Fuel Tanks & Mods

[Kinarfi]

Sorry guys, when I read your first replies and you mention valves and other stuff, I wasn't sure you had my picture or my idea down pat, so I redrew the picture and replaced the old one and I wasn't sure you'd go back and reread, so I put that big red post for you to see. I'll go delete all the big red posts. I also redrew and numbered and colored the drawing.

Now for my Lenny type explanation. Sorry.

as the fuel drains out of green 1, it will stop draining at the red level line. The yellow line will stay full and so will the junction, it can't can't get any air. As the fuel is draw off by the pump the yellow line and the junction will stay full until the air enters the lowest point of the yellow at 2. At this point, were out of gas. The level of the fuel in the green line will depend on the free flow out of the tank at 2 and the drag of the yellow line. The blue pump line will pull 50gph, if the yellow can not supply that, the green will empty and the junction will fill with air. If the return is sent to the junction, then the yellow line only has to provide the fuel needed to run and I believe that the 5/16 lines can handle that with ease and we should be able to run the tank dry.

Jeff

[4x4x454]

If this can be made, I think it would work, no concern with the return, not sensitive to how high or how low it's mounted. Use a smooth bore tube with snug fitting steel ball that when it rolls to the lower end, it's weight seals up against the green seal, o-ring, and prevents air from being sucked into chamber. Two outlets so can't be stopped. As the hill gets steeper, the force of the ball on the seal get greater, sealing better.

Still working on this post, I'll add a drawing later.

Jeff

Picture this, 1/2" ID brass pipe internally threaded with 1/4 nptX5/16 barb on each end, each of then drilled just enough for an O-ring to into, two 1/4" holes drilled into the pipe about 3/8 c-c apart and angle away from each other, grind off a fitting to match the pipe and braze or solder it over the holes and put another barb fitting on it.

Would this work if it had a floating ball in it insted of steel ball it would float up and and get sucked into the upper end?

[Kinarfi]

I don't know, I have abandoned the valve idea for now except for the pendulum idea.

My favorite right now is this one, click on picture. When I was looking a Lennys drawing, http://thumb18.webshots.net/t/74/74/1/64/4...58rDYlTd_th.jpg, I realized that his little chamber would stay full because of the siphon effect and if I extended the lines past the end of the tank and I figure that as long as both outlets don't uncover, the junction will stay full. The only problem I see is the volume that the pump moves, the solution is loop the return line to the junction and the all that's needed is enough flow from the tank to run the engine, not a very big volume. But that brings in another problem, if air get in the line, how do you get it out? Feed the return into a Tee and let the air go to the top of the tank and the fuel to the junction.

I've got some more testing to do, but I'm waiting for parts.

Jeff

[Guest Lenny]

The shuttle valve I made up just didn't work to solve the prob;em. The valve assembly itself worked just as expected and would seal tightly. I've decided that the pump pumps so much volumn that it is strong enough to pull the valve open even though it has 4 steels balls holding it. I had 2 gallons of gas in it, put it on a 45 degree downhill slope and it ran out of gas about as fast as it did before. Also, now it would run out of gas going up a steep hill too. The trooper also lacked power 50% of the time. It just didn't like the whole thing. I'm beginning to think that with the pump pumping that hard, It's going to suck air whenever it can. The shuttle valve just made things worse.

Here is another idea. How about using a 1 quart canister with the pump pulling off the bottom. Then have a second fuel pump pumping from the main tank to the canister with a return line to return surplus gas back to the tank. If the canister had a funnel shaped bottom, gas would always be available even though the second pump may run out of gas temporarily because of going downhill. The second pump would want to be mounted low to always reprime itself.

Your thoughts, What size tubing are you using, can you post a drawing of what you have or photos.Jeff

Lenny

[Kinarfi]

If you're going to add another pump, add another filter also and a shuttle valve, now all you have to worry about is do you have too much fuel flow.

Did you analyze my last 3 drawings? Especially the how I handle the return.

Waiting parts, expect them on the 20th. If you have some clear tubing, fill a length with water and hold the end together, now while the ends are still pointing up, raise any part of the rest of the loop above the ends. If you have enough tubing to hold the center of the loop high and still have the ends pointed up, like a W with a high center, move one of the ends higher than the other end and then back. Where's Mister Wizard when you need him?

[flatbed]

Since i have added the sump to the bottom of my tank, with the suction and return line going to it i have not had a problem, before i welded the sump on i drilled holes where the sump was going to be in a patern of 5 like on a dice, so the sump would get plenty of fuel to the suction, but still be able to have the return line not contaminate the suction with hot fuel. I have not had a problem running out of fuel going up or down hill.

[Guest Lenny]

Since i have added the sump to the bottom of my tank, with the suction and return line going to it i have not had a problem, before i welded the sump on i drilled holes where the sump was going to be in a patern of 5 like on a dice, so the sump would get plenty of fuel to the suction, but still be able to have the return line not contaminate the suction with hot fuel. I have not had a problem running out of fuel going up or down hill.

I'm beginning to think your sump might be the better way to go. It's sort of my nature to say, I can get every last bit of gas out of the tank. Then I set out to do it. Needless to say, it sure can complicate my life nor do I need to get every bit out. I do however have fun doing it and it's a great way to learn. I may also just build another tank t replace the existing one. The area will hold a somewhat larger tank. I'll just put a vee bottom in it. Maybe I'll just do nothing and brainstorm for awhile.

If I do that, stand back and don't read anything I post for a while. Give me time to stabilize first.

Right now, I going to go in the garage and stare at what I did and keep telling myself, "I CAN DO THIS"

Lenny

[flatbed]

Lenny, if it is pulling the balls away, the orfice is not big enough on the side it is drawing on, go big so the volume you can pull through does not need it from the other side.

[Kinarfi]

Since i have added the sump to the bottom of my tank, with the suction and return line going to it i have not had a problem, before i welded the sump on i drilled holes where the sump was going to be in a patern of 5 like on a dice, so the sump would get plenty of fuel to the suction, but still be able to have the return line not contaminate the suction with hot fuel. I have not had a problem running out of fuel going up or down hill.

You have a good system, no doubt, but I don't have a welder to weld the chamber on with, shame because I have an extra tank to cut parts off of. If I had the equipment, I would weld 1/2" ID fuel direction reversal lines to the to the bottom of my tank with a 5/8 hose fitting at the junction, that's what the hose to the pump is.

Lenny, if you have time, wait till I get my parts and make a test or two. My logic says the reversing line should work.

Jeff

[Guest Lenny]

I don't understand why we should need such a big line. the stock outlet leaving the tank is I beleive .230". Anyway I'm going to try the Pipe gas setup that I sketched out a while back. Nothing mechanical. The 1 3/4" Id pipe will be aprox. 12" long. It will set against the bottom of the tank and have two 1/2" dia holes going into it straight down from the tank. one at each end. The pipe will run right to left across the tank. I will run the return line into the end and the outlet will be on the bottom center with a 1/4" x 1/2' long slot going directly down through the bottom of the pipe to it's outlet. This outlet hole reduces down to a hose fitting with a .290" dia. hole which is larger then the stock outlet.

You may be right flatbed, going to a really large valve ports may change things. I'll try to do a drawing tonight of what I did and post it.

I'm having a ball.

Lenny

[flatbed]

sounds like more than one (ball), the 1/4 inch works because that is the only place it can draw from, these pumps pump alot of fuel at alot of preasure, it will do everything it can to suck the fuel into the pump, when you get done the engine might run better because it maintains a better constant on the fuel preasure, we are only able to read the fuel when we are setting still, it might be droping undr full load.

[Guest Lenny]

You have a good system, no doubt, but I don't have a welder to weld the chamber on with, shame because I have an extra tank to cut parts off of. If I had the equipment, I would weld 1/2" ID fuel direction reversal lines to the to the bottom of my tank with a 5/8 hose fitting at the junction, that's what the hose to the pump is.

Lenny, if you have time, wait till I get my parts and make a test or two. My logic says the reversing line should work.

Jeff

If you need your tank welded, send it to me and I'll do it for you. No charge just pay the shipping. I'll just have to pick a day i'm steady so I don't dip the tungston too much.

Lenny

[Guest Lenny]

sounds like more than one (ball), the 1/4 inch works because that is the only place it can draw from, these pumps pump alot of fuel at alot of preasure, it will do everything it can to suck the fuel into the pump, when you get done the engine might run better because it maintains a better constant on the fuel preasure, we are only able to read the fuel when we are setting still, it might be droping undr full load.

Ok, I'm starting to get the picture. If I were to go bigger, I would also need to go to bigger balls. Keep in mind, it's not the suction that opens the valve but the atmosphere and any gas head that is pushing from the other side that pushes it open because of the pressure differental. As the valve gets bigger and thus its area, It will take more to keep it closed. But I agree that the larger the open port is the less suction there will be on the closed one. I've started my pipe gas concept. It is real simple and won't take long to make. I should be able to try it tomorrow.

Lenny

[flatbed]

Lenny, i think you are on the right track, the weight of the balls should keep the port closed once you can feed the pump without having to much of a low preasure area in the tube. I guess if we ever go on a ride we will know who has the most balls!!!!!!!!!!!!!! That's bad! Flatbed, Kinarfi

[Guest Lenny]

I finally got my drawings done on the shuttle valve assembly I made. I think it should be self explanitory. I'll do drawings of my current change in the next few days. Zoom the pics in to full size to see the detail clearly.

Lenny

[Kinarfi]

Wow, good drawings, what program did you use to make these? PM coming.

[Guest Lenny]

Wow, good drawings, what program did you use to make these? PM coming.

SolidWorks

Lenny

[Guest Lenny]

Finished my pipe gas concept. Put a U shaped channel across the tank bottom about 12" long and about 2" high. The botom center has a slot cut in it. This slot is covered with a welded in tube fitting so the gas is drawn off the very bottom. The tank bottom has three 3/4" x 3-1/4" slots cut in to feed gas into the u shaped channnel. "The cap at the end of the channel has a fitting for the fuel return. This keeps the channel from running out of gas because of the surplus that is being pumped and returned. In testing I put 2 quarts into an empty tank, got the pump primed and went for a ride. I did bring extra gas with me. drove across the way and parked on a 30 degree downhill and let it set running for 5 minutes. No problems, Seems to work great. I did run out of gas on the way home on level groung. I guess 2 quarts was pushing it. Bottom line is it continued to run down hill with only 2 quarts in it starting out from home. Tomorrow I'm going riding so I'll give a further report when back.

lenny

[Kinarfi]

I got lazy and finished mine without figuring out if I need the return line going back into the pump suction line. I just put it back into the bottom where it was before. I drilled and tapped a 1/4 npt 90 degree fitting into the front of the tank, then looped the 5/16" lines to a Tee and the output from that goes to a screen filter, then the pump, the filter, the regulator and then the return. I mount the Tee in foam to keep it low and to keep it from bouncing around, the foam had to crush about 1/4" so all should stay put.

In my testing, playing, spilling gas, making a fire hazard mess, it seemed that once the pump is primed and running, getting air in the line didn't really hurt anything, so I'm going to try this setup for a while. I have clear fuel lines so I should be able to see if I'm getting air sucked in. Too cold to test right now, so on to the hinged hood project & under hood storage.

Also need to check steering box. Already did the new bolt with shank thing on the ball joints. Git er dun if you haven't yet, right flatbed?

Took a handful of photos, here's the first, click and look at the rest, if you want.

Jeff

[Guest Lenny]

I know what you mean about fire hazzard. Just don't try to start it with fuel all over. When I work on the gas system, I get my fire extinguisher ready. It's a little concerning. Put a fan blowing towards it. It will dry out pretty quick. When I weld on my gas tank, I put a fan blowng in it over nite. Not a speck of gas smell in morning. I blow it out with air anyway just before welding.

If you get a little more tubing you could probably eliminate the tank all together

Lenny

Bad idea, I have the tank, I'd have to buy the tubing!!, Jeff If I had the equipment and tubing, I'd weld 1/2" ID alum tubing to bottom where the red lines are. Jeff

[Kinarfi]

Had a new idea, if having 2 lines from the tank induces air into the line and it is still getting gas, we could add a chamber with a float in it that when it rises, it hits a float valve just like in a carburetor, but instead of letting fuel in, when it accumulates air, the float sinks and lets any accumulated air out and the out is routed back to the tank. After all, we are moving 50 gallons an hour to develop 6 pounds of fuel pressure.

[Guest Lenny]

I don't think we really have a combination of air and gas. Once the pump has an opportunity to suck air it is going to continue to suck air as it's the path of least resistance. There has to be a mechanism that shuts off the air side. The air always comes from the high side of the tank so this mechanism has to detect which side is high and provide a way to cut off flow from that side. The sump idea that flatbed and myself are using, though different in design, both omit the need to detect the high side by accumulating fuel in a chamber during normal running. The chamber doesn't really have a high and low side when on hills and thus has a reliable reserve of gas to draw from which last more then long enough to get back to more level ground where the sump recharges itself.

kinarfi, the shuttle valve (thingy) I sent you does control which side gas is allowed to be drawn from. Part of the problem was to have something that would detect the slightest slope so that it would work when very low on fuel. The rolling balls are the best approach as they will roll with only 1 or 2 degrees of slope. The problem comes in that at this small of a slope the balls don't push hard enough to seal the valve tight enough. That is why I was going to go to a rectangular rubber seal with a sharp square corner for sealing with less pressure. As I said in my note to you, I also was going to have both needles connected together by a rod that had a heavy bar anchored to it in the middle rather then the balls. This then becomes more of an either/or situation. I also was going to use a very short valve point with a close flat surface closely behind it so when gas flowed in the incomming current pushing against this flat surface would help hold the valve open on the open side and add sealing pressure to the closed end throught he connecting rod. Your pendulum idea would work to but has the same problems on slight slopes. However the hanging pendulum could have a compression spring on the top end of its wand arm which went through a over center compression. In other words, it snaps from one direction to the other as the pendulum weight swung through bottom center position providing a much more possitive closing and holding of the valve against it's seat. The sring would be at its highest compression point when the pendulum was at bottom center (vertical to the Trooper). Because of the compression still existing when the spring is at one side to the other the pendulum would be sort of held one way or the other when approaching vertical. I don't think this would be a problem but it still has me courious.

I think this is called beating something to death. But it's fun. I'm sticking with my current pipe gas consept as it's working good at any and all slopes. That is unless I put it on it's roof. Maybe I should put a sump on the top of the tank too.

Lenny

[Kinarfi]

Finally got a chance to run the Engine on a slope, the fuel never stopped flowing, however, it was full of air, so the looped fuel lines works, but needs to be larger or the air needs to be ignored, I will choose to ignore the air until it become a problem, which I doubt because of the volume that is pumped to the pressure regulator.

I could see the air in my prefilter strainer next to my fuel level sender.

Here's a VIDEOhttp://good-times.webshots.com/video/30209...host=good-times

Interesting point, the the video is before the pump, after the pump, the air bubbles were smaller and very few, oxygenated gas?????

[Guest Lenny]

Good job. I think I would be more comfortable with the air out. It probably will not be a problem but if it's out, it won't be for sure. Did you ever get the seat belts? How about the top rack?

Lenny

[Guest Lenny]

Is the source line from the tank bringing in air or is this trapped air. If it's trapped, is should clear itself out with time. How about a as built drawing, I'm curious to see how you handled the return gas.

Lenny

[Kinarfi]

The source of the air is the higher fuel outlet, the suction from the pump is pulling enough volume to pull from both sides, IMHO, because my tubing is not large enough. The return from the regulator goes into the tank, I don't know what the regulator is doing with the air, but I suspected this might happen and is the reason for suggesting the air trap that vents back to the tank.

If you click on my first picture and back track through the previous photos, you'll see how it is actually plumbed.

Kinarfi

[Kinarfi]

Found an interesting fact, the check for the fuel pump pressure is 300 kpa or 43 psi, in my opinion, that's quite a bit.

[4x4x454]

Mine runs about 60psi.

[ksimpsy]

Hey sorry im jumping in here and changing the main valve idea. But Lenny did touch on this a bit ago and it is a Surge tank and is used on 4stroke snowmobiles that are getting modded up with turbos. the main concept is the same because the sleds are going straight up or down for a long time. i talked to my mechanic buddy to make sure i got this right and it is the same as Lenny said. You come from the stock tank > filter > identical pump as stock > surge tank > filter if desired > stock pump > regulator > return line > surge tank > top of surge tank > return to main tank (basically overflow) this system keeps fuel to the engine at all times and keeps all the air out of main supply from the surge tank. any air gets back to the stock tank from the return line from the top of surge tank. this is a simple foolproof design that has been proven on sleds for a couple of years now and is the method i am going to use because it dosent require cutting apart my tank and depending on the size of tank i use i could gain probably another gallon of fuel storage. just thought i would throw this out there for all the other guys reading this thread that want a bit easier way to go.

Thanks, Kevin

(sorry about the hijacking)

[4x4x454]

Show me a drawing.