Rear fuel tank install
Posted: January 19, 2009, 6:28 pm
I recently completed a rear tank install on my 63 SWB unibody and it was suggested that I post it here. So, here goes.
I assume that all 61-64's have the same frame basically and this may work on 65-66 but not sure. I am using a Tank from http://www.tanksinc.com/index.cfm It is labeled as correct for a 48-52 Chevy sedan, 16 gallons. I also ordered the universal lower straps. The top I made myself. The very rear xmember was the only one requiring modifications.
Being that I had the body off the frame at the time the install was considerebly easier but could be done body on frame.
[albumimg]4992[/albumimg]
First, I ground off the heads of the rivets on the rear most crossmember. This crossmember makes a "hump" upwards in it's stock arrangement. It was suggested that I flip it down and slide it back so that it could provide a place for license plate mounting in the future. I decided to flip it down and reverse it so I could notch the bottom for strap supports (see later in the article). The rear xmember flipped down will also provide protection for the tank in the case of a rear impact.
The crossmember can be seen here
[albumimg]4960[/albumimg]
Changing the rearmost xmember position in this manner allowed for 2 things. One, I was able to run top straps (1 1/4 18ga mild steel strips from Home Depot) between the 2 rear xmembers and the top of the tank will be level with the frame
[albumimg]4959[/albumimg]
And second it allowed me access to cut, bend and tackweld small pieces for the lower strap adjuster bolts to run through.
[albumimg]4961[/albumimg]
I got a role of door weatherstripping (also from Home Depot) to use as insullation on the straps. It is just some adhesive backed dense foam. Whether you use foam or rubber. There MUST BE some insulation between the tank and the straps or it will wear through with time. Not to mention it will be noisey.
The foam insulation can be seen here
[albumimg]4993[/albumimg]
The tank is about 8 inches deep at it's lowest point so I was able to tuck it up pretty high but you can see that it never rises above the frame rail more than 3/8 inch. Plenty of room!
[albumimg]4996[/albumimg][albumimg]4998[/albumimg]
Plus if you use a tensioning bolt like I did on the rear of the lower straps it makes removal a breeze. Also keep in mind that the suspension on my rear has already been dropped 2 inches and theres still plenty of room for exhaust or whatever.
[albumimg]4997[/albumimg][albumimg]4994[/albumimg]
Of course the tension bolts will be trimmed once everything is said and done but don't trim them too much or you won't be able to reinstall if you remove. I will probably take about 1.5 inches off each side. That will make them just slightly above the tank.
In order to fill from the side I had 2 options. either run the filler tube through the frame or on top of the frame. I decided to go through the frame because above the frame between the bed and frame would be TIGHT.
I used a 2.5 inch hole saw (again from Home Depot) and made a cut behind the rear spring perch. Because it's behind the rear perch, there is practically no load on this area from suspension or body weight. Plus it was a perfect straight shot to the filler tube mounting location.
[albumimg]5042[/albumimg]
I also chose to take a small notch out of the rear xmember for an additional 1/2 inch or so of clearance. The tube would've cleared without this modification but only by about 1/16 inch (too close for fuel line)
[albumimg]5043[/albumimg]
This is the filler pipe I came up with. The lower gold stub was supplied with the tank and the other segments are small pieces of 1.25 inch pipe from...you guessed it, Home Depot. Kind of rough at first
[albumimg]5041[/albumimg]
But with paint, and after the OK from Wilbur the tech inspector dog it came out looking pretty good
[albumimg]5044[/albumimg][albumimg]5045[/albumimg]
NOTE: I could've put the rubber hose directly on the supplied gold stub pipe and been fine. I chose to run steel through the frame for peace of mind.
At the time of writing I am finishing up the fuel door that will be installed once I get the body back on. If it looks like too much time has passed since the date of last edit...PM me and I'll get on it again. I tend to get side tracked.
I assume that all 61-64's have the same frame basically and this may work on 65-66 but not sure. I am using a Tank from http://www.tanksinc.com/index.cfm It is labeled as correct for a 48-52 Chevy sedan, 16 gallons. I also ordered the universal lower straps. The top I made myself. The very rear xmember was the only one requiring modifications.
Being that I had the body off the frame at the time the install was considerebly easier but could be done body on frame.
[albumimg]4992[/albumimg]
First, I ground off the heads of the rivets on the rear most crossmember. This crossmember makes a "hump" upwards in it's stock arrangement. It was suggested that I flip it down and slide it back so that it could provide a place for license plate mounting in the future. I decided to flip it down and reverse it so I could notch the bottom for strap supports (see later in the article). The rear xmember flipped down will also provide protection for the tank in the case of a rear impact.
The crossmember can be seen here
[albumimg]4960[/albumimg]
Changing the rearmost xmember position in this manner allowed for 2 things. One, I was able to run top straps (1 1/4 18ga mild steel strips from Home Depot) between the 2 rear xmembers and the top of the tank will be level with the frame
[albumimg]4959[/albumimg]
And second it allowed me access to cut, bend and tackweld small pieces for the lower strap adjuster bolts to run through.
[albumimg]4961[/albumimg]
I got a role of door weatherstripping (also from Home Depot) to use as insullation on the straps. It is just some adhesive backed dense foam. Whether you use foam or rubber. There MUST BE some insulation between the tank and the straps or it will wear through with time. Not to mention it will be noisey.
The foam insulation can be seen here
[albumimg]4993[/albumimg]
The tank is about 8 inches deep at it's lowest point so I was able to tuck it up pretty high but you can see that it never rises above the frame rail more than 3/8 inch. Plenty of room!
[albumimg]4996[/albumimg][albumimg]4998[/albumimg]
Plus if you use a tensioning bolt like I did on the rear of the lower straps it makes removal a breeze. Also keep in mind that the suspension on my rear has already been dropped 2 inches and theres still plenty of room for exhaust or whatever.
[albumimg]4997[/albumimg][albumimg]4994[/albumimg]
Of course the tension bolts will be trimmed once everything is said and done but don't trim them too much or you won't be able to reinstall if you remove. I will probably take about 1.5 inches off each side. That will make them just slightly above the tank.
In order to fill from the side I had 2 options. either run the filler tube through the frame or on top of the frame. I decided to go through the frame because above the frame between the bed and frame would be TIGHT.
I used a 2.5 inch hole saw (again from Home Depot) and made a cut behind the rear spring perch. Because it's behind the rear perch, there is practically no load on this area from suspension or body weight. Plus it was a perfect straight shot to the filler tube mounting location.
[albumimg]5042[/albumimg]
I also chose to take a small notch out of the rear xmember for an additional 1/2 inch or so of clearance. The tube would've cleared without this modification but only by about 1/16 inch (too close for fuel line)
[albumimg]5043[/albumimg]
This is the filler pipe I came up with. The lower gold stub was supplied with the tank and the other segments are small pieces of 1.25 inch pipe from...you guessed it, Home Depot. Kind of rough at first
[albumimg]5041[/albumimg]
But with paint, and after the OK from Wilbur the tech inspector dog it came out looking pretty good
[albumimg]5044[/albumimg][albumimg]5045[/albumimg]
NOTE: I could've put the rubber hose directly on the supplied gold stub pipe and been fine. I chose to run steel through the frame for peace of mind.
At the time of writing I am finishing up the fuel door that will be installed once I get the body back on. If it looks like too much time has passed since the date of last edit...PM me and I'll get on it again. I tend to get side tracked.