Bumber Hitch for Aux tank advise needed

[Jeff Bayley]

I need to put a 100 or maybe 125 gallon tank on the back of the bus. It will be custom fabricated out of aluminium and get tall and long so as to not have to be too thick. I'll probabley need to remove the single Reese hitch and put a double or maybe the single can be left and two additonal ones added to each side (I don't know) what the hitch place can weld up yet but to keep it stable I need more than just the center hitch to keep it from tetering (800 pounds). I'll bracket it so I can fold it down if I need to open the bay doors.

Anybody know of a partial component I can use to build around this ? Maybe a bike carrier on an electiric or hydraulic winch would be suitable and I could make the tank more think and less high and use that to let the tank down in case of needing access to the engine.

[Darl-Wilson]

Jeff, it might be helpful to know what type of liquid you will be transporting; flammable, etc. Will you need a certain height for filling the container and where must it drain? Will it be removed when empty? Many years ago I fabricated a device to do something similar to what I think you may need by building a 'triple-hitch' that was bolted to the frame and had 3 2" receivers.

You must have access to the engine compartment and another consideration is that it cannot stress the frame. As Jon aptly pointed out in another post weight on the rear could cause movement in cap and other riveted areas.

I think if you give us more information you will get an assortment of suggestions, probably one of which would suit you needs.

Darl

[Jon Wehrenberg]

Jeff, You already know I am a naysayer so this should not surprise you. I can think of why you are attempting the wrong thing on so many levels.

If you wish to haul a tank full of McDonalds french fry grease (nowhere near the quality of the grease at some Chinese restaurants) you at least need to consider access to the engine. That stuff is dirty and Ken Z's brother in law gave us an excellent seminar at Pahrump on the use of that material and it involved changing fuel filters about every day or 400 to 500 miles. Leave room to open the doors because every day of travel translates into fuel filter changes.

For every 100 gallons of stuff you haul you are dealing with around 700 pounds plus the weight of the tank. In itself that is not good because you are taxing the structure that Prevost limits to 1000 pounds. But hanging it back there means it is not getting heated. It needs to be warm. It will gel. The good news is it is where you can get at it because it is going to get some crud collected in it and that will also need cleaning.

It is already a fact that you can run a lot of different materials through a mechanical diesel engine. You cannot run stuff like that through a DDEC engine. On a mechanical engine if you want to go faster push harder on the pedal. When it starts to misfire, such as going up a hill, switch back to diesel which you need in addition to vegetable oil. When the bus is on the flat, switch back to veggie fuel.

But the DDEC is measuring what is happening during the firing of the engine and the computer adjusts timing and fuel delivered to respond to the electroninc pedal. It is not calibrated for a tank of veggie oil, animal fats, or whatever else you will ladle out of the grease tank.

If you have the optional aux fuel tank that might be the place to start storing your veggie fuel. You can more easily warm it, you can make the complex plumbing enclosed so it will not gel in cold temperatures and your bus will not look like Jed Clampett's. If you succeed in having the first Prevost to run a DDEC engine on Wesson oil post pictures and tell the world.

[Coloradobus]

Jon,
Reading what you just told Jeff, is the 8V a mechanical engine that will allow you run veggie oil it with less headaches than what you described above for the DDEC?

[Jon Wehrenberg]

In Pahrump Ken Z's bro-in-law indicated veggie oil would not work in a DDEC engine. At least that was the understanding I had. I believe that to be true because a mechanical fuel injector meters fuel in a completely different way than the computer controlled fuel solenoids at each cylinder.

His bus had an old mechanical Detroit. I forget which model.

There was a lot to using veggie oil in his bus. First it has a complex system of fuel lines and valves. The bus starts on diesel and only when the veggie oil is warm does he switch to veggie oil. He runs coolant through the veggie oil tank in a heat exchanger. Once warmed up he can switch to veggie oil which has already gone through some filtration and separation before he put it in the bus, and then it goes through more filtration and separation. The stuff is nasty so he changes filters at least after ever day of driving.

His set up required the transfer of less clean veggie oil to a second tank from which the oil was pumped to the engine. Since it has a lower BTU content than diesel it will not perform as well. Going up hills for example he has to switch back to diesel because the veggie oil starts to make the engine misfire.

The guys that the TV stations feature on a slow news day that are driving their VW diesels make it sound like you just pour veggie oil in the tank and off you go. Not true. This fellow had a very complex fuel system piping arrangement, multiple fuel tanks with internal heat exchangers, extra fuel filters and hours of labor collecting this stuff, separating the solids and water from it before he transferred it into the bus, plus the labor and cost to change filters daily. He had a big Racor like the ones we use that had to be serviced daily. I believe he had several thousand invested in his system and except for the tanks I believe he assembled the whole thing himself so you can imagine how involved it was. It took up an entire bay.

What was not answered was the long term impact on such a conversion. As we go from the diesel fuel of the past and begin seeing the low sulfur and the blends with ethanol we see an impact on mileage. That's no surprise because the BTU content of a gallon of diesel compared to veggie oil is much higher. But we are also beginning to hear of issues relating to injector lubrication and problems with seals and gaskets not made to withstand the fuels of today. Our current fuels are not just to burn, but they perform some lubrication functions for our engines as well. I think the jury is out on the long term affect of veggie oil.

[Jon Wehrenberg]

This is a good article that covers the topic fairly well because it discusses what is involved and recognizes the issues to be dealt with

http://journeytoforever.org/biodiesel_svo.html

[Jeff Bayley]

John-

I had seen that link you supplied before, forgot to book mark it and just found your post again. Thanks. I need to read it again. Your points on the electronic measuring of the fuel very well may be true but regarding lubrication, how can you say that the lubrication is less and not better with veg. oil ? Just by rubbing diesel and veg oil betweeen your fingers, can it not be clear the veg oil is much more slippery ? Everything I've read says's it provides better lubrication. The mileage is less that's for sure.

Regarding the rear tank (if I ultimatley decide to advance), that is just a feeder tank for the already refined fuel. The pick up truck I tow would be used for collection and have the filtration system on it with (as you mentioned) a Raycor or similar final filter for good measure on the business end of the engine.

I'm considering taking two Prevost and an 18 wheeler coast to coast to trade shows. If I find out if it will work, the pick up truck and be the chase vehicle to supply all three rigs.

I was thinking of calling Detroit to get a 2nd opinion on the whole computerized mixing, detecting, issue you bring up. I don't fully understand how the WVO would screw that up. Would it not take it's measurements when using the VO and adjust accordingly or are you saying that it is outside the evenolope of adjustment as regards the computer made to operate within the tollerances of diesel ?

[Jon Wehrenberg]

Jeff,

Please call DD and post their response here. If you want to discuss this with the man that did the seminar in Pahrump his address is mrz@pocketmail.com. He is running veggie oil in his 8V71N.

I think you will find DD telling you not to do it. But let us all know the outcome.

[tdelorme]

Are road use taxes not an issue with veg. oil??

[wrongagain]

If I can pipe in here,
If you are going to tow a pickup truck why not use a tank in the bed of the truck and rig some sort of fuel line to the bus.
Or, surrender one of your bays for a tank there.
Other than that, it seems like a lot of engineering for some DOT inspector to red tag.
I'm dying to know how this turns out.

[Jeff Bayley]

Ed-

My plan WAS to put the holding tanks in the bed of the truck. The guru I've been bouncing this off of and consulting with on the engineering insists that it's going to be a huge advantage to get the feeder tank up close and personal to the engine in order for to use the radiator fluid with the customized heat exchanger to bring the oil up to 180 degrees which is required to reduce the viscosity. I'm still unclear if he means to heat up the entire 100 gallon tank (I'm thinking 100 gallons is good) or if the oil pumps out of the 100 gallon tank and in fact heats up in smaller quantities before entering the injectors.

I haven't finished reading the link John sent yet but it's very comprehensive and there is in fact a lot of negative input from that author on using WVO in newer computer controlled diesels. Older diesels like it better evidently and I think an 8V92 would probably drink it up with less concern. I have to finish reading it all. Besides the very long article there are hyper-links throughout the copy that I also need to read.

What I DO know is that at least one guy (with a newer pusher diesel) did this already and did dedicate one bay for the tanks and also the filtration system. You can read about it at http://www.liquidsolarpower.com/ It was a 1997 motor home. I'm learning that the type of pump you have also has a bearing on how compatible the concept works. The guru I've been talking to has converted some semi's. He's in Idaho. I plan on at least stopping to meet him if we're able to go to the rally in South Dakota. As an aside, that's a $1,700 trip for us in fuel (one way) if we terminate in Park City Utah not so far away.

[Jon Wehrenberg]

For the moment lets look at the cost of fuel to travel. And while we are at it lets also look at how that cost compares to other costs associated with ownership of a Prevost. And to make this a little more interesting lets paint a little picture of what is involved in using "free" fuel.

Just for a basis for this example, lets assume a coach gets 7.5 MPG, lets assume diesel costs $4.00 per gallon, and let's assume our coach cost $350,000. We will also assume in our example that the coach is used 20,000 miles per year.

Based on the above our coach is going to use 2666 gallons of fuel. At $4.00 per gallon that is going to be an annual cost of $10,666.

For those of you who are worried about that annual expenditure I suggest you sell your coach today. Because for each year you own the coach you are going to have depreciation that will make that fuel cost look like pocket change. Is there anybody out there who has not had $30,000 in depreciation this year? How much would your earnings have been on the invested capital in the $350,000 coach. At a 5% return you lost $17,500 on top of the depreciation. So you are already in the hole almost $50,000 and you haven't turned a wheel.

But what if you were making payments and paying interest? How much was your interest expense?

And then there are the incidental expenses. Tires and batteries age out, and they cost at least $1000 a year even if you never move the bus. Insurance is $1500 to $2000 a year. If you have Prevost do your service at 10,000 mile intervals I'll guarantee you will not get out the door for less than $1000 each time. Twice is the minimum number of visits for that annual projected mileage so there is another $2000 a year.

You might be able to go a year without any repairs, but if you are typical, before long you will replace a hub seal, or change your air bags, or brake chambers, or wheel bearings, etc. That's what you get for buying a $350,000 bus instead of a new one. You get to pay for repairs the guy with a $1,500,000 coach doesn't have to pay for.

The point is simple. The cost of fuel is a small percentage of the cost of ownership and if it is an issue you are in over your head.

But let's say you have a personal problem enriching some oil rich country half way around the world and you just want to burn good old USA soy bean or corn oil. You can spend $5000 to $10,000 to modify your pride and joy to run on used veggie oil. (If you think normal depreciation is steep, wait until you find out how you have destroyed the value of your bus modifying it and running it on veggie oil.) Be prepared to dedicate your aux. fuel tank or one whole bay or both. You still need diesel to start the bus and to run uphill. Veggie oil will not do it.

You thus add a little more complexity to your bus but that is OK because your primary fuel is cheap....or is it? To get it you need permission from the restaurant that throws it out. Otherwise you are stealing it. In parts of the country restaurants get paid for it. About $.13 a pound, or about $1.00 per gallon because it is a raw material for a lot of products besides being a fuel. So in some areas of the country they love it when you take it away, but in others you are going to pay for it,

So imagine every night before you go to bed you get to spend an hour or more pumping dirty oil through your filtration system so it can refill your tank. You probably need 100 gallons to go 400 miles so you may have to search out and fill from three or more restaurants. When you get done you have to dispose of the water and solids you filtered out. While you are doing that you also need to change the engine fuel filters. That needs to be done every day.

I don't know how others feel but I would pay twice the cost for diesel just so I did not have to grub around in grease tanks trying to salvage enough fryer oil to get me a few more miles down the road. Even at twice the cost diesel fuel is a bargain compared to how much money goes down the toilet annually just because we own a bus.

So if you want to join the "green" crowd I suggest you buy an old "Skoolie", paint it to look like the Partridge Family and convert it to run on veggie oil until the urge passes. I'd rather be sucking on a beer than a greease trap.

[Jeff Bayley]

John-

I think you've pretty much make a closing argument that is irrefutable I'm sorry to admit. Are you related to Jerry Spence or Roy Black ?

If I think about it, half of what was driving me was not the savings of the dough, but the ingenuity of seeing if it could be done.

Maybe I'll work out my frustration on my twin diesel cabin cruiser. It's got older Volvo engines in it which I think are more WVO friendly. The searching for fuel all over different towns isn't a problem since I'm in one place. And the filtration process can be done by my buddy who's house I leave it behind on the canal. It's got two 100 gallon tanks already, so one of them can be filtered WVO and the other one can hold diesel.

Would I be koo koo to work out my internal issues on that platform ?

[JIM CHALOUPKA]

A boat engine works hard all the time. There is no coasting. It is similar to a motor vehicle pulling a long steep grade.

Be careful what you do on the water. There usually isn't any place to go to, or road shoulder to pull onto, and wait for help.

[Petervs]

A boat engine works hard all the time if you run a boat fast. Well, fast is relative. Fast for a big boat with two diesel engines is around 15-20 mph. Nowadays most boaters go 8-10 mph to save gobs of fuel, like 70% less. If you run it that way the engines are not running so hard.

Plus if you have 2 engines, you could run one on WVO and the other on straight diesel. Then you can always get back. Depepnd on where you are boating too. I lazy river is one thing, midst of a hurricane quite another.

Personally, if I were really concerned as a boater, I would just switch to a sailboat.