Auxiliary Cell Design

[madmike2]

J2M, keep in mind that the Tanji doesn't flow "quickly". In fact, I usually wait until the main tank is down to 3/4 to 5/8 before opening the valve from the Tanji. The system then holds that level, what seems like, forever. It isn't going to, nor does it need to, transfer immediately like a pump transferred system might.

Not hard to do - just a bit freaky to be drilling a hole in your main tank. Ain't no goin' back once you're there.

Amen, brother Hal!

 

[Capt. Bob]

I don't even want/need an AUX tank and this thread has my interest. :blink:

Same here.

I know this has been done before but for some reason it now has peaked my interest

 

[Capt. Bob]

06 tank penetration - courtesy of Tom Melchild Clicky
Sampson prototype install - Clicky

Not hard to do - just a bit freaky to be drilling a hole in your main tank. Ain't no goin' back once you're there.

Thanks KD,

I was wondering where the fitting would go, though logic would dictate underneath.

 

[Joe2Lmaker]

In fact, I usually wait until the main tank is down to 3/4 to 5/8 before opening the valve from the Tanji. The system then holds that level, what seems like, forever. It isn't going to, nor does it need to, transfer immediately like a pump transferred system might.

I was reading here that air in the line can be a problem.

What can I do to make sure I don't end up with that problem?

Is anyone using a primer bulb like this?

 

[James]

In fact, I usually wait until the main tank is down to 3/4 to 5/8 before opening the valve from the Tanji. The system then holds that level, what seems like, forever. It isn't going to, nor does it need to, transfer immediately like a pump transferred system might.

I was reading here that air in the line can be a problem.

What can I do to make sure I don't end up with that problem?

Is anyone using a primer bulb like this?

I don't, & don't remember seeing anyone else who has. I would think w/a gravity system, if your fuel lines are run w/out any odd humps or loops air would either bubble up into the aux. , or into the main tank when you opened the valve between the two. The way you run the fuel line can be key to making it work properly.

 

[kaitsdad]

In fact, I usually wait until the main tank is down to 3/4 to 5/8 before opening the valve from the Tanji. The system then holds that level, what seems like, forever. It isn't going to, nor does it need to, transfer immediately like a pump transferred system might.

I was reading here that air in the line can be a problem.

What can I do to make sure I don't end up with that problem?

Is anyone using a primer bulb like this?

:hyper:

Well, there's always this -

sorry - don't mean to start a tangent here - but I just couldn't resist -



The primer bulb would give you the ability to get the fuel moving and clear an air trap - however, it would have to be accessible. In gravity feed, the differential in elevations of the fuel egress/ingress path in tandem with the fuel levels in both tanks (pressure differentials) can have an effect on the transfer. These levels will dynamically change not only with the fuel transfer, but the attitude of the bike.

 

[dcarver]

The primer bulb would give you the ability to get the fuel moving and clear an air trap - however, it would have to be accessible. In gravity feed, the differential in elevations of the fuel egress/ingress path in tandem with the fuel levels in both tanks (pressure differentials) can have an effect on the transfer. These levels will dynamically change not only with the fuel transfer, but the attitude of the bike.

Paging RenoJohn, Reno, you there? [SIZE=8pt] RJ had a great post about riding UP a hill with gravity feed flowing... and draining the main tank! LOL.[/SIZE]

Get this thing built, and I bet you'll have lots of orders. I want one.

 

[Joe2Lmaker]

Paging RenoJohn, Reno, you there? [SIZE=8pt] RJ had a great post about riding UP a hill with gravity feed flowing... and draining the main tank! LOL.[/SIZE]

I seem to remember reading that the same thing happened to Ignacio on the way up Pike's Peak

O.K. next question.

I'm planning on calling Cole-Parmer for part numbers for suitable non-spill quick disconnect couplings

What are you guys/gals using?

Something like this would be nice:

 

[madmike2]

Paging RenoJohn, Reno, you there? [SIZE=8pt] RJ had a great post about riding UP a hill with gravity feed flowing... and draining the main tank! LOL.[/SIZE]
Get this thing built, and I bet you'll have lots of orders. I want one.

Uhm...er...theoretically...so I've heard...on a hot day, if the rider were to let the main tank get to 1/4, and if the vent was slightly blocked, the pressure in the main tank might be able to force 2 gallons from the auxiliary tank. However, that is just a rumor as there are no pictures or witnesses. :blink:

Not to digress from the intent of this thread: designing an auxiliary tank, there is a learning curve to using the gravity feed auxiliary tank. If one opens the transfer valve while the main tank is full then the fuel level is above the auxiliary tank so the fuel is going to transfer to the lower level....as RenoJohn stated in his post (going uphill for an extended time effectively raised the fuel level in the front/main tank). That's why my combination has taught me to let the main tank get to 3/4 (on level ground) before opening the transfer valve.

As kaitsdad pointed out and I quoted above:

There ain't no goin' back!

Even commuting and running errands, the ability to ride 375-400 miles before having to stop for gas is a plus. Traveling? Torrey UT to Ely NV...at speed and non-stop: I love it!
J2M, keep up the good work and you might want to consider getting a Gen I test mule so you could design the same tank with a different bottom plate to fit the older style. I think there could be quite a demand for these.

 

[twistedcricket]

What is the downside to a small powered pump to keep the fuel flow going? Not only going uphill, but if you're on twisty roads, fuel sloshing from side to side....

Also, with the talk about options to mount lights, antenna sticks, etc; what if you made the top plate over-sized by 2" around the sides and rear of the tank?

 

[madmike2]

Something like this would be nice:

I got my fittings with the fuel cell, but they were purchased from this place: https://www.tempoproducts.com

Part numbers:

Tempco brand, Part # 220060, Model # 461CRC (Chrysler/Force) and

Tempco brand, Part # 220080, Model # 464CRC (Chrysler/Force)

I got my bulkhead fitting here: https://www.sampson-sporttouring.com/hardware.html

A back-flow valve would protect a gravity feed system from over-flowing the auxiliary tank. I don't know if they offer one but someone must know a source for a one-way check valve that doesn't need pressure in the "flow" direction.

 

[Joe2Lmaker]

The next plate is ready to be bent.

I had no idea I was going to get such an education in sheet metal. Holy crap! Bend allowance, K-factor, Y-factor, ...

If you cut angles on a piece before you bend it what do you get? A radius is what you get (in the corner). :dribble:

Anyway, if you remember, I was happy with the way this plate looked:

This is what I came up with for the front and sides (plate 2):

(the lighter colored piece is what I have now)

And a view from the bottom:

If this works, all I have left are the two easiest pieces! :yahoo:

 

[Warchild]

I'm hoping some experienced LD guys are interested in this because I have a question.

O.K. Here's the question: It looks to me that if the bottom of the auxiliary tank were at this level (my design puts it here) it would be high enough for a gravity feed system. I believe the bulkhead would be below the red line.

Apologies for not picking up on this thread before now.

Joe, your cell placement will transfer fuel... eventually. But it will be at an interminably slow rate. It will be agony to transfer the contents.

It would be advisable (assuming it's feasible) to increase the distance between the bottom of the stock tank (where you will install your bulkhead fitting), and the bottom of the aux cell (depicted by your red line above). As it sits right now, you will likely have insufficient "head pressure" to afford a reasonable transfer rate. My gravity-fed cell sits about 2.5" higher than yours, and it still takes me a good amount of time to transfer.

That having been said... if you are absolutely dead set against raising the floor of your aux cell, you can always go the electric pump route. Or live with the slow transfer rate.... as long as you're not "out-pacing" you fuel flow rate (i.e. running at a high enough speed to where you are burning fuel before it can be replaced by the slow transfer rate), then it's more of an irritation than anything else.

Happily, the latter usually only occurs at the more "wild" Endurance events such as BLISTER, or White Pine Fever.

 

[weekend rider]

Have you consiered this idea. How about installing a schrader valve and pressurize you tank with air. Use a floating top plate to fit your tank and pump up to say 15lbs pressure.

If you are looking for the best flow rate I would install pump inside the tank and use that and have no worry's about flow rate.

 

[Joe2Lmaker]

It would be advisable (assuming it's feasible) to increase the distance between the bottom of the stock tank (where you will install your bulkhead fitting), and the bottom of the aux cell (depicted by your red line above).

... if you are absolutely dead set against raising the floor of your aux cell, ...

I'm not absolutely dead set against anything.

I went to the trouble of illustrating my Z=0 line because I suspected that I might run into a problem.

W.C., Thanks for posting when you did. You saved me quite a bit of money. I'm still not sure what I'm going to do with this little setback, but better to find out now than after the tank is built.

Shit.

You know what really sucks?

I could hardly wait to get back from First Thursday so I could post this:

NMdcporter started a couple of threads recently that ended up discussing 4 gallon polyethylene fuel cells. The contours of the FJR made me wonder if maybe we should be mounting ours "upside down". I even volunteered here to test the idea.

Nobody else seemed interested, so I figured "screw 'em!" and I ordered the part to test my idea. The part was waiting on my doorstep when I got home from work.

Take a look:

[SIZE=36pt] [/SIZE]

I think it looks pretty good (for the money) sitting on my bottom plate like that. People wanting to save a few bucks might like this solution. I’m still going to finish my 4.8 – 4.9 gallon custom tank, but I couldn’t resist checking into this.

I still like both designs, but I need to work through the height (Z=0) concern.

Suggestions?

 

[2WheelTiger]

My question is: What's the real aversion to using a small, relatively low pressure electric fuel pump? I don't see a problem with using one, and we could even build a circuit that only allows the pump to be used when the main tank is low. (e.g. Auto shutoff above 3/4 tank.)

 

[SkooterG]

Hey Joe - that plastic cell on your plate looks good. How will you attach it?

I also like the idea of your custom cell. As for raising it, I think it a good idea for fuel transfer. I tend towards the simplicity of gravity feed. Let me also say this: by raising the cell a bit, you add some much needed storage space as far as I am concerned.

Kudos for trying this. It's no easy project. And there is a need out there for a decent fuel cell. Me, I love my Tanji and it's 'flatbed' design. I am not a big fan of the topcases, dut to the high speed aerodynamic/handling issues and putting weight up high and aft. Regardless, well done on trying to figure out an intelligent, and well thought out solution.

 

[Catfish]

Hey Joe, one thing I've learned about transfer rates with my Givi cell I showed you was that I actually liked the idea of a slow transfer rate.

I never get to do any WOT for 11.5 gallons like some of the members out west so I used 1/4" line throughout.

Transfers slow but faster than I can use it so it's perfect for me.

If you raise the cell you get a faster flow rate and some much needed storage, if you keep it slammed down where it is you lower your weight in the frame (marginally, I know) and if you were to strap a bag on top of it that's and extra inch or two of that bag that will be out of the wind.

Six of one, half dozen of another.

 

[weekend rider]

Here is another Idea for gravity flow.

With the line comming off the tank increase its size than reduce it as you are close to your main tank hook up, Kind of like a venturi effect.

You have volume than pressure at the reduction.

The nice thong about thos is you can do a mock up at almost no cost :construction:

 

[Joe2Lmaker]

Hey Joe - that plastic cell on your plate looks good. How will you attach it?
I also like the idea of your custom cell. As for raising it, I think it a good idea for fuel transfer. I tend towards the simplicity of gravity feed. Let me also say this: by raising the cell a bit, you add some much needed storage space as far as I am concerned.

Kudos for trying this. It's no easy project. And there is a need out there for a decent fuel cell. Me, I love my Tanji and it's 'flatbed' design. I am not a big fan of the topcases, dut to the high speed aerodynamic/handling issues and putting weight up high and aft. Regardless, well done on trying to figure out an intelligent, and well thought out solution.

My plate will attach to the bike using the two flanged, hex head screws that hold the grab rail down. I spent a lot of time designing components that would lock the plate into the same retaining system as the seat uses. My idea was: take the seat off... click the tank in. I've abandoned that idea and I've decided to have it bolted down.

The weight on the plate will be transferred to the frame on the same points that currently take the load from the rear seat.

The plastic tank will then be strapped to my plate. It's another tangent for me, but I'm going to mount the plastic tank and post photos in the next few weeks.

Dean Tanji's design was my original inspiration and now I'm working on three or four versions of this thing:

1.) An over the tail version with a flat top (a total rip-off of Dean's idea)

2.) The rear seat replacement (a total rip-off of Bearly Flying's idea - only mine is for the GenII)

3.) A "Cheap Bastard" version using the 4 gallon plastic jug ( a total rip-off of Iron Maiden's set-up)

The seat replacement and the Cheap Bastard version both utilize the same bottom plate. The over the tail version uses the same curves on the bottom plate, but it's longer (obviously) and sides are shorter (more squat)