Pirate 4x4 banner

1 - 8 of 8 Posts

·
Registered
Joined
·
692 Posts
Discussion Starter #1
I'm going to change my gas tank with a 18g one. I'm going to mount it between the frame rails. My ? is how close to the exhaust would you consider safe? I want it low as possible.
Thanks
steve
 

·
Registered
Joined
·
27,625 Posts
As long as the end of the pipe is not pointoing towards the tank, you will be fine. I ran mine pointing towads the tank, but about 10" away for a while. The heat would build up and vapor lock the tank after about 150 miles of continuous driving. Removed the cap, let it breathe and kept going. I soon re-routed the exhaust to point down, and the problem disappeared
 

·
Registered
Joined
·
398 Posts
overeasy said:
I'm going to change my gas tank with a 18g one. I'm going to mount it between the frame rails. My ? is how close to the exhaust would you consider safe? I want it low as possible.
Thanks
steve
I'm considering options for doing something similar. I've got an old short box with the 12 gallon tank and I'm looking to add a second 18 gallon tank lengthwise at the back of the truck. I've spent copious amonts of time under the truck measuring and planning, heres my two bits on options:

Option 1: mount the 18g tank sideways between the frame rails behind the rear axle. Advantages, not many. Disadvatages: 1. need to remove the spare tire crossmember and make a new one. 2. the 18g tank is about 35.5" in length, and the frame rail width is 36.5", it'll be close. 3. Fuel tank hangs down way too far, look ugly, and succeptable to damage. 3. Exhaust issues, leaves no / very little room at the back of the truck for the tailpipe.

Option 2: custom build a fuel cell to mount it sideways behind the rear axle. Advantages, 1. can customize the design so it fits exactly the way you want, 2. a steel tank shouldn't be hard to make at home using parts from a junk toy tank (sender, sender ring, spout etc...). Disadvantages: 1. liability issues (legal etc...) gotta think of these things. 2. Time consuming - may need access to a metal box brake.

Option 3: mount the auxiliary tank (a second 12 or 18 g tank) at the same location at the opposite side of the frame. Advantages: 1. can use a stock fuel tank, 2. garunteed to fit (same location as stock 12g tank, just the opposite side of the frame). 3. will increase your (my) capacity to 24 gallons. Disadvantages: 1. exhaust will need to be re-routed to run along the middle of the truck instead of along the LH side. 2. Aux tank filler faces the wrong way, or aux tank fuel filler on opposite side of the stock filler.

Theres other options, but these are the three I'm considering. My motivation is that I'm running a gas guzzling V6, and I've already replaced the rear three crossmembers (e-brake mount, shock bar, spare tire carrier xmembers). The new custom crossmembers were made keeping option #1 in mind, but I'm probably going to go with option #3. I've removed the exhaust, and placed a second tank at the same location as the stock tank on the opposite side (obviously) and it looks great: looks "factory", looks proportioned ....

Option #3 gives me 2 choices for exhaust. Either mount the cat, muffler and tailpipe all before the gas tanks, or route the exhaust down the middle of the truck to the back of the truck.
 

·
Registered
Joined
·
692 Posts
Discussion Starter #5
thanks for the input. After doing some measuring and thinking I think that I have a plan.
I'm going to mount the tank between the rails right infront of the shock crossmember. This will leave room for my tool box between the cab and tank. If I will shorten my exhaust by 7in and run a down pipe i will be in the clear.
Thanks again
 

·
Registered
Joined
·
398 Posts
Thats not an option for me, I still run the factory box with only a 3" body lift. Are you doing that with the factory box?? Those 18g tanks are pretty deep tanks. You know I'm amazed at the lack of room in these old trucks. I've got an 81 short box, and trying to find room for an auxiliary tank and a second battery is not easy.
 

·
Premium Member
Joined
·
3,098 Posts
dkc1657 said:
Thats not an option for me, I still run the factory box with only a 3" body lift. Are you doing that with the factory box?? Those 18g tanks are pretty deep tanks. You know I'm amazed at the lack of room in these old trucks. I've got an 81 short box, and trying to find room for an auxiliary tank and a second battery is not easy.
I did the 2nd stock tank on opposite side in an 82 ran dual exhaust between the tanks(very close tolerances) I got some stick on heat shield from summit racing to put on the tank and never had a problem. I now have an 85 runner and am going to do the same thing.As far as the filler neck goes you can either install a y in your existing filler neck and fill both tanks from the stock location a muffler shop can fab one up cheap. Or i turned the tank 180 deg and installed another neck thriough the passsenger side using a filler neck from a mid 70's ford truck
 
1 - 8 of 8 Posts
Top