# modified mk2 fuel pump box, DIY for fitting a walbro in there



## smugfree3 (Feb 20, 2006)

i just couldnt let go of the idea of using the stock fuel box as a surge tank of sorts, and getting the side benefit of submerging my fuel pump for noise suppression. heres what i did:
first i removed the mounting ring from the stock fuel pump. in order to fit the walbro through it material has to be removed from the inner diameter. i used a hole saw for this.

the other fitment issue arises when you realize that the filter basket has to be shortened like so:

using a plastic cap i had, i drilled out the middle of the cap to fit the screw on aluminum fitting i have for the intake side. then fit that the the inside diameter of the filter basket. all assembly was done with epoxy and then covered with por-15.
you end up with this:


the mounting ring was then jb welded to pump body and painted on the outward side. 
finished assembly with filter screwed on:

you have to find a new o-ring to fit between the pump body and box, but then you just screw it in!
final product:

and the motor it will help support:


----------



## smugfree3 (Feb 20, 2006)

anybody see any problems with this i might not have thought of?


----------



## boost_addict (Dec 4, 2009)

its pretty easy.. does it tune on? 

do you have a fuel pressure gauge? those would be two good signs if you havent thought of anyhting


----------



## bonesaw (Aug 8, 2004)

I would be worried about the jbweld. Will gas deteriorate it?


----------



## Daskoupe (Oct 9, 2006)

smugfree3 said:


> anybody see any problems with this i might not have thought of?


 never seen a epoxy stand up to gasoline 
other then that i like!


----------



## sdezego (Apr 23, 2004)

I have used JB weld for a lot of things, and a few times repairing gas tanks on say plastic Tractor and lawn mower gas tanks, but would never "personally" use it on my car other than to get home in a pinch.

Just a thought.


----------



## smugfree3 (Feb 20, 2006)

soooo. as the OP for this thread. im back to officaially pronounce it a FAILURE. i submerged the assembly in gasoline for a week and eventually the JB weld gave way. I was not suprised by this, what i was suprised by was how easily the por15 that i coated everything with gave way. just peeled right off. i thought that por15 was supposed to stand up to gasoline and other fuels??

anyway, my only major losses were the old walbro pump, and the time to find a new o-ring. o well, live and learn, and dont do this mod!


----------



## root beer (Jun 22, 2004)

Ever heard of 3m 8115? I have that holding a vent fitting on my valve cover at the moment. It's not gasoline that it's exposed to, but that may hold.


----------



## sdezego (Apr 23, 2004)

Gasoline does not affect JB weld providing it is not OLD, is mixed right and Cured Right. It really takes days to cure properly. Also, adhesion to the plastics is the real problem. That EPDM has wax in the pastic (it's just how it's made). So, it is miserable to repair properly, but it can be done.

All in all, it could possibly have worked, but as I mentioned above. this is one thing not to screw with IMO.

Thanks for posting back even though it failed.


----------



## smugfree3 (Feb 20, 2006)

was not aware of that plastics wax thing. probably wouldnt have attempted knowing that.

as far as trying other adhesive epoxies: im not going to throw good money after bad on exotic glues.
at this point, im going to look into going with one of those aeromotive intank "stealth" pumps and eliminating the box completely.


----------

