77K5. The IronMaiden...9/2 headed for Blazer Bash 20!

[76zimmer]

worked on some drawings and measurements today and came up with the floor design and opening for the tank....now to figure out the best way to support the tank..

This drawing shows the new (shaded) floor replacement, it will be 2" above the old floor level and would give ultimately about 1" of clearance between the gas filler cap, the two ports for fuel return and rollover vent, and the bottom of the floor.
I will box it down to the original floor level by the rollcage so I don't have to redo the rollcage, the tie in plate, and the connecting bar underneath the floor.
I will also run the new floor about 1-2" past the opening for the fuel tank, then box it down to the level of the old floor (see small drawing on the left)
this will allow me to capture the body mount area that needs to be reinforced and keep it at the original floorpan level...it will also allow me access to the rear seat bolt mounting.


(CLICK ON PICS FOR A LARGER VIEW)

 

[76zimmer]

This is a top view showing the mounting flanges and sizes of the tank and the opening.

 

[76zimmer]

this is a side shot of the tank and mounting....note the attachment point of the mounting flange and keep in mind the flange will be 16" long on 4 sides (see top view drawing for a better size of the flanges).....is it a stress issue?

 

[76zimmer]

a different way of mounting using the flanges but would be welded to the top of the tank instead of the sides....

 

[76zimmer]

Or would it be best to just make some straps or cradle to support instead of suspend from above?

Opinions?

 

[cybrfire]

First pic you have is the better mounting solution.

EDIT, expansion on the thought,

First pic, IF all the bolts for some impossible reason fell out, the tank wouldn't necessarily go anywhere. Secondly, the flange of aluminum can be extended down the side of the tank further than you have it drawn on there. Some rosette welds, some perimeter welds and it will hold a great deal.

Second pic, in this scenario, the bolts are in shear, which probably would never shear them but, I can imagine the bolt holes becoming ovaled over time. Also, with the aluminum flange extending off the top of the tank there is a point right there where all the weight of the tank and fuel will be focused creating a nice spot for the flange to bend and or pull at the aluminum tank sides at the perfectly wrong angle.

Make sense?

 

[76zimmer]

First pic you have is the better mounting solution.

this one?

As the first two drawings are just different angles of the same design, but the first 3 use this same mounting principal:

 

[76zimmer]

First pic you have is the better mounting solution.

EDIT, expansion on the thought,

First pic, IF all the bolts for some impossible reason fell out, the tank wouldn't necessarily go anywhere. Secondly, the flange of aluminum can be extended down the side of the tank further than you have it drawn on there. Some rosette welds, some perimeter welds and it will hold a great deal.

Second pic, in this scenario, the bolts are in shear, which probably would never shear them but, I can imagine the bolt holes becoming ovaled over time. Also, with the aluminum flange extending off the top of the tank there is a point right there where all the weight of the tank and fuel will be focused creating a nice spot for the flange to bend and or pull at the aluminum tank sides at the perfectly wrong angle.

Make sense?

Yes, and an updated drawing coming tomorrow!
New plans yet again! thx man!

 

[blazinzuk]

I don't like any type of mounting flange on the gas tank prefer to have it strapped in. Most if not all types of racing require some sort of strap system. The forces on a hard roll can be pretty huge, moreso with a full tank. I say do some type of strap system. While in all reality you will probably be fine the strap system seems to be generally accepted as the better way

 

[chulisohombre]

I like the strap idea myself. Maybe it's because that's what I'm used to and oems have used it for a hundred years but it seems like the easiest and safest way. I don't like the idea of it bolted solid to the bed floor. Something similar to stock would be easier but nothing on your truck seems to go that rought. Lol. With the top Plate floor piece it would be cool to use it as a lift point should the tank need to come out for some reason. Could pull the whole thing with a small eyelet and chain from the cage if need be. Just throwing stuff out thère but in the end you will figure something cool to make it work.

 

[woodchk502]

I like the strap idea as well. Maybe to the skid plate so you could drop it out the bottom as a 1pc with a floor jack. Or like chulisohombre suggested you could use the cage to lower it.


Jim

 

[ryoken]

Dave, however you end up mounting it, keep in mind it's vital to gusset the mounting tabs welded to the tank.. pieces of angle, etc, bend and stress.. small triangle gussets at the ends of the tabs increase the strength tenfold..

 

[76zimmer]

Yes, and an updated drawing coming tomorrow!
New plans yet again! thx man!

stay tuned for this brainstorming session of an idea.
It will allow the tank to be mounted separate of the skid, which seems like a good idea if the skid takes a hard hit, the tank mounting wouldn't be affected, it will allow a solid floor with the only gas tank filler door being bolted to it, and perhaps that could be flush mounted.

I don't like any type of mounting flange on the gas tank prefer to have it strapped in. Most if not all types of racing require some sort of strap system. The forces on a hard roll can be pretty huge, moreso with a full tank. I say do some type of strap system. While in all reality you will probably be fine the strap system seems to be generally accepted as the better way

I like the strap idea myself. Maybe it's because that's what I'm used to and oems have used it for a hundred years but it seems like the easiest and safest way. I don't like the idea of it bolted solid to the bed floor. Something similar to stock would be easier but nothing on your truck seems to go that rought. Lol. With the top Plate floor piece it would be cool to use it as a lift point should the tank need to come out for some reason. Could pull the whole thing with a small eyelet and chain from the cage if need be. Just throwing stuff out thère but in the end you will figure something cool to make it work.

I like the strap idea as well. Maybe to the skid plate so you could drop it out the bottom as a 1pc with a floor jack. Or like chulisohombre suggested you could use the cage to lower it.


Jim

Kert and I discussed the straps as well, but with 16" of mounting flange on each wall, and suspended from the floor he's sure it will be stout! We will be making a plasma cut floor section as well.

Dave, however you end up mounting it, keep in mind it's vital to gusset the mounting tabs welded to the tank.. pieces of angle, etc, bend and stress.. small triangle gussets at the ends of the tabs increase the strength tenfold..

Absolutely Paul....Kert brought this to my attention as well. He pretty much said the same thing as you have here!

 

[ryoken]

that's one I learned from boat tanks... 150 to 300 gal tanks are weighty when full...

 

[76zimmer]

I can imagine they are!....I figure a bit over 200 full for this one....~29-30 gal.

 

[ryoken]

how far above the floor is that?

i was gonna say, since your already rasing the floor, might as well go a couple more inches and see if you can get like 40 in there....

I'm sooooo stoked on the idea of the 55 gal in Mutt's tubebed..

 

[76zimmer]

the new floor will be 2" above the level of the old floor, that will give me room for this new tank and about an inch clearance between the filler cap and hoses for the vent and return lines on top. It should give me 1/2 to 1" of clearance between the tank and the skid.

I will put a considerably larger tank in the bed of my CC as well....those 2 20gal side saddle tanks are a PITA to fill (and it happens quite often too)

 

[76zimmer]

updated mounting drawing:

With this method the floor will be solid from seats to fenderwells to rear tailpan.
Only opening will be a 6" sq. fuel filler door recessed into the floor.

 

[Deuling]

Hey dave...


So we gonna dive into this when we get back from kerts???


I got monday and tuesday off work that week....

So if we came back sunday night... we could fab all day monday etc if you got no plans...


I can supply beers

 

[76zimmer]

Don't know Adam, I have to work Tuesday, and my calendar gets full quickly, but its open right now, maybe I'll block it out for dedicated Maiden work!
I'll keep it in mind fo sho!