Aux Fuel switching valve - where to install ? (1 Viewer)

[ErikinSC]

(c) Mount an electric switching valve mid way between both tanks (a good location would be on or near the rear tubular shock mounting crossmember).

Jim suggested this, and it seems like an ideal, out of the place location.

However - @alkarich installed his here :

and @bsevans installed one here:

Suggestions from others? Considering the Pollack 6-port on the passenger side frame rail, or an AC Delco substitute. Need to be certain the substitute does not require constant voltage.

I have searched for other pics, but have not found others.

@pngunme ?

 

[Downey]

(1) I just picked up a 6 port valve at the Pomona swap meet this morning, any interest before it hits my ebay store- - -lemme know.
(2) The reason for mounting the switching valve 1/2 way between both tanks is because many folks use an electric fuel pump, and elec. pumps are pushers, not suckers, so they should be mounted as close to the tanks as possible. Since the switching valve must be positioned before the fuel pump, the switching valve must be half way between both tanks so that your fuel line can go directly from elec. valve into fuel pump (keeping both close to tanks).

 

[ErikinSC]

Jim, as a matter of fact.... I will PM you in a moment.

I am keeping the stock mech pump, and prefer to not run extra fuel lines to the engine compartment from the rear. Therefore, I figured it best mount the valve between tanks, above skid plate / in area accessible if need to bypass. That will keep the new fuel lines shorter, continue to use hard lines AFTER the valve, and only have to run wires to the DPDT 'Main/Aux' switch....

Do others concur?

 

[Solace in Solitude]

Jim, as a matter of fact.... I will PM you in a moment.

I am keeping the stock mech pump, and prefer to not run extra fuel lines to the engine compartment from the rear. Therefore, I figured it best mount the valve between tanks, above skid plate / in area accessible if need to bypass. That will keep the new fuel lines shorter, continue to use hard lines AFTER the valve, and only have to run wires to the DPDT 'Main/Aux' switch....

Do others concur?

I think I must have copied @bsevans ... Mine is in almost the same place as his. I think this is the best place for the switch valve. It's easy to access. I have a fuel filter inside the frame rail, by the rear passenger wheel, for the aux tank.

The main tank fuel filter is near the Pollak.

Soft lines to/from the saux tank to/from the pollack.

Main tank to/from Pollak still plumbed with the same OEM hard and soft lines that ran to/from the mech fuel pump.

Soft line Pollak to pump and pump to Pollak

Hard line pump to/from carb.

DPDT on dash by headlight switch.

Aux tank plumbed to fuel separator, just like main tank.

OEM senders on both tanks - share OEM gauge, wired thru DPDT and Pollak.

I think that sums it up...

 

[Dennis 1970 40]

I just put a mechanical switching valve centered under front bench seat with a toggle switch to select the tank sending unit. Simple and easy to install.

 

[ErikinSC]

Looking at installing the switching valve under the truck, between the six tank and the OEM tank :

This puts it above the drive line....

Other than accessibility issues, any see a problem?

 

[Dennis 1970 40]

I went with a simple mechanical fuel valve inside cabin between driver and middle seat with toggle for sending unit. It has worked and lasted 45 years.

 

[Solace in Solitude]

You can put it anywhere you want too, as long as it's protected (valve, lines and wiring) from getting hung up and ripped off... But, it's best to set it up like a sewer line... High end at tanks' feed... Low end at mech fuel pump.

If you are running a single fuel pump and it's the OEM mech fuel pump, it 'pulls', via the valve, from whichever tank is active...

If you are running a different or multiple fuel pumps, I would need to know how it's configured.

That location looks accessible...

 

[ErikinSC]

You can put it anywhere you want too, as long as it's protected (valve, lines and wiring) from getting hung up and ripped off... But, it's best to set it up like a sewer line... High end at tanks' feed... Low end at mech fuel pump.

If you are running a single fuel pump and it's the OEM mech fuel pump, it 'pulls', via the valve, from whichever tank is active...

If you are running a different or multiple fuel pumps, I would need to know how it's configured.

That location looks accessible...

I am running an OEM mech pump - and thought the same thing as you Danny. I just wanted the Switch closer to the tanks -and not add a flexible fuel hose inside of the skid plates.... Keep switch up at about the same level as top of aux tank, and bottom of stock tank, effectively same length of fuel lines from Aux - switch as Stock - switch... and then route from Switch to hard fuel lines. Obviously, I will install fuel filters on the I/P side of the Switch.... and leave the stock on at the fuel pump location.

Just making sure someone else has not had a problem - that I have not read about yet - with the mounting location above.

 

[ErikinSC]

I went with a simple mechanical fuel valve inside cabin between driver and middle seat with toggle for sending unit. It has worked and lasted 45 years.

Dennis - I had already planned to buy the electric switching valve and wire for dual OEM senders. I recognize the simplicity of the motorcycle style "On - Off - Reserve" style 3 position switch..... and it could easily work as an 1/8 mile limit anti-theft device as well.

 

[427060]

There's also the option to feed the main tank from the aux using a small electric pump. This requires a bit of wiring, but eliminates the possibility of valve failure or leaks close to the engine. I suppose it's a matter of which failure modes seem less troublesome.

My vehicle runs +40 psi to the fuel rails so keeping the lines intact is more critical for me.

 

[Solace in Solitude]

I think you'll be fine in that location Erik... My aux rank draws (feeds) from the top.

My Pollak is almost level with the mech pump... Maybe slightly lower... I have no problems.

You only need 3-5psi at an Aisin carb... I can't recall whether you are still running the Weber... Or what the Weber requires.

 

[ErikinSC]

Yes, Danny. Still have the weber with a THC carb on back order.

Got the mounting plate opened up today for the OEM sender - I'm liking the progress.

Next will be to drill and tap the sender mounting holes. Right now it's time to head to Columbia, SC to take my son to watch the Gamecocks and Crimson Tide men's BB game.

 

[GUGISMAN]

Manual valve, mounted in the little hump, on the floor. The stock mechanical fuel pump has no problem delivering fuel from the rear mounted aux. fuel tank. I do have to pull over, or be stopped somewhere safe, in order to reach under the console to switch the valve. I also use the valve in 'off' position as another measure in case of theft...

 

[ErikinSC]

Finished the work to install the stock OEM sender into the Marks Off Road plate.

Carefully marked and drilled the first two holes, should have been only one, then marked and drilled the others. I didn't want an alignment issue and the soft aluminum could strip. After marking, drilled with 11/64" bit, tapped with a 5.0 mm x 0.80 tap.

The finished product, mocked for install. I will stamp an S-supply and R-return on the top plate, and probably mark the back edge of the fuel cell also - since you can't see the top once installed. Might even color code everything with matching colered zip ties....

Used a bit of steel wool to soften all of the edges and polish the aluminum up a bit.

Had one screw closer then intended - so I routed a small section to clear more easily.

Ready to finish plumbing and install tank this week. Truck has been sitting on the lift at the shop for a month now.

 

[Weber Sarge]

I spy a Black and Decker Workmate - still have mine after nearly 40yrs ...lol . They are quite handy - need to make new tops for mine but I'm trying to find some 5x1 aluminum plate to get away from the wood so it can be a bit sturdier for metal work . Good job on the sender unit , btw ...
Sarge

 

[ErikinSC]

Disassembled, test fit fuel pick up sock and installed sender plate into aux tank tonight.

Used red hi-temp grease to make more secure seal around the cork gasket - but just made the whole job messier than necessary probably.

Getting the inside plate lined up was easiest the first time - out of the tank LOL - and not too bad the first install time. The return fitting kept wiggling loose, so I removed the plate, reassembled the 90* fittings with some Blue Lock-Tite, and then finally dropped the inside ring during the second install.

I'll add the wiring (and ground connection- should have used the later model sender with a ground, oh well) tomorrow, and run the fill hose, vent, return and supply fuel lines to the 6way switch.