New style fuel tank mounting - suggestions?

[ben1272]

Sorry if this has been covered before....I did do some searching and did not come up with anything. Please, if this is a repeat, help me find the info.!

My new style tank has no mounting tabs of any kind, and the instructions only cover the old style tank. Can anyone shed some light on this for me?

Also, my new tank seems to be 'blown up', as in like a balloon. Sides are popped outwards, like maybe it was pressure tested after fab to check for leaks? Maybe heat deformation from welding? Anyone else have this? I does not fit great against the frame as a result. Also, it is too wide to slip down between the interior side panels (if they are in place). Since I want to be able to remove the tank, it either needs to get narrower (not sure how) or I need to come up with some sort of segmented side interior aluminum panels so that they can be removed in order to get tank out.

Any help or suggestions are appreciated. I have sent an inquiry in to Dan Golub at FFR as well, and will report back what he has to say on the matter!

Hope everyone has a nice new year!

-Ben

[Hindsight]

Hi Ben.

I went through all that with the new tank too. FFR says you don't need mounting tabs; they say the new firewall will hold the tank in. I didn't like that so I welded some L-brackets to the top of my tank and bolted it to the frame with rivnuts.
http://i.imgur.com/I8giJ1Ll.jpg (http://imgur.com/I8giJ1L)

I also added a "burp" vent line to the filler neck so the nozzle won't click off while filling (before it is actually full), and to keep fuel from splashing out. You can see details in my build thread for that.

As far as ballooning and the tank not fitting.... mine has a LITTLE bit of bulge to it. Is it extremely noticeable to you or are you mostly noticing it because you are wondering why the tank might be too wide? If it isn't THAT noticeable or severe, it might be fine (matching mine). My tank fits in but it's tough. You have to drop it in at a very specific angle and then shift it a bit this way and that way. I can't remember exactly what is involved but I R&Rd mine a few times during the welding/fitting/painting process. It was tough every time but it always went in. I think I had to tip it back a bit and one side always had to go down a couple inches before the other would go. Don't push on it or it can get wedged in there and be very tough to get out.

[ben1272]

Seems like a bad idea to not securely attach the tank to the chassis.....100+ pounds of gasoline is a lot to move forward into aluminum panels in accident conditions. Speaking of which, is that the reason the floor of the tank compartment has the slots all the way around, for gas drainage/vapor ventilation?

Hindsight, I like your tabs, but I am not a great welder. Do you have any tabs at the sides or bottom too? I remember reading about someone who was planning to make straps from the unused seat belts. I don't remember who it was, but I wonder if they had success with these or another strap solution? Maybe metal gas tank straps could be made to work?

I don't mind winging it, but the gas tank is one of those parts of the build that makes me nervous....especially given it is in the passenger compartment to start with! Seems like it should be very securely anchored and there should be a FFR approved and recommended factory approach to this. Maybe FFR is working on new instructions....maybe FFR will post solution here?

[Hindsight]

I'm not sure if FFR regularly monitors the forums so if you are looking for a solution, I would either do it yourself or call them on the phone. E-mail is not usually the best way to reach them.

Back to the tank... if it's never had fuel in it, you should be able to take it to a welder and have brackets welded on for CHEAP. I literally bought angle brackets in the Home Depot hardware section. Just put the tank in the car, set the brackets to where they line up with the X-frame as shown in my pic above, then trace their outline on the tank. Take the tank and brackets to a muffler shop or any shop that can weld. Before I got a welder, I would pay a guy at an independent shop down the street with a bottle of whisky for doing small welding stuff like that for me. If you have to pay someone, something like that would cost $100 or less (only reason it should be $100 is if you can't find someone who won't hit you with a minimum hourly rate - independent shops are better because of this kind of thing).

Aside from the top, the bottom is held it quite well by the firewall. The bottom of the firewall turns 90 degrees and wedges into the gap between the tank and frame. I feel it's pretty secure... secure enough for me anyway.

[Bob_n_Cincy]

Summit has some straps made to hold gas tanks.

http://www.summitracing.com/search/part-type/fuel-tank-mounting-straps-and-adapters/universal/yes?N=4294914265%2B4294951518&SortBy=Default&SortOrder=Ascending&tw=strap&sw=Fuel%20Tank%20Mounting%20Straps%20and%20Adapter s

The slots in the floor are in case of a gas tank leaks, to allow the gas to run out of the car.
Also to let any water in the cockpit to drain out. We drilled eight 1/4" hole in the floor under the seat for that reason.
Bob

[ben1272]

Thanks for the link Bob. I will check them out. I like the idea of strapping in the tank, as it seems to be the production solution car manufacturers tend to use.

My tank has not had gas in it (that I know of!) and so should not pose any problems for welding. I have a mig and tig torch, just my welds are sometimes awesome and sometimes not so awesome! :) I may give one a try and if it goes smoothly do more.

Anyone decided to slosh the tank with a tank sealer? I think I would only do this if I experience leaking.

If anyone else has strapped or welded, etc., their new style tank, I would love to see more ideas! I will post pictures of where I end up.

Thanks!

-Ben

[Sgt.Gator]

Are ya'll saying the tank is not bolted down? What happens in a roll over?

[ben1272]

Are ya'll saying the tank is not bolted down? What happens in a roll over?

Yes, not bolted down according to Dan at FFR. I asked how it is attached as the new most current fuel tank is not shown in the latest revision of the instruction manual. Was told that the firewall is the only thing holding the fuel tank in place. Firewall is ~0.125" aluminum sheet bolted to the frame, but it is not a tight fit around the tank....especially the top where the lines and sender plumbing are mounted. In a roll over I guess it will move until it contacts the bend in the firewall. It might be contained, but it doesn't sound like a good idea to me.

I'm still contemplating what to do and will show you what I end up with. Hindsight's build shows his good suggestion to have angle brackets welded onto the tank in line with chassis square tubes....bolt it down. I'm going to investigate strap options as well. Some are getting tanks that mount forward under hood.......might not be a bad idea, but still needs some sort of secure mounting technique I would think.

[redfogo]

Weld on some tabs and bolt to the frame best bet.

[Dave's Dream]

I installed a piece of 1/8 inch rubber under the tank and all the way to the front of the fire wall under the leading-edge To keep it from rubbing on the floor. I'm also going to cut some 1/8" steel and make two hold downs which I will attach to the bar behind the tank with rivnuts. I plan to also glue 1/8" rubber to the bottom of the hold down brackets to avoid metatarsal to metal rubbing.

[ben1272]

Dan at FFR replied to me today and told me that the GTM uses the same mounting technique as the new 818 tank. We might learn something from the GTM guys. I am going to have a look.