1957 Chevy truck re-rebuild

[dsraven]

will you instann a drain plug in the bottom as well? always good to be able to drain it for any kind of repairs needed. whether thats for the tank or something else that requires the tank to be removed. a drain at one end or side would be good so the truck could be tipped that direction to get as much fuel out as possible.will you have a dedicated tank vent or rely on a vented cap?

[dsraven]

install, not insann.
hey, its early, haha

[Rickysnickers]

Come on Dennis, have your coffee before posting!!! LOL

[dsraven]

Haha, sorry about that. I'll try harder.

[Stepside Jim]

About the drain, I'm one step ahead, Looking at the under truck pic in my previous post, on the passenger front corner I've welded in a 1/4" NPT bung.

The cap will be sealed, there will be a safety check valve and it will vent within the dr. side wheel well.

This subject brings me to another idea I have. I'm not totally comfortable having an in tank pump. I do realize there are millions of cars on the road using the same type of pump I'll be using. Still though, I'm old school, if a frame mounted pump or mechanical pump fails, I can change it on the side of the road. When I welded in the 1/4 inch bung I knew I could use it as a drain or an outlet for something else. More on this later....

Once the tank was bolted up I lowered the truck to the floor and looked from all angles. The tank being silver made it stick out to see how low it is. I then used black tape and covered the bottom inch, then stood back and looked. The one inch of black hid the bottom inch from view and I really liked the height of the bottom of the tank. My goal is 20 gallons, approximate measurements with removing 1 inch from the bottom is 20.01 gallons. Time for the 4 1/2" cut off wheel. I figure with the original tank of 16 gallons and adding 4 gallons will give me 50 miles more on a road trip, I'm good with that.

My design was also to not have the tank look like a square box hanging under the rear bumper, it lined up great to the rear bumper in the picture of the rear of the truck. This pic is after cutting 1 inch from the bottom. I also have the bottom panel welded in place so it is all the lower as it'll be. I'm very pleased.

Thanks Rickysnickers, for rotating my pics along the way.

[dsraven]

Looks good. I was going to suggest a tapered cut for the bottom and also would suggest a 3/8 or 1/2" not bung. 1/4 is ok for a drain because the plug comes out for that. A 1/4" fitting has a pretty small I'd to flow fuel from for pump supply.
Lots of shiny tanks get rock guard sprayed on to hide the shiny. You may also look at simple decal material too.

[Stepside Jim]

On the idea of covering the aluminum tank....already got it covered.

Something mentioned about using small fittings for gas supply.

As you can tell, I work with theory and in some cases how I can use theory to alter or change the normal way of doing things to my benefit.

I'm sure there are facts and figures on my next question, but just for conversation....Where we used to suck /pull fuel out of the tank, of which we know fuel pumps are not efficient doing, to get the fuel to a pump that at most will create 5 or 7 pounds of pressure. We worked with this design for 100 years.

Now, lets say on my truck going to a different delivery mode. The pump actually sits in the tank, no suction really to begin moving the fuel. The fuel coming out of the tank will not be at a negative pressure, quite the opposite, I believe the pump will be capable of nearly 100 pounds of pressure.

With these two methods, how small of a fuel line can be used with a high pressure pump to move the same amount of fuel as a 3/8" fuel line using an old style pump.

I personally haven't looked into the answer, I just notice the recommended line size seems to be smaller when using the high pressure pump.

[jwhotrod]

volume of fuel is dependent on the size of the line not pressure as you said above. the fuel pump will survive longer in the tank not only because of the efficiency of pushing rather than pulling fuel, but also because the fuel in the tank cools the pump motor. my in tank pump in my 35 chevy street rod has lasted 7 years so far where the old inline pumps would fail after 3-4 years. don't use anything smaller than 3/8 (6AN) hose, tube and fittings. also don't use more than 12" of rubber hose in the supply line.

[dsraven]

My thoughts too. Rubber is for connections where a threaded fitting isn't convenient. Steel line is preferred due to waaay less friction loss

[dsraven]

since a fuel pump is a vane style pump it will add pressure capabilities to an existing pressure found at the inlet of the pump. vane pumps create flow and will create pressure, up to a limit, should there be a restriction in the system downstream of the pump outlet. the restriction is commonly a carb or fuel injection system regulator. it can also be the fuel lines if they are restrictive. dead heading a pump will shorten the life of the pump due to heat build up. there is a whole formula for figuring out the friction loss in a given delivery system and it would include such things as fittings, filters, regulators line size etc. if the ID of the line is doubled the capacity of the line is quadrupled. every fitting, as well, creates turbulence in the laminar flow of the fuel as it passes the fitting or a sharp bend in the tubing.with that in mind try to keep your fuel lines as straight as possible and with the least amount of fittings and connections. rubber hose is bad for fuel flow so should be used sparingly. if you were to check under a more modern vehicle with the type of fuel pump, filter, regulator and injection system as what you plan to use you could get a pretty good idea of what size of delivery lines you will need. pay attention, also, to how straight the delivery lines are, that the system is grounded at both ends and the number of fittings is minimal. if the fittings were to be checked on the inside diameter I would think they too would be close to the ID of the delivery line. inline pumps would generally have a larger inlet side plumbing than outlet side because, for a vane pump, the fuel is actually pushed into the pump by atmosheric pressure. that is why there is a limit to how much a vane pump can draw in height from the fluid source. as a professional firefighter,when we draft water from a pond or a swimming pool, we use a positive displacement pump to lower the pressure inside the pump cavity so the atmospheric pressure has a better chance to push the water up the hard suction hose into our fire pumper. here in calgary, at about 4000 ft above sea level, we are limited to under about 10 ft of height difference from the pumper inlet to the surface of the pond. obviously the inlet hard suction line is larger than the proposed outlet lines would be and also limited in length. the longer the outlet line the higher the pumper needs to be set to achieve the same pressure at the nozzle. an uphill grade from the pumper to the nozzle also elevates the pumper pressure as does any fittings placed in that line. the same theries could likely be applied to a fuel system since they use a vane pump as well. a fire pump likely has a better pump cavity olute design though.

[dsraven]

wow, sorry man. that got long winded. lol.

[Stepside Jim]

jwhotrod, In the Tanks on line parts description they did say the 6an would work fine up to 600 horse power and the parts they sent were based on the 6an size. I should be in good shape.

Also, Dekalb Il. hmmm, I worked at a place on 38, the railroad tracks passed by there, McDonalds on the right. Post Office out the front window, where was I?

[Stepside Jim]

dsraven, I kind of figured there would be test and figures on flow rates, ect.

I was just thinking out loud on how those figures would change from a pump that produces 6 pounds to a pump producing 80 to 100 pounds.

Plus how we now commonly use bypass/return lines off our regulators. I figure the return line system has to make for happier pumps since they are not pushing up against a dead end anymore.

I got away from the Hot Rod world for about 10 to fifteen years, then got back in about 13 years ago, and I'm still catching up.

[jwhotrod]

you could have been at NAPA, Rositas, Keith and Ralphs, or Gordons Hdwr. i live East of there on RT 38

[Stepside Jim]

jwhotrod, Way back in 1992 I was working at the NAPA store there in DeKalb. I was mainly a Belvidere resident, I got to ride in the Tornado in a school bus back in 1967.

It's time to get this tank and most of it's pieces fitted and in place.

The fill cap is logical, the sending unit is logical, the vent tubes are somewhat logical, what's up with the fuel lines?

I'm coming away from the tank with Steel braided lines and I didn't want to have to lower the tank to get to the connections so I chose to use metal lines to the edge of the tank and make a support that is raised high enough so when the steel braided lines attach to the tank fittings I'm not dealing with the cross frame that the rear shocks mount to.

The metal lines are firmly clamped to the support. I was able to use the support to secure the wires for the pump and sending unit also.

Now when the tank is in place I just need 2 wrenches to remove the lines and I can do this from the bottom side.

[jwhotrod]

below i am adding photos of what i have done with mine. i always come off the tank with braided hose to hard line going forward. I will not use that fill cap in my tank, i will add a neck when i get the box back on the frame and take it up into the drivers side fender, i feel that putting a fill in the box floor is a cop out and if you spill fuel in the box whatever is in there will smell of fuel. i run long distance quite a bit of the time and dont need my luggage smelling like fuel.

[dsraven]

I'm with you on the in bed tank fill. I like to carry stuff in the bed so I put my filler on the fender. it's not a show truck anyway but if it was there are ways to make a fender fill fuel door look very nice without using one of those sports car style bolt on doors.

[Stepside Jim]

jwhotrod, that's a lot of craftmanship going on there, it makes my project look like the SS Minnow.

I see the section removed from your cross member for the fuel lines to pass by easier. This gets me to the tank fill cap....I'm with the both of you on the fill cap being outside the bed but since I'm all painted and together, well....I just had to settle.

Mentioning taking long drives, I see a couple in my future, I haven't been to Northern Il. for 18 years now, maybe this year.

[LT7A]

I've really enjoyed reading this thread. I didn't see it during the initial build but it is really cool to see all of your fabrication process, beautifully finished work, get the tips you posted, and hear your thought process along the way. Such a great looking truck. I know I'm interested in seeing it out and about and how you're enjoying it. It's always cool when a build thread transitions into a "drive" thread.

[Rickysnickers]

I couldn't get your second photo straight, so here it is in a separate post.

[Stepside Jim]

Thanks LT7A, I appreciate you checking in. Your writing tells me I'm on the right track. I got caught in a build thread of somebody else many years ago, it also gave information, reasons why certain decisions were made and showed the build process along the way. When I say "along the way" I mean not just what was done but how it was done. Also perhaps the tools, the products and craftsmanship along the way.

One product I've come to use often, not only for it's electrical purpose but for strength and visual purposes. Good ole heat shrink tubing. For instance, I'm using stainless steel braided hose on the project. It has a nylon covering that can be snagged especially when pushed into a tight area. I buy my heat shrink "with adhesive inside" from Amazon in 4 ft rolls. Many different sizes available.

One such area is the vent tube holders I've welded on to the tank. I made the holder so that the tube actually snaps into the holder, the heat shrink gives a good snap fit and protects the nylon covering.

Next up, newer style fuel level gauge. No more swing arm with a float attached. There is a small hole or the fuel to enter and raise a float within. I haven't used it yet, but I thinking it will help keep the gauge from being sensitive and reading fuel slosh on our early design gauges.

[_Ogre]

i was interested in your fuel gauge sending unit. does that work with the oem gauge?
how tall is it? link?

[Stepside Jim]

Originally Posted by _Ogre

i was interested in your fuel gauge sending unit. does that work with the oem gauge?
how tall is it? link?

Yes, it works with the oem gauge, in the listing you have to pick the Ohms range of the gauge you're using. My truck being 0 to 30 ohms I hooked it to the gauge and grounded it dry. With slowly rotating the sending unit and making the float within slide up and down in the tube, my gauge worked and showed the movement of the float.

It is listed by 1 inch increments. My tank is 8 inches deep where the sender is mounted, I welded in a sender bung for threads in the tank. Along with the gasket also I have about 1/2 inch from the bottom of the tank to the bottom of the sender.

These, along with many other odds and ends I found at Tanksinc.com website.

[dsraven]

nice clean work and well thought out. great job.
I use the shrink tube idea for lots of stuff other than electrical as well. there are lots of different types it seems but I prefer to go to an electrical supply place and buy the double wall stuff, with the hot glue type inside, and it is fairly stiff so it doesn't actually roll up but rather comes in 4 ft lengths or longer. it is a little harder to cut off a piece because the cut ends usually try to stick together. overcomable for sure. it works well for stuff like you are using here on the hose.

[daveshilling]

Originally Posted by Stepside Jim

One such area is the vent tube holders I've welded on to the tank. I made the holder so that the tube actually snaps into the holder, the heat shrink gives a good snap fit and protects the nylon covering.

These are the little touches that I really love...when someone could justify a zip-tie somewhere, but they take that extra step that only a DIY guy or a super high end shop would do.

Awesome work!