startup fuel by 25%. No problems at all on this winter blend.

In summer I hope to be using a 50%wvo, 50%diesel and 5%ulp on top of this.

God bless froggo.

Nuddy
16th September 2008, 01:52 AM
98troopy
How much was your 2 tank conversion? For the troopy about $1000 in new parts + Fitians undercharged labour and expertise.
I did the hilux for about $600 in parts and did the labour myself.

tbird650
16th September 2008, 09:49 AM
vaporize and you could feel the engine stutter.

I have a similar "marker". A transparent fuel return line. 1.5 - 2 mins is about the time it takes to see bubbles.

TroopyHZJ75
16th September 2008, 11:33 AM
In summer I hope to be using a 50%wvo, 50%diesel and 5%ulp on top of this.

105% wow thats a big tank you got!! :D

froggo
16th September 2008, 08:36 PM
Hi TroopyHZJ75,

yeh I know, but I'm just:cool:.

God bless froggo.

Geoffwin
19th September 2008, 05:32 PM
At least you know when the tank is full.

There have been many discussions here about blending and to my recollection they were all positive.

I started on blending and still do when the weather is a bit colder, if I do a longer trip it is 100% oil - getting a bit warmer now so things might change :-)

All pretty much horse for courses.

The main factors relate to the startup of the vehicle, blending helps alleviate some of the issues of starting on straight oil but it all depends on your vehicle.

Can only agree with the comments made on filters blocking, you need to look at the process you are using.

In a toyota 1HZ I change the fuel filter each oil change, I found that I could leave to about 7500 but is was not worth the drama of a clogged filter or poor running as it became blocked - far easier just to change it.

One day I might end up at 100% oil, but not in any rush :-)

craigcurtin
2nd October 2008, 02:59 PM
Do any of you guys who are blending run some heating system for the blend ?

I am going to a two tank system (courtesy of Fitian!) but would like to stay with a blend for the startup tank - wondering about the benefits of installing some form of heating to be a bit nicer to the engine on cold starts - i was thinking of Injector line heating

Craig

tbird650
2nd October 2008, 09:18 PM
i was thinking of Injector line heating

I know when my 100w injector line heaters have stopped working because the difference in temp is about 20'C......and if left idling the temp will climb extra 40'C on top.
So what it amounts to is that you can't solely use current for heating.

I think the reason this works as it does and electric heating in the primary fuel circuit doesn't is because:
Each injector line is 25w. The amount of fuel movement in each line is a fraction of what the primary fuel circuit has to deal with. The total primary circuit fuel flow is 500ml per minute (typical Jap rotary IP). Each injector line fuel flow is somewhere in the region of 20ml - 50ml per minute.

If the flow is indeed 25ml. and the watts is 25, then each ml has a watt to heat it. Compare that to 500mls passing through the lift pump primary circuit, and trying to heat it with a 150w GP....no wonder it doesnt make much impact on temps!

Tony From West Oz
3rd October 2008, 01:37 AM
While it will not help cold starting or running, the provision of a heat exchanger immediately before the IP will help warm up the IP before changeover to vegetable oil. When changing back to the start fuel, it will also help heat this fuel up to minimise the likelihood of "thermal shock" when cold fuel enters the IP.
I do not know whether "thermal shock" in relation to cold fuel entering the IP has any basis in fact, especially in Australia, and I don't have the facilities to perform any testing to demonstrate whether this is or is not an issue, but it is something to consider.

A Heat Exchanger in this location will also heat any cold vegetable oil from the filter, before it enters the IP.

Regards,
Tony

Johnnojack
4th October 2008, 12:28 AM
While it will not help cold starting or running, the provision of a heat exchanger immediately before the IP will help warm up the IP before changeover to vegetable oil. When changing back to the start fuel, it will also help heat this fuel up to minimise the likelihood of "thermal shock" when cold fuel enters the IP.
I do not know whether "thermal shock" in relation to cold fuel entering the IP has any basis in fact, especially in Australia, and I don't have the facilities to perform any testing to demonstrate whether this is or is not an issue, but it is something to consider.

A Heat Exchanger in this location will also heat any cold vegetable oil from the filter, before it enters the IP.

Regards,
Tony
Pre heating the IP has got to be useful I guess. However I think one should not change to Vege until the engine is hot or at least up to operating temperature and at that stage the IP is usually hot as well.

As for thermal shock of cold fuel on a hot IP I believe it is a non issue for the following reasons. If you have driven far enough to justify switching to vege (I never switch unless I'm doing 20ks or more) then the whole engine bay is hot and diesel fuel in filters and lines within the engine bay will already be hot. Secondly diesel fuel has such a low specific heat value that on entering the IP it is immediately warmed up by the mass of the IP itself.
Finally if IPs were so prone to damage from thermal shock then it would be disastrous to drive through a puddle of water with a hot engine.

Tony From West Oz
4th October 2008, 03:27 AM
As I said:
While it will not help cold starting or running, the provision of a heat exchanger immediately before the IP will help warm up the IP before changeover to vegetable oil. and

I do not know whether "thermal shock" in relation to cold fuel entering the IP has any basis in fact, especially in Australia,
But I believe that


A Heat Exchanger in this location (immediately before the IP) will also heat any cold vegetable oil from the filter, before it enters the IP.
is a valid statement and should not be dismissed.
This is also promoted by other experienced WVO proponents on this forum.
Regards,
Tony

craigcurtin
5th October 2008, 05:21 AM
thanks for the feedback guys

Tbird - just to clarify - are you seeing a 20degree rise when using your injector line heaters ?

I have been blending for the last two weeks and have noticed a definite difference in how the car is starting compared to when it was on DinoDiesel - ambient temp this AM was 12celsius, running on a blend of 70% WVO, 25% Kero and 5%ULP the car took about 3 seconds to start, previously while there was still Dino in the tank it was almost instantaneous

Dave Jones - would you recommend adding more ULP or more Kero in this example ?

Craig

tbird650
5th October 2008, 09:22 AM
Tbird - just to clarify - are you seeing a 20degree rise when using your injector line heaters

Yep. This is how I've been able to discover that the heater has stopped working. Over 2 years the heaters have stopped 3 times for a variety of different reasons. I've now learnt to check the fuse, relay etc.


definite difference in how the car is starting compared to when it was on DinoDiesel

That is what I find too. Some extra cranking is required and it seems the behaviour is more accute as the temperature drops. I have wondered if there would be any additive that would help this?
For instance with methanol as fuel for racing, the recipe is something like 97% methanol, 2% acetone, 1% castor oil. The acetone in this instance was said to improve cold starting. I haven't noticed any difference when using acetone as an additive for starting with veg (at least none that I could determine).


Heat Exchanger in this location will also heat any cold vegetable oil from the filter, before it enters the IP.

I would go along with that, especially in cooler climates. I once run a 100w nichrome wire wrap on the veg filter. It would get very hot during the time taken to bring the engine up to temp, ready for changeover. It makes a difference in this case because the fuel is stationary. Once changeover occurs, the fuel rushes through the filter at 500ml a minute, then the benefit is minimal.


Finally if IPs were so prone to damage from thermal shock then it would be disastrous to drive through a puddle of water with a hot engine.

I don't buy into the idea of thermal shock either. I've never worried about it and I've never had IP failure (touch wood). I think at least in my case, at purge to dino, fuel runs through a hot valve, then through a hot fuel line before it reaches the IP. Then it's going to mix in with hot fuel in the IP. In addition, if the dino filter is under the bonnet, its' contents will be raised in temperature from heat radiation from the motor and radiator. After all, it has had to sit there stationary while you drive on veg (with a smile on your face!).

neil
5th October 2008, 01:49 PM
Personally I wouldn't touch your blend.
There is this mindset in the veg game that starts have to be instant. My question is why? There is absoloutley no benefit to the engine firing as soon as you touch the key, in fact, the opposite is true.

On performance and race engines, they disable the ignition until the engine cranks sufficiently to get some oil pressure and then they power up the coil and off the thing goes. If you are consistently getting 3 second starts and the car fires up reliably, I would be very happy. This isn't too long to crank the engine and without doubt does it more good than harm.

One must remember that the engine was designed for dino not WVO or blends thereof. Just because it starts instantly on dino does not mean there is anything wrong when it dosen't start exactly the same on a blend. While it takes 3 seconds to fire from cold, I'll bet the hot starts are instant. When the engine is warm/ hot, the oil will flow a lot more freely and the oil pressure will come up very quick. Giving the engine a few seconds to get the oil moving before the stresses of a cold start kick in is only an advantage not a detriment in any way.

You MAY get faster starts with a different blend but it will be at increased expense of petro fuel and may also cause a deteriation of running performance when the engine is hot. ULP is going to be the most effective at making the starts easier but without doubt will also knock the performance off the most effectively. This is another reason I would lnot try to modify the blend for faster starts.

As the weather warms up and your cold starts are warmer, you can start backing off the kero. I run a 5% Ulp blend in summer and it worked very nicely as did a 25% Bio Blend. With the blend you are using, once the weather warms up and your start temp is 20-25, your starts will become more rapid but IMHO, your exactly where you want to be right now. I'd be backing off the kero a bit as the weather gets hotter to maintain the sort of start times your getting now and be satisfied your blends are right on the money.

David any specific ULP you use in the blend. eg. E10 or straight ULP.
Neil

TroyH
5th October 2008, 04:48 PM
I think if you look up the BTU and heating values and work out the temp rise 1W of energy will give oil, You'll plainly see it is completely insignificant for our purposes.

I'm sure the scientists will chime in to correct my lazy maths but I believe that you are looking at about 1 watt per 1.5 o temp rise at that flow on oil. Maybe less.
You have to realise that a Watt is not a unit of energy, it is a unit of the rate of work (energy per unit time). 1W = 1 joule/sec

according to some info from the net, vegetables oils have a specific heat capacity of 1.6 Joules/gram/kelvin. The density of vegetable oils is about 0.92g/mL, so 25mL weighs about 23 grams.

So with a 25W heat source, you have a total of 25J/s*60s= 1500J available for heating.

Q=mCpdT
So 1500 = 23*1.67*dT
Thus dT = 1500/(23*1.67) = 39 degrees

So assuming that your flow is 23g/min of oil, that your injector heating coil is producing 25W of heat, and all of that heat is getting into the oil (which won't be happening), then potentially you could see a 39 degree change in temperature.

TroyH
5th October 2008, 09:59 PM
Over the residence time in the "heat exchanger"

craigcurtin
6th October 2008, 02:33 AM
Dave Jones - thanks for the update and feedback - your first line - (personally i wouldn't touch your blend) had me going !! I thought i had copied exactly what you were doing from earlier posts - then i got what you meant - my blend was fine ! Thanks !.

Troy, thanks for the clarification on what you have said - i think the potential for a better start is probably even better than what you have indicated as you have to also take into account the fact that you have a length of Injector line (say 300mm) which you would heat for a couple of minutes prior to turning on - so that first rush of fuel should be nice and warm.

I was also going to ask for clarification on another point - Dave Jones - mentioned that even if we heat the oil, the Injector will suck that heat right out into the engine block - i would have thought the amount of heat wasted to the block would be minimal and would be to do with the amount of time resident in the injector prior to hitting the swirl chamber (i.e. IDI not DI engines) ? Also theoretically the injector line heater should be actually adding some heat to the injectors also i would have thought. (again assuming i turn on for a couple of minutes prior to starting)

Craig

TroyH
6th October 2008, 12:38 PM
Think about one thing, when you think about the injector "sucking" heat out of the oil.

The only way the heat can flow from the oil to the injector, is if the oil is warmer than the injector. Now, if you don't heat the oil at all, the oil is probably at the same temperature of the injector already (assuming you've been stopped for some time). If you do heat the oil, then the temperature at which the injector and the oil will come into equilibrium, will be somewhere between the original temperature of the oil, and the injector. So it will be warmer than if not heated.

To what extent it is warmer, will depend on a lot of variables. It has nothing to do with how you are heating the oil, only the temperature to which it is heated, and the flowrate.
Certainly the injector will cool the oil, but I imagine the injector would also be one of the first components heated by the combustion that is occurring?

Johnnojack
6th October 2008, 10:42 PM
Think about one thing, when you think about the injector "sucking" heat out of the oil.

The only way the heat can flow from the oil to the injector, is if the oil is warmer than the injector. Now, if you don't heat the oil at all, the oil is probably at the same temperature of the injector already (assuming you've been stopped for some time). If you do heat the oil, then the temperature at which the injector and the oil will come into equilibrium, will be somewhere between the original temperature of the oil, and the injector. So it will be warmer than if not heated.

To what extent it is warmer, will depend on a lot of variables. It has nothing to do with how you are heating the oil, only the temperature to which it is heated, and the flowrate.
Certainly the injector will cool the oil, but I imagine the injector would also be one of the first components heated by the combustion that is occurring?

I did some calculations and confirmed Dave Jones quoted flow rates ( I got 30ml per minute) that equates to 4 /100ths of a ml per injection. Not a lot of oil. Take an injector, have a look at it, feel the weight of it. When it is cold and in a cold engine head that tiny flow of even very hot oil is going to make bugger all difference to it. While injector heaters may help I still think the only way to heat up injectors is by heating up the head first, ie running the engine up to operating temp. Why do we need hot injectors? To ensure good spray patterns and therefore combustion.

TroyH
6th October 2008, 11:53 PM
Can't be any colder than without the injecter heaters tho, can it. :P

I couldn't quantify how much the injector would cool the oil, without knowing a bunch of factors. Thats why I was simply discussing the potential for heating the oil.

Nuddy
7th October 2008, 02:45 PM
Posted in another thread but this is about blending:
"Got on a boat mid-day Friday, home monday afternoon.
Friday morning on 75/25 blend the patrol would not start on the starter motor.
Rolled downhill and it started immediately I released the clutch and ran perfectly from cold. However hill starting only from cold is no acceptable so I am back to 50/50 for now. Left from Friday mid-day to Monday night and then started first kick on 50/50. I agree with David (written elsewhere) that it is better for the engine to crank for 3 seconds or so from cold rather than first kick with all the lube oil drained off and no pressure. I am thinking that I will in future crank the engine for 3 secs before cycling the glow plugs.
I will stick with 50/50 till I can get the 2 tank operating."

I'm still to phobic about petrol in the IP to run any petrol in my blend. Otherwise I would try 95% WVO and 5% petrol.

The patrol runs perfectly from cold on 75% WVO/25% distillate, it's only the starting from cold that is a problem. My troopy was quite happy on 100% WVO from 20oC engine temp but wouldn't start on it.
I believe that just minutes after starting the injector tips and thus the fuel injected are over 100oC.
As soon as I have the 2 tank set up I will experiment with how long I need to run on distillate before switching to WVO and get good clean running.

Jeffrey S. Brooks
12th November 2011, 01:49 AM
I know when my 100w injector line heaters have stopped working because the difference in temp is about 20'C......and if left idling the temp will climb extra 40'C on top.
So what it amounts to is that you can't solely use current for heating.

I think the reason this works as it does and electric heating in the primary fuel circuit doesn't is because:
Each injector line is 25w. The amount of fuel movement in each line is a fraction of what the primary fuel circuit has to deal with. The total primary circuit fuel flow is 500ml per minute (typical Jap rotary IP). Each injector line fuel flow is somewhere in the region of 20ml - 50ml per minute.

If the flow is indeed 25ml. and the watts is 25, then each ml has a watt to heat it. Compare that to 500mls passing through the lift pump primary circuit, and trying to heat it with a 150w GP....no wonder it doesnt make much impact on temps!So, we now get to the bottom of why your engine is experiencing vapour-lock on ULP blends. I would think a ULP blend would not need injector line heaters, so you could put in a switch to shut them off if you wanted to run ULP-based blends

tbird650
12th November 2011, 04:28 PM
Um, no, wrong assumption JSB. I haven't used those heaters since '09. They were for use with unblended svo which I quit at the time as well.
Blending ever since though. I'd also agree no heat is necessary or desirable with blends, especially so with ones with a ULP component.

Jeffrey S. Brooks
13th November 2011, 01:57 AM
Um, no, wrong assumption JSB. I haven't used those heaters since '09. They were for use with unblended svo which I quit at the time as well.
Blending ever since though. I'd also agree no heat is necessary or desirable with blends, especially so with ones with a ULP component.Then, I cannot understand where your heat is coming from to cause vapour-lock on your fuel system with blends containing ULP. There should not be significant heat in the engine compartment for returning fuel blend to cause vapour-lock of a ULP-based fuel blend, unless there is a significant heat source, such as a heat exchanger or fuel line heater.

tbird650
14th November 2011, 01:21 PM
There could be a number of possibilities.
First thing about the Hiace is the engine compartment is very, very cramped and there's heatproof insulation preventing heat from soaking into the interior of the van itself. Any heat that's in the engine compartment can't rise and is to a certain extent trapped. I reason that after shutdown, the fuel in the injectors and injector lines will quickly rise to the prevailing engine temp. If there's any volatile component in the blend it may aerate. If this is the case it would explain the hot restart problem. It's nothing that some extra cranking won't fix but the starter must be getting extra workout over time.

I suppose another possible is your petrol could have less volatile additives. That may be more your field?

The issue was more pronounced if the vehicle does more than... say 30mins running and moreso when the ambient temps are higher.

In my case at least, what I can say is that blends without petrol hot re-start significantly better. What I'm doing now is working from the opposite end of the scale and adding progressively more ULP, but starting from scratch. So far I haven't noticed any deterioration with a 1.5% petrol blend. Next I'll try 2 or 2.5%. That'll be probably a couple of weeks away.

I notice you're keen on the experimenting so I was thinking that an experiment on the stabilty of a blend could be done by progressively adding heat and monitoring the boiling or bubbling threshold temps. It would need a bit of careful consideration as to how to capture the data accurately. Just a thought.

Captaincademan
14th November 2011, 01:32 PM
I am still amazed that you are getting vapour locks on the pressure side of the IP. I would have thought that the ambient pressure of the fluid would prevent any vapours from forming as they left solution. How many PSI does your IP operate at in the fuel lines?

I know that vapour locks occur in a petrol fuel injected motor on occasions (even then not often on the pressure side of the pump - thats one reason that fuel pumps are located in the fuel tank), but I thought the operating pressures were well south of that of a modern Diesel engine.

A few numbers here to think about. How hot does it really get in the engine bay? I would have thought that it wouldn't climb over 150 on the exhaust side? At the worst case you would be lucky to get 150 degrees on the intake side, but for the sake of the exercise lets assume so. (unless anyone has some numbers they can add). So the question is at what temperature do you need to raise the fuel (blend) to in order to boil it at the ambient pressure inside the fuel lines? Pressure has a dramatic effect on boiling point. At the PSI that should exist inside your fuel lines, I doubt it would boil at 150 degrees.

Has anyone got any data to add to this?

tbird650
14th November 2011, 08:18 PM
Of course we are speculating that the issue is indeed vapour lock. The extra cranking would appear to fit the symptoms though.

One more thing that happened one time, was I had some thinners which was only marked "thinners mix". I made a small batch of fuel using this along with other distillates. This was particularly hard hot starting but the exact composition will remain a mystery.

Another time I'd overdone the thinners was with toluene, acetone and may be one other (I think it was). On this occasion the van ran quite well for an hour or so.
Then after a slightly difficult start, while driving home, streams and streams of bubbles could be seen in the return line. I was struggling to keep up with traffic!
I should note that this was at a time when I had an inboard fuel tank so wasn't having the benefit of any cooling of fuel lines. I believe the fuel was getting
hotter and hotter because hot fuel was returning to tank, then upon being fed back to the IP, became hotter still. Kinda like a runaway effect.

Just puzzling over the possibilities, after a motor is shut down, I wonder if fuel that's in the injector lines can escape after a while through the injector return lines.
These are the row of banjos on the injectors themselves that re-route the diesel that's left over from the injection process. On my Toyota, these are plumbed to the return
banjo on the IP, then onward back to the tank. If fuel can slowly bleed back through this return line rail, it could explain how air could be in the injector line. It could effectively be displacing the fuel.

Tony From West Oz
14th November 2011, 11:04 PM
The injector return lines return to near atmospheric pressure when the engine is off.
Following each injection, the injection line pressure is released into the return line by the injection element, regardless whether it is an inline or rotary injection pump.
This occurs because the metering of fuel delivery is controlled by a "spill port", which opens when the required amount of fuel has been injected.
1948 shows the operation of the spill port.

When the injector pressure is reduced, it has a valve which opens to release pressure, to prevent dribbling.

When the engine is not running, the pressure in all, or all except one (possibly being at the start of injection?), injection lines will be at atmospheric pressure, due to the action of these valves.

At atmospheric pressures and temperatures of >90°C, petrol will easily boil out of the blend in the injector lines, raising the pressure a little and pushing the fuel into the return lines, severely affecting hot starting of the engine. This does take time to occur, so hot starts after a short stop may be easier than after a longer stop.

During cranking, the starting volume of fuel is pumped into the injector lines, but until the vapours are condensed as the pressure rises, the injector cannot reach injector opening pressure. When the injector lines are full of fuel (blend) the injection pressures are reached and the engine will start, but may have a rough start due to different heating of some injector lines having boiled more petrol out of the blend than other lines, thus needing more fuel to be pumped to fill that injector line before the pressure rises enough for that injector to open.

As the engine cools, the condensing of the petrol will reduce the pressures in the injector lines and suck the blend back into the injector lines, either from the IP or from the injector return lines, allowing relatively easy starts.


I hope this helps explain the pressures involved and why it is an issue with hot starts but not cold starts.

Regards,
Tony

Jeffrey S. Brooks
15th November 2011, 03:04 AM
When the engine is not running, the pressure in all, or all except one (possibly being at the start of injection?), injection lines will be at atmospheric pressure, due to the action of these valves.

At atmospheric pressures and temperatures of >90°C, petrol will easily boil out of the blend in the injector lines, raising the pressure a little and pushing the fuel into the return lines, severely affecting hot starting of the engine. This does take time to occur, so hot starts after a short stop may be easier than after a longer stop. Regards,
TonyI agree with all, but this part of Tony's description of the injection process as it applies to ULP-based blends. I have a rotary IP and I have worked on my injectors and injector pump numerous times, and each time I crack open the injector pipes significant pressure is released, so I doubt that the pressure drops off due to time within the short time of parking a vehicle, unless you have leaky injector pipes.

Tbrid, while you and I have different diesel engines, it seems like there are significant similarities between them. For instance a common problem for the 6.2L Detroit Diesel is a hot restart problem, which has nothing to do with burning alternative diesel fuels. In that case the hot restart problem is a sign the IP is beginning to go. The short term solution is to open the bonnet and dump cold water on the IP. The solution is to replace the IP. So, maybe in your case this is true, but only observed with ULP blends, because ULP in the blend exacerbates the pending hot restart problem.

However, if I recall correctly, you had been measuring the temp of your return line and you had observed temps as high as 60C. Now, I get that you have a cramped, and well insulated engine compartment, but so do I in my 1983 Chevy G-20 van. However, I do not notice boiling returning fuel. So, perhaps there is something different about your fuel line, or the return line, such as: they are in close contact with the engine block, and/or the exhaust pipes and/or manifold?

Your experiments of slowly raising the percentage of ULP in your blend is a good one, and I look forward to reading your reports.

On your hypothesis that there are lighter fractions in the US variety of ULP, verses the Aussie version, I am not sure that would apply; however, there might well be more alcohol in USA ULP, because we have a mandate of 10% in all of our ULP. However, I would not think that the presence of ethanol would substantially raise the boiling point of our ULP, if anything it might lower it.

tbird650
15th November 2011, 10:25 AM
I hope this helps explain the pressures involved and why it is an issue with hot starts but not cold starts.

Excellent, well reasoned explanation there Tony.
This summarizes the situation quite well.
And, yes the dribble issue would be why pressure needs relieving. It stands to reason.

As mentioned earlier, I'm going on a step-by-step trial to determine where the threshold amount of ULP% is for my vehicle.
I reckon each make and model could behave quite differently. JSB's Chevy appears to get away with a huge amount of blend ratio.

I take my hat off to JSB for taking the time and effort to report findings that might benefit us all in the blending community.
His work pushes the boundaries and tests assumptions. This forum is about helping each other! Thanks

smithw
15th November 2011, 12:47 PM
Hi T Bird
toyotas also get had to start when hot if they have a cracked head, might be worth trying a tank of dino and see if the problem is still there.

tbird650
15th November 2011, 06:46 PM
Hi smithw
Thanks for the thought. The problem isnt there now.
My current blend has only 1.5% ULP and the hot re-starting is quite acceptable.
Cold starts fire up after perhaps 2 compressions, virtually instant.
Hot restarts would add maybe 1 or 2 extra compression strokes before firing.

Re the ULP testing. I'm looking to find the max amount of ULP% that still gives a good hot re-start.
I'll keep upping the % till I get unacceptable deterioration and then back off the amount to the "sweet spot"

Tony From West Oz
15th November 2011, 10:44 PM
Tbird650,
My Mercedes 300D is much quicker at starting when warm or hot. It is on 100% veggie, so ULP is not an issue at all. I believe it fires on the first compression when warm or hot and on the second or third compression, after glowing a suitable time for the ambient temperature, for cold starting.

For a diesel engine in good condition, I believe that this should be the case.

For a diesel engine with poor compression, cold starting is harder because less heat of compression is generated during cranking. the same engine, hot, has the advantage of a higher initial air temperature in the cylinder before compression, resulting in adequate air temperature at injection, for the injected fuel to ignite.

I hope this helps fill some gaps,
Tony