quote:

surely wvo must also have a higher ability to hold dissolved water just like biodiesel wont it?

*MUCH* higher
and substantially higher than BD

play around with various oils
IME (In My Experience, there's another one for the FUAs page), thin oils like diesel fuel, gasoline, citrus oil do NOT suspend water (at all, as far as I can tell, although if we go down the old microdroplet road again, there may be a droplet size that diesel will suspend, a larger size that BD will suspend, etc)
(citrus oil (d-limonene) seems too thin to hold water droplets of any size, although I haven't confirmed this with a microscope - it settles with such authority that I suspect there is -zero- suspended water in it)(the only reason I mention citrus oil is that it has been used as a diesel fuel additive, it is a natural/renewable fuel, and it will lower both Iodine Value and viscosity substantially)

SVO will hold sizeable (visible) water droplets in suspension

WVO will hold larger droplets than SVO
(although in my tests *washed* WVO loses some suspending ability, especially if washed with a brine, and acts more like SVO)

all this seems to have to do with the oil's
1) viscosity
2) purity (how much other stuff is in it)

plus maybe other variables I can't imagine

but WVO and diesel are 2 totally different animals
consider WVO's ability to hold water as an entirely specific study

New picture and info on this subject

See here

IPs are not the the ONLY parts subject to cavitation damage. More modern diesels often do not have IPs..they have injecors that create the neccesary pressure themselves.

http://photos.thedieselstop.com/showgallery.php?thumb=1...0&sort=1&ppuser=3667

Above is a url (copy and paste) that should provide pics of what cavitation damage looks like in them. If you look closely you will notice that the orifices in a lot of the parts have been "radiused out" and appear almost sandblasted. Contrast the cavitated parts with the new parts alongside them. These are from a 2000 F-350 Power Stroke with 242,000 miles and one owner. He has been running a 50/50 WVO/Diesel mix for the last 4 months / 12,000 miles. They are shot.

Dana
do think the problem was that the blend of dino/WVo was not heated to lower viscosity, or the acid value in WVO? what are accetable levels of acidity in WVO. From different foods cooked or the oil itself being old in age?
the last 200,000 miles would have to wear on them also
;0

Silver

that is worrisome. im running a 2000 f-350 also. 60k miles, running heated for about 5k mi. so i have not IP also right? that is a good question, could it have been the unheated svo that did it?

I think you all may want to read the thread.
Link to TDS

The pics Danna linked are from this thread.

quote:

Originally posted by Silver:
Dana
do think the problem was that the blend of dino/WVo was not heated to lower viscosity, or the acid value in WVO? what are accetable levels of acidity in WVO. From different foods cooked or the oil itself being old in age?
the last 200,000 miles would have to wear on them also
;0

Silver

Water in diesel will also cause cavitation. So it is possible that some cavitation would have occurred in the previous (diesel) miles. The amount of time these injectors were (possibly) exposed to acidity could not possibly have casued this damage. As for your other acidity questions...except in rare situations acidity is removed along with any water if the water is removed via settling.

I just saw a dramatic life-size illustration of the phenomenon of cavitation:
one of these late-night TV guys - Craig something I think - the Scottish guy - had some 'crazy scientist' guy on who conducted the following experiment:
he boiled up some water in a 55 gal drum until it was all steam, then sealed up the bung hole, then put the drum in a cold pool of water to condense the steam
the steam condensed, creating a vacuum in the drum, and the drum dramatically imploded (!)
HUGE lifesize cavitation
you could just see the incredible force that could be generated by a little pocket of steam condensing to water inside an IP and ripping metal off the interior surfaces
pretty exciting

As dramatic as that was it was not cavitation.
Cavitation is not simply implosion. It is the implosion of a microbubble. At those scales wierd things happen. One of the wierdest is that the implosion of this very small bubble can create a temp of well over 1100°C.

well, that's one way to preheat our oil

quote:

Originally posted by danalinscott:
SNIP
Water in diesel will also cause cavitation. So it is possible that some cavitation would have occurred in the previous (diesel) miles. The amount of time these injectors were (possibly) exposed to acidity could not possibly have casued this damage. As for your other acidity questions...except in rare situations acidity is removed along with any water if the water is removed via settling.

Dana,
As you will recall, I am not a chemist, but I believe that if the water were evaporated out, there may still be significant amounts of acidic matter in the UCO. In this case, the acidic matter may be strong enough to cause etching of metals in the fuel system.

Has anyone done any testing of different metals in contact with oils having high FFA levels?

Just a different viewpoint.

quote:

Originally posted by Tony from West Oz (The Wizard of Oz):

quote:

Originally posted by danalinscott:
SNIP Snip... As for your other acidity questions...except in rare situations acidity is removed along with any water if the water is removed via settling.

Dana,
As you will recall, I am not a chemist, but I believe that if the water were evaporated out, ....Just a different viewpoint.

Not sure if your view point is different. Maybe just miss read. Dana said above most acids are removed via settling out the water. Your topic discusses evaporation of the water. two very different things, two very different results when it comes to leaving acids; amongst other things, behind in your veg. fuel.

As to acids causing etching.... sorry I'v seen no imperical data to say yes or no. If I see any info I'll post it. I would think though it would take some long term REALLLL NASTY ACID to damage injectors. Where would one get that kind of acid in the system?

Hello Dana, others
As the owner of a small fleet of tug boats for over 14 years I became very familiar with the damaging effects that cavitation can produce.. On a work boat it generally occours in low pressure areas near the struts and propeler shaft log and on the area above the props between the prop tips and hull... these areas are subject to rapid pressur fluctuations... it seems that it can also be influenced by electrolosis... Which also generally occours in the Cummins 855 engine liners. Could water in the fuel have an effect on cavitation in the injector pump? sure... since water can be vaporized at low temps if there is a lack of pressure... also as temps rise the vaporization occours at even higher pressures... So I guess I learned something...it really is helpfull and necessary to make sure your VO is properly dewatered...
John