Viscosity testing of WVO & blends

Single Tank WVO systems and blending SVO WVO to thin it.

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Postby volumetric_efficiency » Mon Jun 02, 2008 1:02 am

SunWizard wrote: I learned a drawback of the visgage


Ty, looking forward to seeeing more data on viscosities as you progress.

Wouldn't it be more advantageous to use Specific Gravity as an comparative value, since it is much more consistant than viscosity?
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Postby SunWizard » Mon Jun 02, 2008 9:19 am

volumetric_efficiency wrote:Wouldn't it be more advantageous to use Specific Gravity as an comparative value, since it is much more consistant than viscosity?

The viscosity is what matters since it affects the atomization of the fuel, and the ability of the IP and lift pump to pump it.
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95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
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Why viscosity matters.

Postby HoldOnTight » Wed Jun 04, 2008 12:18 pm

Viscosity is a key attribute that affects the particle size of the fuel spray and hence the efficiency of the burn, as SunWizard stated. Less significantly, it also affects the pressure drops across onboard fuel filters, pressure drops along the length of fuel line, and the work a fuel pump needs to do. low viscosity = :D
Late 99 Ford F-250, Designed and installed at home, 30 kMi on VO. WVO temp at solenoid valve is 185-195+F, winter-summer.
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non-linearity of viscosity with temperature

Postby HoldOnTight » Wed Jun 04, 2008 1:45 pm

Sun,
Viscosity changes are generally complex but they don't "misbehave" too wildly unless the viscosity of a component is really high (>1000 SUS). It can be affected by the materials being blended, and whether or not precipitates fall out of the blend. Waxes can come out of solution when blended with diesel, but I believe it may not be significant. Also, long chains of hydrocarbons (invisible polymerized oil) will affect the viscosity some.

Benzene and Toluene have nearly the same viscosity, but different densities. If Benzene and Toluene are each blended with VO, then the resultant viscosity will be different in each blend even if the same ratios are used.

If you take your VO or D2 or the blend in the ratio (80:20) and measure it at 60, 80 deg F, 100 deg F, and then plot the 60, 80 and 100 on graph paper (degF vs SUS), you will find that viscosity does not change linearly with temperature! Some diluents form a more relaxed curve than others, and some oils are linear (like the oil used in your Visgage), but a 40 degF temp change isn't a good indicator of how viscosity changes for VO blends because we are interested in the viscosity at 140 degF and higher. So plotting the curve may be helpful to see how well-behaved viscosity is and extrapolating out to 140 and beyond on the high end is probably a good idea, as is extrapolating to the lower temps likely to be experienced in the winter.

One thing is certain though, if you take 2 components, one with a high viscosity and one with a low viscosity and blend them at 50%, the resultant blended viscosity will be heavily influenced toward the lower component's viscosity and as you've seen, even 20% of a low viscosity component can have a heavy influence... This is probably what we care about most. To reduce viscosity of VO, blenders need to strive for a much lower viscosity diluent that can be used in low amounts relative to the VO.

:roll:
Late 99 Ford F-250, Designed and installed at home, 30 kMi on VO. WVO temp at solenoid valve is 185-195+F, winter-summer.
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WVO/RUG 10% viscosity ?

Postby td2dv » Mon Jun 23, 2008 8:37 am

Next time you get the visgage out could you test a 10% RUG/WVO sample? This OLD 240-D of mine likes a nice long glow on D2, when starting the engine, even warm. On 10% RUG it pop's right off. A pal of mine does pump and injector work http://www.dzldoc.com/ and I asked him to listen to tell if the ignition seemed late/quiet and he thought it was unchanged. Next time I 'fill up' I'm going to draw off a sample to put in the fridge.
Thanks
Benz 240-D
Minneapolis
WVO/RUG (10%) 5 mo/yr
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Postby 240Volvo » Mon Jun 23, 2008 10:44 am

HoldOnTight,

Thanks for the posts. I have a question, though. While you said that the most important information regarding the change in viscosity provided by a blend is for the range of 140F and higher, isn't a good portion of the purpose of blending to reduce potential engine problems related to cold starts? As such, it would seem that the performance at lower temps should be at least as important.
1984 Volvo 240 diesel with a single tank Elsbett conversion: electric fuel filter heater, FPHE, glow plugs, and injectors. Also injector line heaters and block heater, running 20%kero/80%WVO winter blend.
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Postby td2dv » Mon Jun 23, 2008 11:15 am

There is an interesting video on YouTube, I can't find just now, where a guy probes a recently shut down diesel for temperature using several types of thermometer. His point is that the pump and injectors are so hot that the fuel is injected at over 200ºf with the tank at room temp. It looks to me like the main function of the dual tank technique is to for the filter's benefit at below freezing temps.
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WVO/RUG (10%) 5 mo/yr
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Postby John Galt » Mon Jun 23, 2008 12:39 pm

The main function of the dual tank is to have pure diesel available for cold start-up. Once the engine is up to temperature, and especially after it's been 'heat soaking', the fuel for start-up in the injectors and lines is hot enough for complete combustion.

I avoid the need for a 2 tank system by pre-heating the engine and injectors for cold starts. I also mix diesel, naphtha, and kerosene with the clean dry VO to reduce the viscosity and enhance VO combustion.
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Re: vo in you psd

Postby 02powerstroke » Mon Aug 18, 2008 12:01 pm

HoldOnTight wrote:Sun,
Viscosity changes are generally complex but they don't "misbehave" too wildly unless the viscosity of a component is really high (>1000 SUS). It can be affected by the materials being blended, and whether or not precipitates fall out of the blend. Waxes can come out of solution when blended with diesel, but I believe it may not be significant. Also, long chains of hydrocarbons (invisible polymerized oil) will affect the viscosity some.

Benzene and Toluene have nearly the same viscosity, but different densities. If Benzene and Toluene are each blended with VO, then the resultant viscosity will be different in each blend even if the same ratios are used.

If you take your VO or D2 or the blend in the ratio (80:20) and measure it at 60, 80 deg F, 100 deg F, and then plot the 60, 80 and 100 on graph paper (degF vs SUS), you will find that viscosity does not change linearly with temperature! Some diluents form a more relaxed curve than others, and some oils are linear (like the oil used in your Visgage), but a 40 degF temp change isn't a good indicator of how viscosity changes for VO blends because we are interested in the viscosity at 140 degF and higher. So plotting the curve may be helpful to see how well-behaved viscosity is and extrapolating out to 140 and beyond on the high end is probably a good idea, as is extrapolating to the lower temps likely to be experienced in the winter.

One thing is certain though, if you take 2 components, one with a high viscosity and one with a low viscosity and blend them at 50%, the resultant blended viscosity will be heavily influenced toward the lower component's viscosity and as you've seen, even 20% of a low viscosity component can have a heavy influence... This is probably what we care about most. To reduce viscosity of VO, blenders need to strive for a much lower viscosity diluent that can be used in low amounts relative to the VO.

:roll:
hold on tight could you plese contact me about running vo in you psd thanks02powestroke
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Viscosity of blended fuels

Postby mixer » Sun Aug 24, 2008 9:36 am

Hello SunWizard, John and others. I enjoyed reading through your dialog on viscosity of blended fuels. Yes, I too would like to see more viscosity data on blended fuels, because there is not much available at this time. If SunWizard is up for running more tests, how about the following blends?

50/50 WVO/D-2

90/10 WVO/RUG
80/20 WVO/RUG
70/30 WVO/RUG

90/10 WVO/Kerosene (D-1)
80/20 WVO/Kerosene (D-1)
70/30 WVO/Kerosene (D-1)

I spent the weekend tracking down sources for the physical properties of a wide range of fuels. You can find the links at the following URL. By the way, the archive of this Yahoo group is public, so one does not have to join to view the archive.

Physical properties of fuels
http://groups.yahoo.com/group/veggie_fu ... message/60
Advocating blending 5-30% gasoline with WVO in the tank from the pump is far less dangerous than blending a few ounces of two-stroke oil into a can of gasoline for a lawnmower.
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Postby SunWizard » Sun Aug 24, 2008 5:22 pm

To convert SSU to cST:
cSt=.226 x SSU -195/SSU for SSU between 32 - 100
cSt=.220 x SSU -135/SSU for SSU > 100
Here is a chart:
http://www.engineeringtoolbox.com/viscosity-converter-d_413.html

To compute viscosity of any blend:
http://www.gesilicones.com/gesilwizards/blending/fluid2.html

So here are some blends computed using that site (SSU):

Using new canola (125) at 60F:
With winter D2 or Kero (35):
V90: 110
V80: 97 (measured 85)
V70: 85

computed With RUG (30):
V90: 109 (measured 75)
V80: 94 (measured 70)

With worst D2 (45):
V80: 102
V50: 75

V100 heated to 160F= 85 SSU.
100% D2 chilled to 32F= 110 SSU.
Last edited by SunWizard on Mon Aug 25, 2008 9:40 am, edited 3 times in total.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
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Postby zoochy » Mon Aug 25, 2008 2:53 am

Interesting results but not really relevant for this application. The viscosity/fluid blender calculator is intended to “calculate the proper blend ratio for two dimethyl silicone fluids to achieve an intermediate viscosity.”

Mixing hydrocarbons like we are doing and mixing silicon fluids are not even remotely comparable. I’ve searched for an equivalent calculator for hydrocarbons but came up empty handed. Too bad because such a tool would definitely be really handy.

What initially tipped me off was your reported similar viscosities in blending 10% RUG and 10% diesel. Anyone who has tried this knows the end products are nowhere near the same thickness.
91 Toyota Hiace 3L engine w/ a 300W ½” heated fuel line, lift pump, additional 10um fuel filter, and a 2nd diesel tank for starting.
>160,000 km on:
88% canola WVO
11% old gasoline
.6% turpentine
.3% acetone
.1% eye of newt
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Postby SunWizard » Mon Aug 25, 2008 8:34 am

zoochy wrote:What initially tipped me off was your reported similar viscosities in blending 10% RUG and 10% diesel. Anyone who has tried this knows the end products are nowhere near the same thickness.
I agree, that calculator is off with thin solvents since its made for oils. Note that I used winter D2 on my tests, which is as thin as kero (35 SSU), and almost as thin as RUG (30). The above mixes with winter D2 that I tested came out with lower vicosity than that webpage. I did not test RUG with the visgage, so I went out and ran the tests, with interesting results:

with RUG (30):
V90: 75
V80: 70

Which shows the 1st 10% RUG lowered the viscosity a large amount, and a doubling of RUG didn't lower it much more. I will revise the above post.

Another interesting thing, is that putting the RUG in the tester almost broke it, since the lubricity was lowered so much that the plunger wouldn't slide in the barrel. I had to force it with all my strength, and it still took several minutes of hard force to empty the plunger. Normally it slides with no effort at all, even with straight D2 it empties in a fraction of a second. Even in the blended RUG samples, the plunger didn't slide as easy as usual. It would be interesting to see some actual lubricity tests on RUG blends, since this new effect has me concerned. This reminded me how little we really know about these brews we throw in our tanks. Where can I get some eye of newt ? :lol: I hear they are really slippery and that may just be the secret.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
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blend viscosity

Postby mixer » Mon Aug 25, 2008 10:09 am

Hello SunWizard and zoochy, and thank-you both for posting your most interesting findings and thoughts. Yes, a blend calculator would be excellent; however, it does seem that the online calculator that SunWizard posted does not work for our purposes, but maybe it could be altered once we have some blending data to understand what is going on.

Just a note SunWizard, it is my understanding that winter diesel is D-1, not D-2, and it is mostly kerosene, if that is true then it would be helpful for us all to keep our terms straight.

So, SunWizard has given us some raw data to reflect upon. I noticed the () mean your viscosity measurement. Just out of curiosity, do you have access to summer diesel (D-2), because it would be interesting for calibration purposes for you to measure that with your instrument as well. Also, it would be great if you could give us a measured viscosity of new canola (125) at 60F blended with RUG at 70, and 60% new canola, that would fill out our data quite nicely, then we could plot a curve. I think for now just keeping all of your measurements at 60F is fine, and we can extrapolate what might occur at 32F (0c).

SunWizard’s data
New canola (125) at 60F:
With winter D2 or Kero (35):
V80: (measured 85)

With RUG (30):
V90: (measured 75)
V80: (measured 70)

I am definitely surprised that SunWizard had trouble with the plunger on the visgage when RUG was the thinner, or was it when he used straight RUG? Because one would expect that with 70-80% canola oil, it should be pretty slippery. In that case I cannot imagine it is because of a loss of lubricity, but if it is, then we should all reflect upon that as well.
Advocating blending 5-30% gasoline with WVO in the tank from the pump is far less dangerous than blending a few ounces of two-stroke oil into a can of gasoline for a lawnmower.
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Postby coachgeo » Mon Aug 25, 2008 10:23 am

SunWizard wrote:...Another interesting thing, is that putting the RUG in the tester almost broke it, ... I had to force it with all my strength, ....
could the gas be reacting with the material the pluger is made of? Possibly making it sticky?

contact the instraments company and see if they have any thoughts on this.
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