The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board > 67-72 Chevrolet & GMC Pickups Projects and Builds

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 11-24-2012, 12:43 PM   #1
TchncnDen
Registered User
 
Join Date: Apr 2012
Location: Denver, CO
Posts: 232
In tank fuel pump: How to

Mods: I wasn't sure where to put this so feel free to move.

This is how I put an electric fuel pump in a blazer tank for use in my 71 pickup, but the method should work for just about anything with a gas tank.

For supplies you will need:
gas tank
fuel pump
4" vent cap from hardware store
3/8" threaded rod long enough to reach the bottom of tank plus a couple inches
5/16" and 3/8" steel fuel line
hose clamps
3/8" SUBMERSIBLE fuel line (regular fuel line will not work)
cork gasket material

The first thing I did was cut a hole big enough for my vent cap to fit through in the tank. I used a plasma cutter but I was working on a brand new tank. If you are using a tank that has ever had gas in it take the proper precautions before any cutting of any kind, blades make sparks too. I am not going to tell you how to prepare an old tank for cutting because I want no liability in this matter, look it up and be safe. I made my cut freehand so it looks kinda like I put a piece of cheese in the tank and had a rat gnaw the hole, if you have a big enough hole saw that would be better.

Next I used a piece of paper to trace the hole I just made and then drew a circle about 1" larger in diameter around that hole. Then I made marks for six holes big enough for #10 screws close to the inner circle. Put this template over the hole in the tank and use a center punch to mark the holes for the #10 screws and drill them out. The reason for putting them close to the edge is so you can tack them into place. My closeup pictures of this didn't turn out but you get the idea.
Attached Images
  

Last edited by TchncnDen; 11-24-2012 at 12:54 PM. Reason: forgot a part
TchncnDen is offline   Reply With Quote
Old 11-24-2012, 12:53 PM   #2
TchncnDen
Registered User
 
Join Date: Apr 2012
Location: Denver, CO
Posts: 232
Re: In tank fuel pump: How to

Now take that same template and cut a piece of sheetmetal to the outer diameter and center punch the six #10 holes and drill them out big enough for the plate to easily fit over the mounting studs. You will also need a hole for the 3/8" threaded rod, the fuel line clamps, the pump wires and the two fuel lines. I elongated the fuel line holes so the lines could sit closer to the tanks while coming out at a 90. It will take a little trial and error on where to drill these holes, I have no dimensions and you may find a better way. I tried to make use of the factory reliefs in the tank to run the fuel line.

Cut a sheet of cork gasket material to fit between the mounting plate and tank.
Attached Images
  
TchncnDen is offline   Reply With Quote
Old 11-24-2012, 01:03 PM   #3
TchncnDen
Registered User
 
Join Date: Apr 2012
Location: Denver, CO
Posts: 232
Re: In tank fuel pump: How to

Now you need to weld a little mounting tab to your threaded rod, this is so you can attach the vent cap.

I took a wild guess and decided I wanted holes in the vent cap to allow a 30 second drain time. I ended up with one 1/4" hole and one 5/16" hole on opposite sides of the cap, as low as you can get them but not on the bottom. It was a good guess because I ran out of gas before I had my gauge hooked up and I used every last drop.
Attached Images
   
TchncnDen is offline   Reply With Quote
Old 11-24-2012, 01:19 PM   #4
TchncnDen
Registered User
 
Join Date: Apr 2012
Location: Denver, CO
Posts: 232
Re: In tank fuel pump: How to

Now it's time to bolt the top plate on and start figuring out the lines. I ended up with the top plate and vent cap not being concentric so that the sump would be on a flat part in the tank. Now is also the time to set the length of the threaded rod so the sump sits flat on the bottom of the tank. The tank will sag some when it is full but by the time you need the sump it is nearly empty so just make sure it sits flat while empty.

Once that is all set start bending your lines. You want the return line to drain into the cup so make it long enough but leave about 1/2" from the bottom so that it isn't restricted. You can't see it in the picture but I have a clamp holding it to the sump. Make your supply hose long enough to reach your pump while using the least amount of very expensive submersible hose. I think it would be best to braze your lines to the top plate. My brazing experience is only slightly greater than zero, so I quickly burned a hole in the fuel line while doing so. I bent a new line and decided to just tack them into place with the mig, then I used gas tank epoxy to fill the voids.
Attached Images
    
TchncnDen is offline   Reply With Quote
Old 11-24-2012, 01:38 PM   #5
TchncnDen
Registered User
 
Join Date: Apr 2012
Location: Denver, CO
Posts: 232
Re: In tank fuel pump: How to

Now you just install the pump, put the whole assembly in the tank, install the tank, run your wires and fuel line and call it a day. Once everything is figured out trim the threaded rod flush. I ended up shimming the pump side of the tank down about 1/2" and also routed about 1/4" out of the bedwood directly over the lines so the lines and bed wouldn't hit. I probably didn't have to route the wood, but I decided it was worth the extra insurance.

I bought a new tank, 25' coils of fuel line and a walbro 255lph fuel pump off craigslist from a guy making more horsepower than the pump could deliver. Add in the submersible hose, wiring, filler hose, junkyard fuel door and filler and I have less than $400 in my complete fuel system. I tested it the hard way and it uses every last drop of gas, I don't have to worry about starvation or air lock and it is way quieter than an external pump. I hope this helps someone out.
Attached Images
     
TchncnDen is offline   Reply With Quote
Old 11-27-2012, 11:17 PM   #6
Jdubs71
Registered User
 
Jdubs71's Avatar
 
Join Date: May 2012
Location: Sanger, CA
Posts: 409
Re: In tank fuel pump: How to

I like the idea of using the rear marker as the fuel door. Any issues with the nozzle not fitting. PS nice write up by the way.
Justin
Posted via Mobile Device
Jdubs71 is offline   Reply With Quote
Old 11-27-2012, 11:54 PM   #7
TchncnDen
Registered User
 
Join Date: Apr 2012
Location: Denver, CO
Posts: 232
Re: In tank fuel pump: How to

It's a little tight getting the cap on and off but the nozzle fits fine. It actually fills faster than my 98 dakota.
TchncnDen is offline   Reply With Quote
Old 12-16-2012, 03:40 PM   #8
1970 C10 MJW
Registered User
 
1970 C10 MJW's Avatar
 
Join Date: Aug 2012
Location: Indiana
Posts: 469
Re: In tank fuel pump: How to

subd
__________________
70 C10 working on a LSx swap
4.8L MS3 edelbrock pro flo intake, pacesetter long tubes, 4l60e 2500 stall hoping the tranny holds up lol
1970 C10 MJW is offline   Reply With Quote
Old 08-01-2013, 08:53 AM   #9
TypeSL2
Registered User
 
Join Date: Jul 2013
Location: Nashville, TN
Posts: 216
Re: In tank fuel pump: How to

That is a pretty cool setup man. Thanks for sharing that. That is definitely something I am going to look into. Great write-up.

James
TypeSL2 is offline   Reply With Quote
Old 05-05-2014, 07:23 PM   #10
Low Elco
Registered User
 
Join Date: Apr 2003
Location: Indep, MO
Posts: 5,133
Re: In tank fuel pump: How to

Nice writeup! This may come in handy!
Low Elco is offline   Reply With Quote
Old 03-16-2017, 04:18 PM   #11
elf w/capital T
Registered User
 
Join Date: Feb 2011
Location: North Carolina
Posts: 932
Re: In tank fuel pump: How to

Awesome, i am debating on the tanks inc pa4 pump but this looks like fun and do able, now just gotta free up my tank before i cut! Thanks for the write up!

By chance does any one know the depth of the tank? Im at work
elf w/capital T is offline   Reply With Quote
Old 03-16-2017, 04:26 PM   #12
Devil Pup
Registered User
 
Devil Pup's Avatar
 
Join Date: Dec 2007
Location: Riverside, Ca
Posts: 366
Re: In tank fuel pump: How to

To the OP, nice set up, i might have to look into this for my FI swap

Quote:
Originally Posted by Jdubs71 View Post
I like the idea of using the rear marker as the fuel door. Any issues with the nozzle not fitting. PS nice write up by the way.
Justin
Posted via Mobile Device
Jdubs, I have the filler in the side marker as he does and in California it inst a good idea in my opinion. The boots they have at the pumps are just too big.I have to fight it to get the pump in and seated and than fight it to get it out. Im changing mine during the rebuild.
Devil Pup is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:35 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 1997-2013 67-72chevytrucks.com