Switching Between Fuel Tanks and Web Sites

[bschwartz]

I would NEVER put a pump in the tank.  If there is a problem..... well you get the picture.
I use a Walbro bellows pump on my Suburban.  It runs about 10 PSI and cycles on demand. 
http://www.fuel-pumps.net/frb51.html

You mention a "complete set of filters..."
If your filter fine enough before you fill your tank, then an on board filter is only to catch dirt and stuff that gets into the tank while filling.  As such, any type of filter should be sufficient.  I'd mount a diesel filter from what ever is convenient to get replacement filters for.  On my listeroid, I use a mercedes housing like this.
http://i34.photobucket.com/albums/d149/tonywestoz/300TD%20Inspection/Picture016.jpg
It uses an easy to change screw on filter.  If your truck needs more flow, then just find a housing from a larger diesel engine.

As your temperature never gets below 65, you may not need much in the way of heating prior to the filter.

Once the engine is up to full operating temperature, as long as the fuel is hot enough before getting to the IP, then the injectors, you are good. 

[WStayton]

Hi Guys!

  I'll second (third?) the reservations to use copper line for any sort of diesel fuel and/or WVO.  It seems like the fuel takes serious exception to the copper line and grows green "fur" all over the inside of the copper line.  AND, it seems like anything with copper in the mix (brass, bronze, . . .) has more, or less, the same problem.

  I have also read of some problems with aluminum lines and diesel fuel - it seems like, if it is used in a high pressure line, especially, it gets work hardened and then splits wide open - guaranteed to ruin your drive to Church on Sunday! <grin>  (Though there MIGHT be some biblical language present!)

Low Gear:

  Why don't you just solve your non-indirect-injection problems by dropping a OM616 2.4 liter four cylinder into your vehicle?  They seem to be commoner than dirt and nearly as cheap - you could just about guarantee that you wouldn't have any fuel problems if you used well filtered WVO in a Mercedes OM616/617 engine.

  Which brings me to another issue - the experience with Mercedes engines seems to be that they will run a long time on WVO or very moderate mixes of WVO and Dino-Diesel - BUT, they don't run nearly as long, without having problems, on WVO as they do on straight Dino-Diesel.  Many of them are running around with over a hundred thousand miles on the clock and they have never had the injectors out of them!  With WVO, the experience seems to be more like half of that (i.e. 50,000 miles) and you need to take out the injectors and clean them and check their flow patterns and the pressure at which they open - and, lots of guys who run WVO in Mercedes OM616/617 advocate using a slightly higher "pop" pressure than is standard - not sure how that applys to your vehicle, but the feeling seems to be that a slightly higher pressure makes the spray pattern better at marginal temperatures - like when you have just started up and switch over to WVO before everything is fully hot - of course this is with the Bosch inline injection pumps which seem to be almost indestructable, so they don't mind a couple hundred more psi - not sure if your single plunger, a la Lucas, pump will be as forgiving.

  As always, YMMV - the forgoing is worth exactly what you paid for it!  <grin>

Regardz,

Wayne Stayton

[LowGear]

Hi Brett,

I would NEVER put a pump in the tank.  If there is a problem...

You need to remember the fuel tanks on this rig hang off the frame rail and are about 2 feet off the floor - see photo.  Not too bad.  I plan to hang the WVO one just behind this one.

Wayne, my brother;

If I weren't occasionally moving eight tons with Izzy up a 35 degree driveway I might consider the Merc engine.  Now if I were converting just about anything else it would be the engine of my choice.  For this unit the upgrade would be the 4BD2TC Isuzu IDI that would bolt right up and give me a good solid 128 HP at 3500 RPM.  But if you hear of another turbo Merc in Washington or Hawaii please let me know cause I'm eyeing dead 4-Runners and Range Rovers (I may not be crazy enough to try a Rover implant but it's a great fantasy cause they be way cool going down the road).

I think I'm covered on the high pressure consideration for the aluminum lines but chances are I'll just strip a second set of lines off another NPR to service the second tank.  I'm still visualizing the line going up the inside of the exhaust on its way to the engine.  I'm also seeing the switching valves to be very close to the tanks and filters.  My photos don't show the two particulate filters and the water catchment gizmo being within a foot of the tank in the photo.

I phoned the welding shop today and a maximum of $200 to put a divider into a long tank making it into two tanks.

Casey

[bschwartz]

Casey,

"I'm also seeing the switching valves to be very close to the tanks and filters."

The further away from the IP the switching valves are, the longer change over/purge times are.
All the fuel in the line from the valve to the IP has to be used up before the engine starts to use the alternate fuel.  Valving near the tank is useful if both tanks use the same type of fuel, and you are only switching sources.

As for Wayne "I have also read of some problems with aluminum lines and diesel fuel - it seems like, if it is used in a high pressure line, especially, it gets work hardened and then splits wide open"

This would be low pressure line, and not subject to those stresses.  Many racers use aluminum fuel line.  Besides, this is for vegetable oil, not diesel. 

[LowGear]

Hi Brett,

It's true that the primary purpose of the second fuel line will be WVO but if things get tight a load of diesel of bio-diesel just might end up in that tank and associated lines.  I think your reminder of low pressure and use time are entirely on my side.  I put darn near 3000 miles on this unit last year.  If you're thinking cost reflectivity then let me advise you that this is a war against the oil cartels.  Wars are not normally cost effective.

I've just re-listed my CL ads seeking a second NPR tank.  I know where one is with everything but it would mean shipping it to Kona.  $160 for a 2' X 2' X 4' box - weight not too important.

Casey

[fuelfarmer]

If you're thinking cost reflectivity then let me advise you that this is a war against the oil cartels.  Wars are not normally cost effective.

What a true statement. That is the best description of alternative energy I have ever heard. But I still think I can beat the odds on cost.

[bschwartz]

My comments were not meant as a cost issue at all.  Simply that if your valves are too far away from your IP, it will take a long time to switch fuels...... ie. you will need to switch off the WVO to diesel  5 miles from your ending destination instead of 1/2 mile.  This may not be a big problem, until you forget to change before getting to your destination.  Then you'd need to idle the truck for 20 minutes to get all of the WVO out of the injection system before shutdown to assure that there is diesel in the lines for the next start.

I am also a strong believer in " this is a war against the oil cartels"

[WStayton]

bschwartz

   A slight nit pick here . . .

  You say:  "  Besides, this is for vegetable oil, not diesel. "

  I think that the work hardening of the aluminum is not a function of what you use to pressureize it.  Be it diesel, WVO, gasoline, water, or just about any liquid (except nitro-glycerin, I suppose! <grin>) So, I don't think it matters that it is going to be for WVO instead of pump diesel.

  Having said that, however, you are right, that it is only a consideration in a high pressure (think injection) lines and really not a consideration here, where the line is for very low pressure fuel transfer.  It was my mistake to insert that issue here!  I am just very sensative to this issue having watched my brother replumb his overhauled to new John Deere 720 diesel and then be surprised when his aluminum injection lines a) Didn't perform quite right - due to their large, relative to steel, expansion, and b) They split wide open bringing things to an immediate halt!!!

Regardz,

Wayne Stayton

[bschwartz]

Wayne, I was kidding about the WVO/diesel thing.

This I why I hate forums/email etc. instead of real conversations.  It would have come across clearly as a joke if you could have heard me instead of reading it....

Oh well.... 

[LowGear]

I expect a certain amount of cross contamination if that is the right word.  Thats why I inquired about the line loop in the schematic vs: the full return to the tank.  I think you see I'm still flirting with using the same filter system for both fuel sources.

Latest fuel in the tank heating flash.  The tanks are steel.  I'm thinking about directing the exhaust across the bottom of the WVO tank.  Too cleaver for my own good?

Casey

[WStayton]

LowGear;

  Umm, err, . . . maybe you should leave an openable/ accessable hatch on the WVO side of things, then you can just fry french-fries in your WVO as you motor along!  <grin>

  Okay, I was/am kidding - but it was an interesting thought! <smile>

Regardz,

Wayne Stayton

[Geno]

Casey, in your climate heating the tank is probably not a major concern. If you get the oil hot before it hits the filters, fuel pump, IP and even hotter before injection you'll probably be fine. This depends on the quality of the oil as well, PHO will need a tank heated to at least 100°f.

Brett has a perfectly good point about purge times when the valves are near the tank instead of the engine bay but if you don't use the truck for a lot of short runs it's not much of a hassle. When I use my Benz it's most often for a 200 mile run to see family or friends. If I use it for picking up stuff in town I just leave it on diesel. I believe a lot of the questions a person has about their conversion depends on their own personal needs.


Thanks, Geno

[LowGear]

Geeezze,

PHO?

I had pho for lunch.  What's this PHO mean?

Casey

Minds; Waste em if you've got em.

[bschwartz]

Partially hydrogenated oil