Anyone make auto gas tanks?

Tue, 31 Aug 2021 15:35:42 GMT

go to see Welding Machine for Anyone make auto gas tanks?

Curious to see what others have done in fabing gas tanks and what materials they have used to make one.  I have a car with a small 14 gallon tank that I would like to make a new tank for it to put it closer to 20 gallons.  Is it feasible to use aluminum for the tank on a daily driver as it wont spark and would have more flexibility in an accident or should it be stainless steel or should I consider coating the tank in something to add additional strength and protection like say two layers of carbon fiber or a plastic coating?Welding Supervisor Department of Corrections.
Reply:I know there are lots of other guys here who probably have made fuel cells too so don't catch me sounding like I think I am authority number one, however...I would like to know what kind of car this is.  Generally a production car that comes with a 14 gallon tank should have a 14 gallon tank.  There are a lot of things to consider.  Space is one primary concern.  Like I saidm it depends on the vehicle, but modern passenger vehicles are usually not easily adapted to accommodate larger fuel cells.  If it was built after '96, whatever it is, it has a sophisticated evap system that is programmed to perform vapor loss calculations based on a specific fuel quantity.  If the volume of the tank is changed without software considerations, at the very least you will get a check engine light.  Something to consider if they have emissions inspections where you live.  It is doable, but you need a thorough understanding of the emissions control characteristics of your particular vehicle in order to do it properly.  Vapor controls aside, another thing to consider is the fuel pump/level sender unit.  If this vehicle was built after '02 or so, it may not use the plain ole resistor based sending unit.  Most modern vehicles use a resistive multiplex based sender that reports to a module/ fuel control computer.  Based on the resistance of the circuit, the module will interpret and distribute that information all over the place including the PCM and finally, to an instrument panel cluster module which will display your fuel level.  And on and on and on.That being said, stainless is nice, 14 gauge or better if it's going to be polished.
Reply:Its a vw jetta wagon production year of 2001.  Space wise I am going to have to do some work to the rear floor plan where the spare sits due to previous damage from an accident.  As for the software change that won't be a problem as I can get my hands on the software and the hardware to do the adjustment and a vw master tech fall back on should I have a problem.  Height of the tank would stay the same but width would be expanded within reason to allow for greater capacity. As for the spare I had thought of moving the stowage location more towards the rear bumper or bringing it up and building a bracket to secure it in place standing on end and reduce the stowage area and use it for something else.Welding Supervisor Department of Corrections.
Reply:Well if you don't have to worry about inspections and arent concerned about the check engine light I say go for it.  Keep us updated, I would like to see how it turns out
Reply:Being in a shipyard, ask some people about free surface liquids... compartments that are 1/2 flooded are more damaging to a ship than those that are completely flooded. The action of the liquid in the compartment as it sloshes from side to side acts like a batttering ram on the walls. Think about sloshing water back and forth as a kid in the tub. Didn't take long to drag you all over the tub once the liquid got moving. It might not make that big of a deal with a small tank, but it does as the tanks get larger and  especially wider. You will want to think about putting some sort of baffle system in place to limit the ability on the liquid to easily slosh..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Molded plastics just like what is in it is the material to use.Keep all the parts you plan on taking off so you can put them back on when you sell it?I find it interesting how us mechanically inclined guys are always re-thinking the team of engineers who make a living on designing things we buy.
Reply:To stop the sloshing you can install foam in the tank just like fuel cells for race cars......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I had planned on internal baffles to counteract the sloshing.  Engineers don't always make the best design decisions when it comes to say a car or truck.  Two vehicles that I've had are good examples of this when it came time to change spark plugs.  I had an 86 fiero v6 and have a 96 grand caravan v6, both are easy on the front plugs and the drivers side rear plug but the passenger and the middle rear plug present the biggest issues and on the caravan you have to remove the alternator to get to the both and even then the middle requires you enduring pain unless you pull the throttle body and intake manifold to do it easily.I'll find out what state requirements and dot requirements are when it comes to fuel tanks and as for resale I'm not worried considering that the car is part of a niche performance market and I've seen them sell with some horrible mod work.  I wont have to worry about a check engine light, the hardware and software to make changes to the computers in the car are readily available ( vagcom ) and I do have a vw master tech I can always call on if need be.Welding Supervisor Department of Corrections.
Reply:The vag is a good tool, but alone is not going to be enough to recalibrate the emissions values.  I think that system uses a leak detection pump, or a system similar to the NVLD?  I am not a VW specialist, but I am an L1 cert Master.  Generally in order to change that software need a custom calibration from the manufacturer, unless you intend to use a stand alone engine management system in which case those capabilities are available in the aftermarket.  On some systems though it wouldnt be an issue...  The evap system will be certified up to a certain amount of fuel which is usually far greater than the capacity of the cell.  If you need any specific service information let me know and I will send it to you.  Good luck.
Reply:Go ahead and make it out of steel or AL. My tank is steel on my old truck, and plastic on my new truck.I doubt you will have much sloshing problem, with or without a baffle.The diesel tank in the bed of my truck is 5 feet long and has one baffle in it.