1957 Chevy truck re-rebuild

[Stepside Jim]

Changing from the Th350 to the 4l80e has taken space where the old X pipe for the exhaust cross over from side to side.

My next choice is going to an H pipe. Why go with either one, sound, my exhaust exits both sides of the truck and I want all 8 cylinders sounding on both sides.

The X pipe did this easily since all 8 cylinders mixed at one point. My issue with an H pipe is the exhaust doesn't travel and mix together, the exhaust pulses hit each other in the middle of the H pipe but nothing really travels back and forth.

I came up with what I hope will solve my problem and only need the space of an H pipe. I call it Strex pipe, a stretched X pipe.

The pics will tell the story, in short, cut lengthwise the H pipe, slip in a piece of 18 gauge sheet metal, now the pipe is two pipes in one once welded back together.

Place angled fins to capture exhaust on one side, send it through the split H pipe, where the angled fins direct the exhaust to exit and flow with the exhaust in the other side exhaust. The exhaust from each side passing through the H pipe never touch each other making a free flow yet mixing all 8 cylinders together in the end.

I haven't started the truck with this setup, but hey, this is Hot Rodding. There's something about thinking and always trying to find new ideas that keep me moving forward.

[Stepside Jim]

Trans rebuild was almost done, I had all the internals in place. Then I was watching YouTube and realized I thought I had all the parts for converting this 4x4 trans to a two wheel drive...Reluctor ring, the cogs are what the speed sensor uses to tell tell the ECU the tail shaft speed. First time dealing with electronics in a transmission.

Amazon got one to me in 2 days, and I saw where another fellow put one part in the freezer and heated the ring and they came together without a press. Sure enough, I froze the drum and heated the reluctor ring with my heat gun to 250 degrees, just a small tap tap and a perfect fit.

Nervously I finished the reassembly and tried to cover every issue along the way.

Next was mounting the TCI ECU box, I had plenty of space under the drivers seat, and sent all the wires down through the floor. I had to mount a Throttle position sensor and module to use my HEI RPM output. Had the main harness for the trans and the tail shaft speed sensor wires also.

Lets see, had to have the driveshaft shortened, remake some of the crossmember, changed up much of the exhaust, change the shifter to accept 4 speeds and also changed rear gear ratio from 3.73 to 4.10.

Around 7 quarts of trans fluid and lets see what happens....oh, and around 28 ounces in the gear vendors overdrive.

Fairly uneventful, just as you'd want it to be, let it run for about 30 seconds and add 4 more quarts, start again, try reverse, yup, try forward, yup.

No leaks, check all bolts, check fluid level, add as needed. Back out of garage, slow roll to street, take off slow, second gear and so on through to fourth gear.

Only about a mile drive, back home check fluid level, no leaks, another test drive. All four gears, switch on Gear vendors over drive, then switched on lock up converter, all worked.

More to the story for later, but I have check my speed with GPS to my RPM. At exactly 60 miles an hour with 4.10 rear end, both overdrives and locked converter I'm happy to say 1650 RPM, mission accomplished.

[Stepside Jim]

The 4l80e was nearly a perfect switch except for one issue, one that I hadn't heard of until now with this set up.

This truck is to have great off the line torque/drive, that's were the 3000 stall converter and 4.10 rear gears come into play.

I also want low rpm highway cruising speeds, that's were double overdrive and lockup torque converter come in.

My test drive showed an issue coming to a complete stop at idle in drive. The torque converter pulled/dragged the engine rpm down about an extra 100 to 150 rpm. The instant I began to roll, the torque converter would free up to a normal stall loose feel, stop immediately and the drag effect would happen.

Thanks to the internet, since the tech line that I called was pretty much no help, I found I wasn't the only one to experience this dragging issue.

Installing a shift kit raising pressures and a multidisc lockup creates a sensitive pressure situation. Thanks to Sonnax products, they make a pressure relief built into a valve up in the pump. Installed and went for a 30 mile drive yesterday, all seems good now.

Next on the to do list is making a Gas Tank for under the bed. I've just never been happy with the ones I see available, so here goes. Staring with a carboard mock up. I'm looking for a little over 20 gallons when done.

[Rickysnickers]

There was a post today where another member was asking about the possibility of installing a 4L60 into his '57. Your fits. did it require any modifications to the floor or transmission tunnel?

[Stepside Jim]

Rickysnickers, I put my 2 cents in...

Ok, gas tank, yes, I wanted it out of the cab when I built the truck for two reasons that are not commonly mentioned.

First, I can very slightly smell the gas while driving down the road, it's barely detectable. I'm not happy with my sinuses because, I have to have everything fragrance free or I'll get dizzy, it's a pain in todays world were even with garbage bags I have to look for fragrance free.

So, over a long drive I start feeling light headed, out comes the cab tank.

Next, the factory tank has no baffles, if I want to get heavy footed and drift sideways, and with the tank being long, side to side, and I don't have over 1/2 tank of gas, I will starve the pump and run lean.

I didn't much like what was available when I built the truck, most were hanging lower than I liked to get near 20 gallons. I didn't want to remove the cross frame that went between the rear leaf spring shackles to get a higher sitting tank back then.

After having issues with frame mounted electric pumps and hearing them run I've decided to go with an in tank pump.

I contacted Tanks inc, for advice and parts, very helpfull.

When done I should be around 21 gallons, under bed, quiet pump, baffled, fairly out of sight of which it will also be painted satin black.

The cardboard mock up gave me an idea of size and fit. Then slight redesign, and off to the plasma cutter.

I'm going with 1/8" aluminum and will weld near 30 feet. I don't have a press to bend 24 inches and my sheet metal pan brake will not bend it either, so I'm stocked up on welding rod and Argon.

Disclaimer, I'm not disassembling the old tank till this new one is done and I'm confident with it. It's Hot Rodding, I like to raise my bar and push my limits, so here goes.

[Rickysnickers]

I saw that, thank you

[Stepside Jim]

I've been putting miles on the new transmission, so far so good. Using the TCI ECU, I've been dialing in my high speed shift points and my low speed shift points also. The Sonnax valve is working perfect, no more dragging feeling at idle in gear. The new exhaust sounds spectacular. The 4:10 gears, more fun to drive than before.

Gas tank is coming along, my aluminum welding has significantly gotten better. You can practice Tig welding scrap pieces all you want, it's not til you want to weld 24 inch welds over and over til you know you're getting it more figured out. Then have to weld 1 inch diameter bungs for vent fittings and a 1/4 npt outlet.

After some very accurate measuring I committed the Plasma Cutter to cut the side panels. I need very close accuracy so the fit up will give me the perfect "v" for welding the outer edges.

Yes, baffles, I decided not to do the big baffle thing, let it slosh. I chose to focus on keeping 1 1/2 gallons at the pump inlet. My holding area has slits cut in the bottom to allow gas to fill the holding box, but keep the gas in there while hard turning and acceleration. Having the bottom of the tank tapered to the holding box I believe will help.

Pictured is the in tank pump from Tanks inc. More on that later..

[Stepside Jim]

When I looked at the pictures of in tank pumps that will work for homemade gas tanks I never saw a close up to fully understand how it all fits and works. So here's a better pic.

One unit takes care of mounting flange, an adjustable capture tray, high pressure pump. The top mounting plate has 3 pipe thread openings. 1) for main pressure out line, 2) bypass regulator return line in and 3) vent line. I'm not using the vent line, simply thread in a 1/4" npt plug. Oh two wire holes to feed wires through. They installed special compression fittings to seal the wires.

The fuel pump has a specific sock that is a pre-filter attached.

The next pic is a better pic of how I decided to manage the gas getting into the gas capture area.

[oldman3]

Hey Jim

I'm not an engineer, or anything close to it. Nice work on your tank.

I believe all liquids, seek their own level. If so your taller tank will only fill to the same height as the shorter tank. It would have to be under pressure to overcome the difference.

You can do a test on the tank before installing, by adding water through the fill. You may be a few gallons less than than what you think.

I could be 100% incorrect, let me know how it goes...Jim

[Stepside Jim]

Ahhh, I started to reply a theory, then I clicked back to see what pics I've posted and what they show.

The two openings showing in the lower section seen is the large opening for the pump, it's 6 1/2" diameter. The smaller opening is for the sending unit. These two I was able to measure and plasma cut when I cut the top panel.

One opening in the pictures not shown is the gas cap opening, it will be located in the higher level on the drivers side. I wanted to build most of the tank then get it in place and mounted. Without the bottom panel welded in place, I'll measure closely where to hole saw the gas cap opening. Once I made the opening in the tank, I'll put the tank back in place and use it to sharpie mark the hole in the bed.

Thanks for checking in oldman3,

[dsraven]

I just dropped the tank in a gmc envoy and that thing has a shape sorta like this, a couple of high spots. GM has vents at the high spots to allow air to escape when filling so you can get an actual full tank and also, I imagine, so it doesn't burp back through the filler when the bubble in the high spot decides to move when filling. also so it doesn't take forever to get a full tank.
I just dropped the tank on my project that is sitting on an 04 gmc envoy frame. the fuel pump croaked. the tank is very uneven on the top but it also has vents on each high spot. the filler is at the rear and each area where there is a tie down strap, and corresponding crossmember, has a corresponding low spot in the tank top.
https://www.gmpartsgiant.com/oem-gmc...fuel_tank.html

[dsraven]

dunno what happened there but I started a post and then it got lost so Irestarted it and hit post, then it has both parts. oh well, you get the odea anyway.
use a larger hose for the vents that connect the high spots, I think the envoy vents through a cannister but as long as the highs are connected it should still fill.

[dsraven]

make sure the gaskets on the two holes in the lower part are good solid gaskets because thats where the leak will be, if anywhere, due to a partial tank of fuel being above that level when the tank is full

[dsraven]

having the sending unit in the lower section means that the first portion of the full tank is going to read "full" until the tank is used and lowered to the level of the lower section. correct?
how tall will the filler neck be, in your estimation?

[Stepside Jim]

Ok dsraven, you are right on target.

The filler neck is around 1 1/2 inches long depending on if you count thread length. I bought one that was called a 2 inch and I cut 1 inch out of it. I figured every bit I could keep the tank up to the bottom of the bed is all the higher I could raise the bottom of the tank.

You mentioned venting the tank at the high points, yes, the vents are what will in my theory, allow the two step tank to work. There is a tee at the back/higher section. This tee allows the front section to breath into the tee when being filled, the higher section also breathes into the tee and there is a line coming off the third tee outlet that will 90 degree around the back of the tank for fresh air.

dsraven, you are correct on the gas gauge waiting till the level drops, I figure around 25 to 30 miles before the needle starts to move.

The vent hose coming off the front section has a upward curve for two reasons. One, it can't pool gas in it and block air flow. Two, it curves up over the cross frame that gets in the way of most under bed installs.

More to come.....how did I attach the tank to the frame, where does the vent hose go to, how did I support the hose across the rear of the tank and be assured to has a slight upward angle, what to do to make steel braided hose attachment possible without dropping the tank. Oh, what 5/8" miscalculation did I make that makes the back of your neck sweat and you're heart rate raise.

[Stepside Jim]

I'm gonna get away from the gas and vent part of the gas tank build and focus on how to mount it to the frame.

What I don't want and what I do want and how to make my wants work.

I can't use straps easily since I've left the cross frame in place and many aftermarket tanks will have a welded 90 degree mounting plate to both sides of the tank and bolt directly to the frame.

I'm not fond of the 90 degree mounts because I see aluminum welds as being susceptible to fatigue cracking as the frame has slight movement and the tank doesn't want to twist along with the frame.

I'm going with 4 mounting points, using rubber donuts between the tank mounts and the new mounting points from the frame.

The pic below shows the steps to fit the aluminum tank mounts together and the other pic is the mounting tabs that mount to the frame.

Fortunately the frame already has factory holes to bolt my mounts to. I am also always looking to make my life easier so when ever possible,, I will weld the nuts in place, makes everything so much easier later.

[dsraven]

Try to make it easy to get the tank out as well. Without taking the box off the truck. I cant tell you how many times I have cussed out an engineer or manufacturer for putting stuff together in a way that looks good on paper but makes it really labour intensive for the guy fixing it.

[Stepside Jim]

We'll take care of the ease of install today, and a little more of ventilation.

I am fortunate to work with a lift. One of the first tools I bought was a transmission jack. Along with the transmission jack I ordered a kit to use the transmission jack as a Gas tank removal and install unit.

First pic, more of ventilation. I figured I'd use braided hose to continue the vent, problem is, the braided hose will droop without support. I didn't think drilling hoses in the tank and using self tapping screws to use clamps wound be wise.

This is the time to think ahead and foresee and solve the simple issues. I used 1 inch I.D. aluminum tube, cut in half, shaped to fit the hose diameter, weld to the tank guaranteeing an upward angle. The vent will continue to the inside of the dr. side wheel well, I'll get that later.

Second pic, no bottom welded in place yet. I wanted to get the tank in place and mount it, then lower the truck and see how it looks concerning distance from the ground and how much it hangs down in sight. Strange enough, 1 inch removed from the bottom made a big difference in seeing the tank from the sides and from the rear. With this 1 inch removed I still stayed just over 20 gallons of which is my goal.

Second pic, easy install, raise tank up, run mounting bolts through the rubber bushings and mounts. No nuts to hold onto since they are welded to the frame mounting tabs.

[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.