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Boyd tank question.

5K views 8 replies 5 participants last post by  daveS53 
#1 ·
I am getting ready to order a Boyd tank.
Any advice from experience?
I plan on an external pump, carbureted, but with a return line. (Possible EFI sometime)
What about a drain plug?
A second vent to promote better fill times?

Thanks in advance
 
#2 ·
d0 it

I am getting ready to order a Boyd tank.
What about a drain plug?
A second vent to promote better fill times?
Thanks in advance
Yes and yes

You should also change the shape so it's easier to fill and easier to remove if you need to.
Make the tank shorter in height <for more fall on the fill neck.
Shorter in length< for easier removal.
Add more front to back dimension to create the total volume you want.
IF you may go EFI later also add a -8 return port and cap that until you go EFI. One of the vendors found that the EFI returns are too small which adds too much air/foam IIRC to the fuel.

I'm happy with my custom Boyd tank. I did add a drain to mine too.
DB
 
#4 ·
I have about a 3 foot long 1-1/2" diameter fill hose to my tank. I used the standard 1/4" roll-over valve, connected to a home made carbon filter as a vent. Filling the tank always resulted in a big burp of fuel, no matter how slowly it was filled. I had an extra 3/8" NPT port in the top of the tank and was able to route a 1-foot long 3/8" hose with a 1/4" NPT ball valve at the end, to a location where I could easily open it before filling the tank. That fixed the burping problem entirely. I can now fill up quickly and not have to worry about the fuel burping.

Boyd sells larger roller-over valves that may also be the answer to better venting. Just keep in mind that a roll-over valve does nothing to stop fuel splash from coming out the vent. It's got a steel ball at the bottom of a short tube and it only stops fuel flow if the car is upside down.

With a 2" fill hose, I've seen a 3/8" white poly tube inserted inside the fill hose, to serve as a vent. Don't know how well that works.
 
#5 ·
Unless you are pressing the fuel dispenser tight aginst the fill opening, the air can flow out the fill tube. I don't think an additional vent will do anything. I take my time and fill slow, I may spend 5 min filling my tank and I usually stop short since an overflow would spill into my trunk.

It takes longer to fill my Truck with the 30-gallon tank than to fill my little Boyd tank.
 
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#6 ·
My build is not at the stage that fuel is needed yet but I am now concerned a little bit about the Boyd tank now. I thought that it solved the FFR tank problem and that is why everybody switches to them. I have an efi setup and am running the tank as it comes from Boyd. Is there something I should do now before I have fuel in it and it is to late?
 
#7 · (Edited)
In-tank pumps are now considered to be the best setups for EFI, but they can be pricey. Most can also be installed with little difficulty to almost any tank. The problem with using one in a '33 is the lack of tank access.

I see that Boyd sells an in-tank pump that only requires drilling a large hole for the pump and drilling and tapping 12 10-32 holes to secure the pump. Getting those holes perpendicular to the tank might be tough.

I have an in-tank fuel pump from Tanks Inc.. It works fine, using a pressure regulating filter with return. All of the fittings are -6AN. It uses 16 10-32 screws that screw into a plate that is tack welded to the inside of the tank. The threaded plate that tanks sells is only available in steel (AFAIK), to install in steel or stainless steel tanks. Welding could be avoided by adding 2-3 countersink head screws in-between the threaded holes that mount the pump, or by drilling and tapping the tank.

In-Tank Fuel Pump Module - PA-Series

In-Tank Fuel Pump Module - PA-Series

A proper return does not need a -8 fitting size, but it should have a tube that deposits the fuel close to the bottom of the tank. This would be no different than a typical fuel pickup tube.

Fuel Tank Pickup Tube

Personally, I would not want a fill cap in the trunk. I had one in the trunk and removed it in favor of a deck-mounted filler.

I also disagree about the value of an added vent. It fixed my fuel burping problem immediately so I no longer have to baby the fuel filler lever. An internal vent tube inside the 2" fill hose might do the same thing. My 1-1/2" hose is just too small for this solution.

Rumbles '33 build shows how he managed to add a filler hose vent. Page 11, post 118.

http://www.ffcars.com/forums/120-fa...sored-e-t-wheels/238841-rumbles-build-11.html
 
#8 ·
Here's my future plan for a tank vent, now that I have eliminated the fuel burping with a 3/8" hose off the top of the tank, that has a ball valve to open only while fueling.

I'm going to drill and tap 1/4" pipe threads into the side of my filler neck, just below the deck surface. A 3/8" hose barb fitting will be screwed into the side of the neck and a 3/8" hose routed from the top of the tank to the new fitting.

When the tank is being filled, air will then vent out above the fuel nozzle and I'll have no risk of the fuel coming out of the vent tube, since it will be mounted far above the top of the tank. I'll no longer have to reach in and open a ball valve to vent the tank.

Unfortunately, I'll have to remove the driver's seat and the rear upholstery panel to remove the fuel filler cap.
 
#9 · (Edited)
I got ambitious today and reworked my gas tank vent. It required a lot of time on my knees and I'm getting a knee joint replaced next Tuesday, so I decided to get the job done now.

I removed the filler cap, drilled and tapped 1/4" pipe threads as high up on the neck as I could, installed a 3/8" hose barb fitting and routed a new hose to the top of the gas tank. It took about 3 hours, because I had to remove the driver's seat and both seat belt retractable straps, the upholstery panel behind the seats and the opposing panel in the trunk, plus the false trunk floor. It all went smooth and after it was done, I headed straight to the gas station to try it out. I topped off the tank with 5 gallons pumped in at full flow with no burping.

The length of ABS pipe in the vise may look strange, but it served nicely as a third hand, while I drilled and tapped the filler cap neck. I didn't want to clamp the filler neck in the vise.

The form-a-gasket non-hardening sealer is fuel resistant and works well to insure that neither fuel or water gets inside the car. This is not a place to use silicone sealer.







 
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