Long term WVO users?

[Badfish740]

I am looking to purchase an M35 sometime in the next couple of years and one of the things that has always intrigued me about military trucks is their multifuel engines. I am in the process of trying to learn as much about them as I can, but I'd like to hear from people who have been running their trucks on WVO for long periods of time (ie: years) and what has worked and what hasn't. I am not new to this-I converted my 2003 F-350 Powerstroke (7.3L) to run on WVO via a Biofuels Technologies two tank heated system. I had a 60 gallon toolbox tank in the bed which had a heated pickup that fed fuel to heated manifold where the fuel was then sent to the ports at the rear of each head and into the injectors. Switchover for startup and shutdown (purging) was all handled by the PCM of the system, no user input required. This ensured that the truck was only burning 160° WVO once the engine itself was fully warmed up, and that upon shutdown, the truck would run for 90 seconds to fully flush the lines with diesel. It was a great system and a great truck-the only reason I sold it all was because I needed money for other things once my daughter was born. We drove from New Jersey to Maine and back many times for free, not to mention I commuted 80 miles roundtrip to work each day using only about a pint of diesel for startup and shut down each day.

I never had a problem with my truck in the six years I owned it and the current owner is still using it on his farm, but part of that is because the two tank heated automatic system is foolproof. I never had to worry about remembering to switch over or purge, and I never had to worry about a blend separating in cold weather. That said, I'm curious about the capabilities of these engines. There might be a way to convert the Biofuels system to work with the M35 engine, which I'm looking into, but I'd like to hear from folks who have experimented with blends, line heaters, and other methods to run WVO as fuel and what has worked/not worked long term. Line heaters and preheating devices can be cumbersome to work with, but I'd be willing to try it since this is a unique situation. With my F-350, that was my daily driver-I needed it to start and run every day normally without fail, so I went with the fully automatic system. It's not like I'll be driving the M35 every day, but it will be operating in extremely cold weather (Maine), so I will need a way to ensure trouble free operation even during periods of -30° F temperatures. Looking forward to hearing from folks about what has worked for them with these engines.

 

[Beyond Biodiesel]

I just bought a M756A2 that is equipped with a non-turbo multiful engine. I plan to run it exclusively on my WVO-gasoline blends, which I have been developing and running on a 6.2L DD engine for 6.5 years. I see no reason why the multiful engine will not run just fine on my WVO-gasoline blends.

 

[Avn-Tech]

Badfish740,

why not use waste motor oil?
it only needs to be filtered, then run (less work).
one of the other members here used to run the oil I filtered straight into his Duce.
i plan on mixing mine 70 motor oil, 30 junk fuel.

currently my truck still has the tank of diesel that came with it when I purchased it 3 years ago.
but am getting down to an 1/8 tank and will be putting miles on it this month at wasteland weekend.

if you search old threads, you can see my oil filter setup.

laterrrrrrr
avn-tech

 

[dependable]

I have read of Mercedes 0M-617s getting stuck rings when using 100% WVO with one tank systems or inadequate fuel heaters for the climate they are in. I doubt you would want to run 100% in Jersey winters in any case.

 

[Beyond Biodiesel]

I have read of Mercedes 0M-617s getting stuck rings when using 100% WVO with one tank systems or inadequate fuel heaters for the climate they are in. I doubt you would want to run 100% in Jersey winters in any case.

Well, the OP is talking about running a properly designed, heated, two-tank system, which should work fine on either WVO or WMO, as long as the waste oil is properly filtered and de-watered. WMO does have issues, which have been discussed at length elsewhere.

 

[cranetruck]

You may want to be alert for this sort thing..

 

[Badfish740]

Why not use waste motor oil? It only needs to be filtered, then run (less work). One of the other members here used to run the oil I filtered straight into his Duce. I plan on mixing mine 70 motor oil, 30 junk fuel.

I definitely plan to experiment with it in a multifuel. I never ran it in my Powerstroke two tank system because I had a plentiful supply of WVO and didn't really see the need. Plus WVO and WMO don't play nice if you mix them for some reason. I did run some brand new SAE 30 oil through my two tank system once. Someone gave me two five gallon buckets for it that had never been opened-I dumped it into the heated tank and mixed in a couple gallons of diesel just for good measure-it ran fine, no excessive smoke, etc...

I have read of Mercedes 0M-617s getting stuck rings when using 100% WVO with one tank systems or inadequate fuel heaters for the climate they are in. I doubt you would want to run 100% in Jersey winters in any case.

Any conventional diesel is going to have problems running 100% WVO in an unheated (or inadequately heated) system due to the fact that WVO simply too thick for the injectors to properly atomize at temperatures lower than 160° F. I need to learn more about the injection system in the multifuels and how they handle fuels of varying viscosity-if anyone has a good FAQ or tutorial on the M35 multifuels, please post a link, etc... If a multifuel will handle a WMO/diesel blend with no heat than it should handle WVO without a problem as well.

You may want to be alert for this sort thing...

Polymerization is indeed a nasty problem with a lot of different causes, but I never had an issue in 6 years/100K miles of driving on WVO with my Powerstroke.

 

[gimpyrobb]

Your not looking at apples to apples comparison.

The multifuel is made for a wide rang of fuels. It is not made to use only pump diesel like the mercedes. If you have access to large quantities of wvo, go that route. I have more access to umo so that is what I run. I don't mix the two umo and wvo as they "turd up"(technical term there, I know) and clog the fuel system. I have run 100% oil in the winter, until it got down to 10*, I didn't have starting issues.

These are just results I've found during my use. I am not a chemist and don't care what "the book" says should or shouldn't happen.

 

[Beyond Biodiesel]

I definitely plan to experiment with it in a multifuel... I need to learn more about the injection system in the multifuels and how they handle fuels of varying viscosity-if anyone has a good FAQ or tutorial on the M35 multifuels, please post a link, etc... If a multifuel will handle a WMO/diesel blend with no heat than it should handle WVO without a problem as well.

I agree with you, and that is why I bought a surplus military vehicle with a multifuel engine in it. To learn more about this engine you can start with this thread.
http://www.steelsoldiers.com/showthread.php?112667-What-makes-a-multifuel-a-multifuel

Polymerization is indeed a nasty problem with a lot of different causes, but I never had an issue in 6 years/100K miles of driving on WVO with my Powerstroke.

So-called Polymerization issues with running WVO on diesel engines appears to be the product of blow-by of the WVO fuel into the oil sump, which reacts with the motor oil in the engine, and leaves behind sludge everywhere. I had that problem last year. The solution is to change the motor oil of any diesel engine running WVO-based fuels more frequently than normal. I recommend 3000-4000 mile intervals. I found that I could easily remove the sludge buildup in my engine by simply changing the oil every 100 miles for 4 oil changes, then to go to the above oil change regimen. If you had no trouble with sludge in your powerstroke diesel then you most probably changed your oil frequently. What frequency did you change your motor oil?

 

[Badfish740]

I agree with you, and that is why I bought a surplus military vehicle with a multifuel engine in it. To learn more about this engine you can start with this thread.
http://www.steelsoldiers.com/showthread.php?112667-What-makes-a-multifuel-a-multifuel

I got a lot of great replies and as a result understand these engines a lot better now.

So-called Polymerization issues with running WVO on diesel engines appears to be the product of blow-by of the WVO fuel into the oil sump, which reacts with the motor oil in the engine, and leaves behind sludge everywhere. I had that problem last year. The solution is to change the motor oil of any diesel engine running WVO-based fuels more frequently than normal. I recommend 3000-4000 mile intervals. I found that I could easily remove the sludge buildup in my engine by simply changing the oil every 100 miles for 4 oil changes, then to go to the above oil change regimen. If you had no trouble with sludge in your powerstroke diesel then you most probably changed your oil frequently. What frequency did you change your motor oil?

I actually just stuck to the regular 5000 mile change interval. I had a few oil analyses done by Blackstone all which indicated a healthy engine, and no excessive amounts of byproducts from blow-by in the oil. The engine (7.3L) had 98K on it when I installed the kit and 215K when I sold it to the current owner who is still using it today-the truck will hit 300K miles soon. When I was talking about polymerization though I was referring to it happening in the tank and fuel lines in reference to the picture that cranetruck posted. I've seen that happen in systems where the tank is heated excessively. I still wonder whether heating is necessary or not with the multifuels. Even though the compression is much higher than in a conventional diesel, and cupped pistons provide the swirl effect, the injectors/injector pump in a multifuel still seem fairly conventional. That said, I don't think they are going to atomize cold WVO any better than any other type of fuel that is much too thick. Improperly/not adequately atomized fuel = fuel coating the cylinder walls = blow-by, stuck rings, or worse. Time to do some viscosity tests-WMO vs. WVO at 0°F...

 

[Beyond Biodiesel]

When I was talking about polymerization though I was referring to it happening in the tank and fuel lines in reference to the picture that cranetruck posted. I've seen that happen in systems where the tank is heated excessively.

To me cranetruck's image is classic accumulation of animal fat, and other high melting point esters, which is typical of improperly settled and filtered WVO, no matter how you alter or burn it.

I believe the issue of polymerization is more relevant to motor oil that has been in the crank case too long. It will polymerize, and I have found that polymerized oil melts at 160F (70c) and will not readily dissolve into vegetable oil, but will readily dissolve into hot motor oil.

I still wonder whether heating is necessary or not with the multifuels. Even though the compression is much higher than in a conventional diesel, and cupped pistons provide the swirl effect, the injectors/injector pump in a multifuel still seem fairly conventional. That said, I don't think they are going to atomize cold WVO any better than any other type of fuel that is much too thick. Improperly/not adequately atomized fuel = fuel coating the cylinder walls = blow-by, stuck rings, or worse.

From what I understand about the multifuel engine is it does not atomize fuel. It sprays it onto a cone shaped feature machined into the piston, plus swirling, plus higher compression promotes combustion.

Arguably the multifuel engine was designed by Germans in Germany, I believe, during WWII, and they were looking for an engine that would burn anything, because they did not have reliable sources of fuel. It is my understanding that the US government contracted for the construction of the engine for much the same reasons. That is, on the battle field one cannot always depend upon fuel sources, so engines have to be able to burn anything. Therefore, a multifuel engine should be able to burn WVO without heat, or gasoline; however, I bet it will burn the WVO better (more efficiently) if it is either heated or blended with gasoline at 20%

Time to do some viscosity tests-WMO vs. WVO at 0°F...

I have tested new 10-40 motor oil and new canola oil. At 75F (25c) they have very similar viscocities and specific gravities, and absorb gasoline in a similar way, and respond in similar ways.

 

[Badfish740]

From what I understand about the multifuel engine is it does not atomize fuel. It sprays it onto a cone shaped feature machined into the piston, plus swirling, plus higher compression promotes combustion.

Arguably the multifuel engine was designed by Germans in Germany, I believe, during WWII, and they were looking for an engine that would burn anything, because they did not have reliable sources of fuel. It is my understanding that the US government contracted for the construction of the engine for much the same reasons. That is, on the battle field one cannot always depend upon fuel sources, so engines have to be able to burn anything. Therefore, a multifuel engine should be able to burn WVO without heat, or gasoline; however, I bet it will burn the WVO better (more efficiently) if it is either heated or blended with gasoline at 20%

I have tested new 10-40 motor oil and new canola oil. At 75F (25c) they have very similar viscocities and specific gravities, and absorb gasoline in a similar way, and respond in similar ways.

That makes sense-there was a good discussion going about the swirl effect and what makes a multifuel a multifuel. However, I was doing some searching and found this which concerns me:

http://www.steelsoldiers.com/showthread.php?71978-Injector-tip-coking/page4

The OP ended up getting new injectors (where does one get new injectors for such an old engine?) which fixed the problem. I think I may begin looking into adapting my old Biofuels heated system to work with a mulitfuel-even if I had to switch and purge manually it would be worth it since the truck has such a long warm up time and apparently should be idled for at least a few minutes before shutdown to prevent oil coking in the turbo.

 

[Beyond Biodiesel]

The OP ended up getting new injectors (where does one get new injectors for such an old engine?) which fixed the problem. I think I may begin looking into adapting my old Biofuels heated system to work with a mulitfuel-even if I had to switch and purge manually it would be worth it since the truck has such a long warm up time and apparently should be idled for at least a few minutes before shutdown to prevent oil coking in the turbo.

I think the bottom line is burning oils of any kind in any diesel engine, even a multifuel, is a marginal fuel, and burning marginal fuels in any diesel engine tends to result in coked injectors, rings, valves, etc. So, anything we can do to improve the burn is wise.

The heated two-tank system has been in development for about 10 years, if I recall correctly, and it has proven effective. Blending gasoline has been in development since WWII and also proves effective. So, I will blend, and you will heat your fuel. I just think those who run a heated two-tank system are going to burn a lot less diesel during the warm up period, especially of the multifuel engine, if they started up and shut down on a decent blend.