Vacuum tank/electric pump

[McCargar]

I Think I’ve solved a problem that has bugged me for a while now. How to have a vacuum tank fuel system with the reliability of an electric pump but still maintain gravity flow to the carburetor?

So if anyone is interested here is what I came up with.

I started by taking the vacuum tank float system apart and removing the vacuum shaft and the breather vent shaft.

I then drilled a hole in the top where the vacuum shaft was to the correct size, which will be threaded for the seat of the needle and seat.  (I just used the needle and seat out of an old Carter carb.) Two things to be aware of; don’t drill the hole for threading too deep as to effect the threads of the vacuum port and the seat should not be too long or the existing float shut off system won’t work properly.

Next on the arm that held the vacuum shaft I threaded the hole where the vacuum shaft was to accept a 3/16(#12) X 24 bass adjustment screw.

Use a #6 X 32 X 1.5” brass screw for a stop adjustment which replaces the breather vent shaft as a stop. The nut on the #6X1.5” screw had to be rounded for clearance. This screw is not secured tightly but left loosey goosey (A technical term) to allow for the movement of the arm.

Put it all back together, make the necessary adjustments, lock tight the threads and move the fuel inlet to the vacuum port.

What you end up with is a great big external carb float bowl that gravity feeds the carb.

 

[Bob Engle]

My 17 Buick came with an electric pump.  They ran a return line to the tank from the vent port to the gas tank.  the pump never builds pressure in the vacuum tank as any excees flows back to the tank.

 

I still plan to return to the original vaccum  tank concept whenever I can colect enough pieces.  They gutted the internals of the tank.

 

Bob Engle

[hidden_hunter]

The one in our 26 was a bit fiddly, but works fine now it has all been cleaned out. When they're working properly you should be able to start from an empty tank it will be able to draw fuel from the rear tank and start within about 15 seconds

[27donb]

The first time I ran out of gas half way up a long hill was the last time I ran on the vacuum tank. 

 

Low pressure low volume electric pump is the cure, with the disconnected vacuum tank left in place for original look. 

 

 

[Brian_Heil]

I need to find the picture of Billy Melton's 1919 Model 45 Buick at the summit of Pikes Peak.  Stock Stewart Warner vacuum tank and system.  19 mile long, 8000ft climb.

[27donb]

8 minutes ago, Brian_Heil said:

I need to find the picture of Billy Melton's 1919 Model 45 Buick at the summit of Pikes Peak.  Stock Stewart Warner vacuum tank and system.  19 mile long, 8000ft climb.

 

And I always forget... Carter BB-1.

 

Maybe a stock Marvel would work better with the vacuum tank. 

 

Still, I wouldn't trade my upgrades, and only Eagle Eyed Experts detect the difference. 

[Terry Wiegand]

And keep this thought in mind - there are those out there who can pick fly s%$t out of pepper.  I personally do not want to take the chance of being outed as a non purist.

 

Terry Wiegand

South Hutchinson, Kansas

[Mark Shaw]

When the vacuum tank on my 24 Buick Master causes it to start surging as the tank refills, it automatically keeps me from driving too fast....

[Brian_Heil]

And something as simple as a plugged or not well vented fuel tank cap can cause a vacuum pump system not to work well.  You need a hole in the cap at least the diameter of some baling wire and a piece of baling wire to keep it clean.  Every time I fill-up, I hold that cap up to the light and check it.

Edited March 1, 2018 by Brian_Heil (see edit history)

[dibarlaw]

When I rebuilt my vacuum tank I threw the crappy regulator away but kept the electric pump in line under the front seat frame rail. It has helped me to do a quick fill on the tank in a pinch. Hopefully when I get the engine back in the car and do some miles up hill I will be able to evaluate better the performance..

[carmover]

I converted mine to electric a couple of years ago and I have been real happy with it.I kept the canister plumbed up to look original. The old carb Doc rebuilt the carb and upgraded the needle and seat to a rochester which can stand up to 3 pounds of pressure.I used a delco pump and a holley drag racing regulator.The car so far is real happy with this set up and I am too.

[Mark Shaw]

On ‎3‎/‎1‎/‎2018 at 5:52 PM, carmover said:

The old carb Doc rebuilt the carb and upgraded the needle and seat to a rochester

So, you flipped the manifold and use a downdraft carb?

[carmover]

Mark,I am using the same Marval Carb that came on the car.The only thing was done was when I called the Old Carb Doctor he asked me if I was going to use the cannister or an electric pump and I told him you couldn't us an electric pump on these marvals as they could not stand but a half a pound of pressure and he said he could set it up to handle up to 3 pounds of pressure so what he wound up doing was he used a Rochester needle and seat and it now handles the electric pump pressure without any problems and you don't have to worry about turning off the fuel or any flooding issues and the car never runs out of fuel even on long hills.I plugged the vacuum lines and left everything hooked up and it looks perfectly original.The cannister has not been modified and could be easily set back up by splicing the fuel line under the floor.I made the fuel line to the carb go slightly under the floor and killed it and weathered the new line so it matches the original line and everything is hidden under the floor I hooked the pump to the switch so it comes on and turns off with the switch.

Edited March 18, 2018 by carmover (see edit history)