Tag Archives: gas tank

Designing gas tanks instead of sleeping

Just because I can’t get words out because brain not working right doesn’t mean I stop thinking. The exact opposite happens.

I was trying to come up with a frame that would put me on the driver’s side of the car and still be stiff and that I could fit inside the body without chopping the body into little pieces and hanging a couple of hundred dzus fittings on the frame to attach the body. Physically can’t be done. So I’m back to sitting in the center of the car and the gas tank is now sitting on either side of the frame instead of the passenger side of the interior. The fun part is now I have to design a pair of fuel tanks that literally have no parallel sides and figure out how much gas (E85) I can carry between them.

First things first I measured the body to find out what space I had to work with. The major design constraint is the sides of the tank are going to be flat pieces of steel for ease of construction, so where the curves in the body make that impossible defines the volume of the tank. First constraint is where the back of the body starts to curve up from the floor, which defines the length, 41 inches from the inside of the firewall. Second constraint is being able to slide the tanks in from the top without removing anything, so the tanks have to clear the dash and the top flanges of the body and the bottom of the dash is 10.5″ from the inside of the firewall, leaving 30.5″ as the length of the tanks. Measuring the inside of the body at the floor gave me a width of 33″ at the front and 34″ at the back. Measuring the same locations at the body top flange gave me 37″ at the front and 44″ at the back, and a depth of 19″ inside the body flanges. Now not all of this volume will be available for fuel storage, I’m going to occupy a large chunk of it, 27″ down the center front to back.

This leaves us with two methods to determine the available volume, find the total volume and subtract the volume taken up by the frame around the driver, or remove the space taken up by the frame around the driver from the measurements and calculate the space left over. The easy part is the volume occupied by the frame around the driver 27″ wide by 30.5″ long by 19″ deep, or 15646.5 in3. The volume around that is a bit trickier to calculate because the space is a trapezoidal polyhedron, and the volume is the average area of the top and bottom times the depth. The quick way to calculate the average area of the top and bottom was to average the top and bottom widths on both ends, by adding them up and dividing by the number of measurements (4) and multiplying by the length (30.5) and then the depth (19) to determine the total volume. Subtracting the volume occupied by the driver and frame leaves 25.4 gallons for fuel. Which is not enough to get across the E85 barrens of west Texas and NM at the projected fuel economy for the vehicle. That means I need to make the tanks bigger or find room for another tank. Now one way I can make the tanks bigger is taking less space for the frame (and me) but it is late and I’m getting tired and unmedicated brain is not thinking good and wants to sleep.

Weather doesn’t stop to enquire about your plans before happening

Well, plans were to wrap my workout around getting my toes done down the street, but the weather has other ideas. There has been a line of thundershowers going over since shortly after noon, when I got to sleep about 0600 after putting the previous blog post to bed about 0430. That post took extra long because I would write a little bit, go crawl around in the bucket body for a while, run some numbers on the calculator, crawl around the body again, run some more numbers on the calculator, write a bit, rinse and repeat. I spent about 3 times as much time with a tape measure inside the body as I did sitting at the keyboard. And I still need to get my toes done, the nails are getting a bit on the long side, while it is still raining with occasional lightning and thunder over Casa de El Poeta preventing my walk.

On the TGS2, the mind kept going after the post was put to bed. I considered saddle tanks as well as wrap-around tanks with luggage space on top of the tank. I genuinely think the best option would be putting the Jaz Products 892-032-01 32 gallon bare cell on edge so that it would be 17″ tall, 14″ wide, and 33″ across, behind the seat and using the space beside the seat for carrying things. Unfortunately nobody I have contacted sells them, so I might have to get it directly from Jaz, which makes the price a mystery. But it is possible to interpolate a price by comparing the costs of bare cells that I can get to the costs with cap and fittings for the same size cell, then applying that difference to the 32 gallon cell with cap and fittings. I think I’m looking at $143 plus shipping. Compared to a custom tank that’s cheap. I would still need to fabricate a firewall and fuel filler, but that would be true for any tank inside the bucket body. Jaz even makes a fuel gauge sending unit to fit this configuration.

On the bike-riding front, I’m still not riding. I do the PT that is supposed to make my neck more flexible but all it seems to be doing is keeping me from getting any worse. It doesn’t hurt to hold my head back or turn to the right, it just doesn’t go back or to the right. And I’m still getting the pain and tingling in my neck and shoulder, especially after I do my exercises. It’s almost like they never took Chris Christie off of my neck, except I have a little more range of motion especially tilting my head back. I still notice it there, and the improvement without a useless lump of fat on my neck. Every few days I check the tires on the bikes to see if they need pumping and once in a while I pump them up.

And now I think I’ll have dessert and a big cup of covefefe (CO-vay-Fay-fay). If Trump can make up words, I can make up the pronunciations.

Well, dang, that doesn’t look like it will work

Two posts ago I speculated on moving the seat forward and putting the gas tank behind the seat. Well without making a custom tank or severely cutting the body, or both it won’t work. I just spent an hour climbing in and out of the bare body with the steering wheel. If I put the steering wheel inside the passenger compartment on the normal side of the dashboard even with the steering wheel in my chest there’s no room for a commercial fuel cell between my butt and the back of the car, except the 3 gallon tank , which would be great for racing, but pretty crappy for driving to and from the races. Especially with E85 which isn’t common. There is room for a big tank behind the driver’s seat, but it would have to be built custom for the space. I roughly estimated that a 30 gallon tank would fit with room to spare. If I got really crazy it would be over 40 gallons, but that would require basically making the inside of the body part of the gas tank, which like I wrote, would be really crazy.

Another alternative is to make a race-car like cockpit like this Lotus 49.Run that through the cowl.
Basically the cowl would be cut away where the windshield is on the Lotus in the picture, and my head will be just back of the original location of the dash. There’s lots of room to play with out front once the gas tank(s) is(are) gone, but almost none behind the body because of the engine and its systems. The bad part of this would be my feet would be right up against the radiator. The good part would be there would be room for a 32 gallon fuel cell behind me which would mean 700 miles between highway fill ups with some cushion for crossing Wyoming or west TX running E85. How often I would be doing that is unknown. The only thing I could think of would be the Goodguys Shootout for the year-end champion in autocross held in AZ.

Well I have about run out of words but not ideas which continue to run through my brain but not in a complete enough form that I can post them to this blog.

I am disapoint

My book finally got here yesterday. Hundreds of pages about fuel injection… for other kinds of car than the donor vehicle for the Thunderbolt Grease Slapper 2. For the make of the donor vehicle it had 3 pages, none of which applied to the year my car was made. So basically I spent $9 and a week of waiting for some interesting light reading and a bunch of stuff I already had elsewhere (on my computer).

I think the local library will be getting a donation.

Something I have been looking at very hard lately is the Holley HydraMat fuel pickup and pre-filter for fuel injection systems. What it amounts to is my car will never run out of gas as long as there is gas still in the tank. Also the pre-filter on the donor vehicle is basically a screen to keep large debris out of the pump, while the latest permutation of the HydraMat is a 30 micron filter that is way better than the 100 micron post-filter on the donor vehicle. So in theory I could install a HydraMat and just plumb from the pump directly to the injectors without additional filtration. I won’t of course, because the pump could break down sending junk down the line to the injectors, but I could if all I was concerned about was the gas in the tank. Now there is the competing parameters of maximum size to allow minimum fuel for racing and minimum cost. The cheapest one is the 8″ X 3″ that for this application would mean I could get maximum fuel endurance on the highway between fill ups. If I was running a tiny tank like a 3 gallon this would make sense. Even the 10 gallon tank could use this, but for anything larger than that it doesn’t make sense. For the larger tanks the mat acts as an extended pickup to allow racing with just enough gas for the course, so it has to be large enough to catch most of the fuel slosh. The largest mat that fits the tank I have selected is the 24″ X 15″, and the cheapest that will work is the 15″ cross. How this is good is I can use a large gas tank/fuel cell for getting there, offload almost all the gas to another container when I get to the race and only have enough gas to complete the run in the car while I race, further reducing the racing weight of the car without the bother and expense of multiple tanks/cells and support systems, or finding a place to put them.

On other parts I just found out the smallest adult-length seat I can buy is gonna be too big for my backside. I think I mentioned a long time ago I did some width measurements to see about buying a streamlined shell for the Stratus and basically the only way I would fit would be removing an arm or two to make my shoulders narrower. Well I also measured my butt width, and to fit the 14.5″ wide seat on my build list I’m going to have to fill 3/4” on either side of my butt with firm foam of some kind. I think maybe the seat insert kit will fill the gap? It may have to because smaller seats are pricy and will still need the insert kit for things like back support. Although it would be nice to not have to buy the insert kit, the fact that selling the car will become necessary at some time means a removable insert to fit me can be removed for a prospective buyer to see if he or she fits. Otherwise a new seat at $300-500 for a home-built car could be a deal-breaker. I know the seat I had in my last car was too tight for most people but gave me a lot of wiggle room on long trips.

And it’s getting late and I still need to take my walk so I’ll see you later dudes.