Minimum gas in tank to be on safe side?

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rainer
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Minimum gas in tank to be on safe side?

Post by rainer » Sun Jun 05, 2022 4:37 am

Hello.
I am wondering about minimum amount of gas I should have in my tank (T Touring '16) to get no troubles when driving uphill.

I do have a gas gauge.and I currently measured 20 liters (=6 gal) in the tank. How deep can I go to be still on safe side? Nothing is more worse than driving uphills a frequently used street and the engine stops.

If you could tell me your experiences?

Thank you.
Model T Touring 1916 (brass & black), 95% original
I am from: AUSTRIA, EUROPE

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Rata Road
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Re: Minimum gas in tank to be on safe side?

Post by Rata Road » Sun Jun 05, 2022 5:24 am

Would depend on how steep the hill is and also how long the climb is. Lifting the tank up a couple inches helps.


Dan Hatch
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Re: Minimum gas in tank to be on safe side?

Post by Dan Hatch » Sun Jun 05, 2022 6:12 am

Get one of Scott’s new fuel valves and you can go a lot lower.


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Re: Minimum gas in tank to be on safe side?

Post by Norman Kling » Sun Jun 05, 2022 10:56 am

I like at least half a tank in the cars with tank under front seat. Don't know how much is needed with tank under rear. The 26-27 can go almost empty up hills.
Norm

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Re: Minimum gas in tank to be on safe side?

Post by KWTownsend » Sun Jun 05, 2022 11:19 am

In my 40+ years of Model T driving, I only had to back up a hill one time in my 1919. The gas tank was almost empty. With six gallons you are good to go. If I will be out all day, I generally fill the tank to within 1" of the top (otherwise it'll slosh and my wife will comment about the gas smell) and know that I can drive all day long.

YMMV

What size of fuel line are you using? I like to have a shut-off valve right before the carburetor. I have found that with the original 1/4" line a valve with restrict the fuel flow and negatively effect the performance. I like to use a 5/16" fuel line and the hard-to-find 5/16" shut-off valve.

: ^ )

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Re: Minimum gas in tank to be on safe side?

Post by Art M » Sun Jun 05, 2022 11:29 am

Half full on an 8 percent grade, which is as steep as the roads get in my area.

Art Mirtes

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Re: Minimum gas in tank to be on safe side?

Post by TRDxB2 » Sun Jun 05, 2022 12:51 pm

"It cost as much to keep a gas tank half full as half empty" until you run out of gas :lol:
To calculate the approximate angle use this calculation tan (X) = opposite side/ adjacent side and then convert that value to degrees
The angle X is the slope of the hill and that depends on the height of the fuel (opposite side) in the tank because that can vary and the distance from the carb to the sediment bulb (adjacent side) is fixed
Foe example
the RED line represents when the carburetor is higher than the fuel in the tank
the GREEN line is the distance from the carburetor to the sediment bulb
calc.jpg
So these numbers are just to show the example
The fuel height = 6 inches and the distance between the carb & sediment bulb = 48 inches
So 6/48 = .125 which is the Tangent of the angle x.
To convert that is easiest to use the internet calculator https://www.rapidtables.com/calc/math/A ... lator.html
arct.png
arct.png (43.85 KiB) Viewed 2965 times
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slope.png
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Re: Minimum gas in tank to be on safe side?

Post by TrentB » Sun Jun 05, 2022 1:16 pm

Only unplanetary people back up hills.

I keep a special gas cap with me when I am doing really steep climbing (e.g. going over Stony Pass out of Silverton, CO). This cap has been fitted with an old metal inner tube stem. When the motor starts to starve for fuel, I stop, change gas caps, and use the tire pump to pressurize the gas tank. It takes about two lbs of pressure to do the trick. This is sufficient air pressure to force the gas up to the carburetor, and keeping the car running up over the hill. Do not put more than about 2 lbs of air pressure in the tank. Any more than that will force fuel past the carburetor needle and seat flooding the carburetor and engine. Once over the hill (or mountain in my case), I switch back to the regular gas cap and continue on my way.

Just one more thing…. One of the basic safety rules of Model T driving is you always go down the hill in the same gear you went up it.

Respectfully Submitted,

Trent Boggess


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Re: Minimum gas in tank to be on safe side?

Post by Scott_Conger » Sun Jun 05, 2022 1:41 pm

either a 5/16 fuel line, or a firehose, will both supply the same fuel through the float valve at any given pressure, which is the greatest single restriction in the fuel system, and the vast majority of commercial valves have only around 60% of the flow area that originally came on the carb...pressurizing the tank like Trent does, is of course, helpful, but in any other situation, (picture included for illustration only), good luck climbing hills with a partial tank, with the valve on the left...
standard vs full flow.jpg
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Re: Minimum gas in tank to be on safe side?

Post by Steve Jelf » Sun Jun 05, 2022 4:46 pm

"Two gallons is plenty. One is not enough." :)
The inevitable often happens.
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Re: Minimum gas in tank to be on safe side?

Post by Rata Road » Sun Jun 05, 2022 4:49 pm

And of course keeping it full is a good investment the way the price goes up every week.


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Re: Minimum gas in tank to be on safe side?

Post by Alan Long » Sun Jun 05, 2022 10:26 pm

My standard message to all T Owners who have the tank under the front seat is “if it’s not above half full it’s empty”
Alan in Western Australia

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Re: Minimum gas in tank to be on safe side?

Post by Steve Jelf » Sun Jun 05, 2022 10:53 pm

IMG_1197.JPG
You don't have to worry about it if you never leave home without these. They have saved me an unscheduled long walk more than once.
The inevitable often happens.
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Topic author
rainer
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Re: Minimum gas in tank to be on safe side?

Post by rainer » Mon Jun 06, 2022 3:33 am

Hello, TrentB
TrentB wrote:
Sun Jun 05, 2022 1:16 pm
Only unplanetary people back up hills.

I keep a special gas cap with me when I am doing really steep climbing (e.g. going over Stony Pass out of Silverton, CO). This cap has been fitted with an old metal inner tube stem. When the motor starts to starve for fuel, I stop, change gas caps, and use the tire pump to pressurize the gas tank. It takes about two lbs of pressure to do the trick. This is sufficient air pressure to force the gas up to the carburetor, and keeping the car running up over the hill. Do not put more than about 2 lbs of air pressure in the tank. Any more than that will force fuel past the carburetor needle and seat flooding the carburetor and engine. Once over the hill (or mountain in my case), I switch back to the regular gas cap and continue on my way.

Just one more thing…. One of the basic safety rules of Model T driving is you always go down the hill in the same gear you went up it.

Respectfully Submitted,

Trent Boggess
This I was also told to me by 'Leonhard Lanzl' from Gemany, doing the technical part at www.alpenchapter.com for Germany and Austria. He uses an bellow for filling up inflatable mattresses and an open tube (without valve inside), but principle is the same. :D

I also think about buying a little 6V air pump as used for living fish transport (like this one https://www.pollin.at/p/daypower-luftpu ... wwQAvD_BwE). I can easily connect it below the seat to battery (because there I have an emergency battery switch and therefore 6V. If I don't find a smaller one. Needs less room and also I don't have a tire pump. All I need to do is drill the breathing hole in the tank cap a little wider and glue or solder in a short piece of ø4 mm brass pipe, reaching out 1/2" or less (just long enough) to allow a thin plastic tube to be attached. This pump has valves, so it will keep pressure in the tank when turned off again.

I also saw a fuel pump for veteran cars, but this would require a permanent installation, I don't like that.

Rainer
Model T Touring 1916 (brass & black), 95% original
I am from: AUSTRIA, EUROPE


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Re: Minimum gas in tank to be on safe side?

Post by troutjohn » Mon Jun 06, 2022 5:56 pm

In southeast PA on a tour last summer I ran low of gas on the last hill of the tour. There were 4 gallons of gas in my 1913 (tank under the seat). I recommend a minimum of 5 gallons. I still get kidding from other club members for running low on gas.

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