LocostUSA.com

I'd make them equidistant, no center holes, don't extend to the top of the tank so as not to affect filling and instead of clipped corners, file a few half circles in the bottom edge before insertion. The clipped corners appear much larger than the area of the pickup tube.

You are making the tank, so why not a small pocket/sump for the pump sock and return to dump into? It may be better packaging to place it a corner. No need for special mats.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

That should give you~11 gallons (10 gallons usable? ) looks like a plan. Just don't change directions and eliminate the hydramat.

I originally had a dropped sump like MV8 mentioned and never had a starvation issue. My 2nd tank was like yours but no hydramat. I had fuel starvation and wished I had gone with the sump. The modern GM pump assemblies (over the last 20+ years, and I guess Ford too) have a built-in sump that seems to work well. I am planning on using one in my MG. You have enough height to consider it.

reinforcing what MV8 said, it doesn't take much of a bottom corner notch in the baffles to equalize the levels. Smaller is better IMO. I personally like the idea of corner notches over half-holes. Those center holes are not necessary or even functional IMO.

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

How far from the top of the tank would you end the baffles? You're right about the sump, of course. Sometimes we get a bit lazy... The cost of the Hydramat is $150 or so better spent somewhere else!

_________________
Dismantalus, Fabricatus, Assemblus.....
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!

I'd make the baffles an inch lower than the standpipe in the neck hangs down, that prevents overfilling at the pump. The standpipe has a small bleed hole at the top into the filler neck.

Westfields also have a sump. They put it on the end. Dump the return into it too.

You can make doors if you want. Roll the top edge of the door over a thin rod or wire, then use copper ground wire as the hinge. Insert the wire through the baffle plate and bend one leg up and the other down. Use scrap to space the hinge out the thickness of the door. Leave a 1/2 inch around the bottom of the baffle. Doors toward the center and small so it can only get through one baffle the same as it would a baffle with a smaller clipped corner or half round.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

I changed the baffles per your suggestions, and I'm going to go ahead an do the sump, and route the return line to it. It really isn't that big a deal. But now that you mention it, I remember the standpipe in production tanks, but I have not seen ANY of the aftermarket tank manufacturers or parts suppliers even mention a standpipe, let alone have them available. And I certainly don't want to be spraying fuel all over the gas station every time I fill up, so if you have any thoughts on where I can procure said setup, I'd be most appreciative.

_________________
Dismantalus, Fabricatus, Assemblus.....
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!

They are all off-road race-only parts but some mfgs make epa approved tanks for agricultural applications:

https://flambeaufluids.com/product/3-50 ... -snap-fit/

https://flambeaufluids.com/fittings-com ... -category/

You could weld a piece of square into the neck. It doesn’t need to be round.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Ok, so it is basically a vent line from just above the baffles, into the filler neck. I can do that. Now, I know how the Gas Station nozzles sense when the product is beginning to back up, but for my edification, and everyone else that sees this, how does the vent / stand pipe effect overfilling? (You obviously have FAR more engineering background than I do..) Can't quite seem to get my head around it.

_________________
Dismantalus, Fabricatus, Assemblus.....
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!

Ok, so some progress on the Fuel Tank today. I had bent and cut most of it up last week. This weekend I decided to start doing some practice runs with the GTAW on some small pieces. I've been around welding my whole life, fairly proficient at GMAW, FCAW, and SMAW with Steel and Stainless, and GTAW steel and SS. However, the Aluminum was always my Fathers domain. His specialty, his craft. A true expert. In his heyday, his "Stack of Dimes" was more like Robotic. So when anything Aluminum came up, he would take care of it. I normally stuck to my own kind.... This is a bit different. Now I want to do it, and well he made it look so effortless, much the same as many of the better guys on Youtube. I know better than to think "How hard can it be?", but this is a WHOLE 'nother animal! I spent the better part of the weekend practicing grinding my Tungsten...Mind you, it's .080" aluminum, open corners, so it isn't a walk in the park for even some experienced Tig guys. Also, I'm using a Dinosaur Miller Synchrowave 300. Great machine for heavy Aluminum, but not as friendly with the thin stuff as the new inverter machines with pulse and frequency selection. I'd get a few good inches, then "Bam", either dip my tip, or blow a hole. Quite frustrating to say the least. Tonight, the little dim bulb at the back of the mind began to glow. Sometimes you have to step back, and have a GOOD look in the mirror. We TEACH welding and certify welders. I'm constantly telling guys "Make sure you are comfortable", "Do you need glasses, or a cheater lens", etc. I needed to follow my own advice. I realized I really couldn't see the puddle as well as I should even with a cheater. Time for a new cheater, or regular glasses again. Second, I broke out the "Clear View" technology Miller helmet I bought a while back but never put into use. Man, what a difference in the view of the puddle! So I went ahead and tacked up the sides of the tank, and dove in. They ain't going to win any beauty contest, but they are a great deal better than the Pidgeon Sh*t I was making over the weekend! Pretty good penetration overall, don't think there will be any problem with leaks. I also took a bit of time to set up the Power Mig 350 with .035" 4043, set for "Pulse on Pulse", and ran a couple of open corners. I'm impressed. Looked just like a Tig weld. Today I stepped outside of my comfort zone, and I grew a little. It was a good day!

_________________
Dismantalus, Fabricatus, Assemblus.....
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!

It has to do with how fast the air can flow out versus how fast you pump it in at the station. Once the level in the tank rises to the bottom of the standpipe, air cannot flow out of the remaining space without going through the small hole in the standpipe that I mentioned and the tank vent (if separate from the cap). If you pump slow enough, you can completely fill the tank to the neck and the neck pipe on production cars. My wife told me about a dipstick at a station raising hell with the attendant about how his tank is a 20 gallon but he pumped a little more than that so the pumps must be wrong.

I know what you mean. I have enforced safety for 15 years yet still injure myself at home from time to time by not wearing adequate PPE.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

I just made my tank. I "cheated" and used 0.125" 3003 with my Syncrowave 200. Its a little heavy, but with the baffles welded i, it is really solid.
I use 1.00 cheaters for reading but 1.50 cheaters for welding.
I found that "name brand" glasses work a lot better than the amazon specials - i think i bought Foster Grants for around $15. I spent a lot of
getting the fit right and used lots of tacks. Im just an amateur but it came out okay - no leaks.

Got some more time in this week. Obviously this epidemic isn't how I wanted to get the time, but, hey, what the hell. Made more progress with the gas tank, using the first round for a mockup, I'm going to make a second one for the real install. Then I went to work on locating the rear hubs. Jacked the wheel up to ride height, and made a place holder for the Coilover with spherical rod ends and tubing. Rotated it to the proper orientation, and made a bracket to set the lower arm at 14*, spaced the second one at 3-15/16" per factory, which set the angle of the upper arm. Looks like I have about a half inch clearance between the od of the coilover and the half shaft. I'm using the original shock location, so if it isn't enough clearance, I can make a couple of brackets from 1/4" plate that pick up the dog bone bolts, and drop down and offset the Coilover towards the front of the car. I've seen them in C4 kits for other cars ($275) I'll repeat tomorrow for the passenger side. I also did some more tweaking on the engine bay. Engine came back another 4" or so. Still enough room for the pedals. That means that the car will have a wheelbase about 2" shorter than a C4 Corvette, with the engine 3" lower and 17" further back. Pulling the engine back gave me some insurance that the bonnet will clear the Tuned Port without cutting it or needing a scoop or blister. Something else that caught my attention today was the front control arms. I jacked the driver side up to ride height, and the control arm was just barely pointing down away from the frame. If you look at the engineering prints of the early C4, the arms point down away from the frame at a pretty good angle. I think I may have to separate the subframe, and instead of it being butted to the front cross member, it will have to be moved up and back on top of the lower crossmember. I'll have to find someone with a C4 that will let me measure the angles at ride height to be sure. Everything is only tacked or stitched at this point, so not a big deal to move it. Doing so would also have the advantage of keeping the vertical support for the upper arms inside the frame rails, and allow me to make a nice aluminum cover to hide that nasty looking subframe! I want to get this off the build table on the old C4 rims and tires to see better how she is going to look. Hopefully in the next few days.

_________________
Dismantalus, Fabricatus, Assemblus.....
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!

Got some more time in last night. Matched the passenger side suspension points to the driver side. Took a play from Yohan's build and moved the pedals back about 4" to gain a bit more foot room. I was also able fit up the OE rear swaybar in place if I decide to hook it up. I also got a jack under the front ball joint, and jacked the arm up to ride height, then took a digital level, and checked camber change over full droop to full bump. Looks like about 1.2* or so of negative camber gain from droop to bump. I also checked it from a much lower point, mimicking the the GM drawings of the '84 arms, and the numbers were pretty much the same. Shows that what I had heard about the minimal camber change on these cars is pretty accurate. It also means I don't have to move the damn subframe, just get it re-leveled and stitch it up. Now that I have the suspension issues dealt with, I can finalize my tunnel and rock and roll on bracing and welding the frame up solid.

_________________
Dismantalus, Fabricatus, Assemblus.....
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!

Got some more time in last night. Matched the passenger side suspension points to the driver side. Took a play from Yohan's build and moved the pedals back about 4" to gain a bit more foot room. I was also able fit up the OE rear swaybar in place if I decide to hook it up. I also got a jack under the front ball joint, and jacked the arm up to ride height, then took a digital level, and checked camber change over full droop to full bump. Looks like about 1.2* or so of negative camber gain from droop to bump. I also checked it from a much lower point, mimicking the the GM drawings of the '84 arms, and the numbers were pretty much the same. Shows that what I had heard about the minimal camber change on these cars is pretty accurate. It also means I don't have to move the damn subframe, just get it re-leveled and stitch it up. Now that I have the suspension issues dealt with, I can finalize my tunnel and rock and roll on bracing and welding the frame up solid.

_________________
Dismantalus, Fabricatus, Assemblus.....
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!

Last night I started making the place holders for the front coil overs. Set the drivers side at ride height, cut a piece of tubing to 17", and tacked it in. Made up the lower mount for the passenger side.
This morning, I set the passenger side to drive height, and what do you know, the 17" tube is 1" too short to attach to the chassis. I have now checked every datum point I could possibly think of. The passenger side lower arm is at 9.25* at ride height. The driver side is at 7.35* at ride height. I took measurements from the upper control arm cross shafts to ground, the lower control arm cross shafts to ground, the height from the steering arms, the lower coilover brackets, checked the cross member for level side to side, distance of control arm attaching points to under side of top of frame. Everything that I check is within 1/16" yo 1/8" of each other. I cannot for the life of me figure out why, or how, the angle of the arms are asymetric at this point. I saw the car the suspension came out of, and now front end damage. The aluminum components are fine, and there are no witness marks suggesting that the subframe was damaged or twisted in any way. Besides, if the subframe were damaged, then it should show up in some of the datum points being off. I'm stumped. I've attached pictures to highlight the discrepancies. If anyone sees something I missed, please chime in!

_________________
Dismantalus, Fabricatus, Assemblus.....
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!

Is your chassis/table/ground sitting level?

Interesting build! I had a C4 rear end in my garage that I was going to build around but then changed directions, so fun watching you put it all together.

_________________
Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52