How do you fill your tanks?

[steve_D]

Calling all those who have tanks coupled together.
My tanks are linked top and bottom with dash 6 pipes.

Question
When filling from just one side does the second tank fill faster if you open its filler or does it make no difference?

I don't have the answer as I have not filled it enough times yet.

Thanks
Steve

[bigmack]

Hi Steve,
I'm not real sure that it matters. That -6 pipe is really slow. I followed USCANAM's suggestion and changed mine over to two -10 lower fittings b/c of the slow fuel transfer. You can do this, with care, with the tanks still in the car by the way. When my tanks were -6 I just filled the tanks individually. With -10 its a lot quicker to fill both tanks from one side. I think its a worthwhile upgrade at some point for you.
Are you enjoying the car? I remember that you just SVA'd it recently. I just registered mine recently also, and still haven't been able to really settle my nerves when driving it. I'm always worried about something breaking and being stranded. I guess it just takes time to build up confidence in a self-built car. Still working out a few small details also. Like forgetting to connect the aircon evaporator drain and having your sock soaking wet with water. I love the sound of the engine, but I think a radio is a necessity for longer drives. The motor rumble is sort of hypnotic after a while. I like to rest my arm on the side-cill while driving, but the bouncing around can sort of be rough on your elbow. Might need a little padding of some kind. These cars have a ton of performance don't they? Even with aircon running at full blast. Wow!! Keep me updated on your experiences with the car.
Cheers!
-Mack

[andycanam]

open one side, fill to brim and pay.......


but then I did have -12 balance pipe


Clive used to fill up from both sides with the -6 balance pipe.

>> Edited by andycanam on Tuesday 8th June 21:32

[gdr]

Fill individually. Very little flow from side to side with -6 and other filler cap in place so you can get both tanks topped up to brim (I have not fitted vents).

[USCANAM]

Like Mack said, it's possible to carefully drill out the existing -6, and re-tapping the welded in bung for a 1/2" NPT fitting. This will allow you to install -10 hose connectors. -10 will flow almost 4 times as much as -10.
When filling the tank, I can fill them completely from one side. Takes about 5 minutes. The trick is to keep the tank you're filling always full to keep the head up. Also make sure the car is level, as the fuel will start to pour out the overflow on the other side if it's lower.
Ask me how I know!!!
Jack

[ultiman]

Steve
I can assure you that you will have plenty of practice the way they chew up super unleaded.
Nick

[steve_D]

ultiman said:

Steve I can assure you that you will have plenty of practice the way they chew up super unleaded. Nick

We will find out Thursday won't we.

I got 16mpg on the run up to the midlands a couple of weeks ago. I have 2 other cars neither of which do better than 21mpg so the Ultima has not come as quite the shock it may do to other new owners.
Steve

[phil.borden]

Don't forget what the real reason for having the top link connection is for. The primary use is for safety; thus allowing fuel that may be inadvertently pumped into a tank to flow back to the other. This stops fuel being pumped up the filler neck and out the overflow.

I have yet to fill both tanks at the same visit to a petrol station. I guess it takes practice and would have to find pumps with hoses long enough to reach both sides. I have not tried to save embarrassment!

I have a 6.3L chevy 530bhp and seem to be getting about 14mpg (only done 340miles since SVA) and on short journeys, and a reasonable number of fill-ups or course!

[Crazy of Cookham]

Whats the problem?. It is really no great deal to fill both tanks. It also tends to look cool in the fuel station. I have never yet found a pump taht would not reach. The problem is how often you fill an Ultima not how you fill it. Thats all part of the fun.

[canam-phil]

phil.borden said:

Don't forget what the real reason for having the top link connection is for. The primary use is for safety; thus allowing fuel that may be inadvertently pumped into a tank to flow back to the other. This stops fuel being pumped up the filler neck and out the overflow.

Under what conditions does fuel get inadvertently get pumped back into one tank?

[davefiddes]

canam-phil said:

Under what conditions does fuel get inadvertently get pumped back into one tank?

If the non-return valve were to stick open for some reason (grit in the fuel, etc).

[canam-phil]

davefiddes said:

canam-phil said: Under what conditions does fuel get inadvertently get pumped back into one tank? If the non-return valve were to stick open for some reason (grit in the fuel, etc).

The reason I ask is surely the pumped flow into the tank would exceed the gravity flow in the -6 cross connection pipe and the fuel would back up into the fuel filler pipe and attempt to get out via the very small overflow pipe in the filler funnel. Or, is the small diameter fuel filler funnel overflow pipe not fitted? There has got to be an air inlet to the tank so the excess fuel would have to exit there.

Another question: Does the unpowered fuel pump act as, or have a non-return function as well as the initial separate non-return valve?

[andycanam]

davefiddes said:

canam-phil said: Under what conditions does fuel get inadvertently get pumped back into one tank? If the non-return valve were to stick open for some reason (grit in the fuel, etc).

In which case if the other tank is already empty then wouldn't you have a major problem very quickly? as my pump could empty BOTH tanks simutaniously within minutes from full with no pressure resistance.
You'd also lose fuel pressure at the carb which surelly would not be good if your using it hard.