Is there any advantage in fitting a larger Dia fuel pipe? I'm thinking of replacing the fuel line while I'm cleaning everything out in my new purchase before attempting to fire it up and I noticed the existing fuel line is larger except at the tips where the pipe is reduced to match the fittings.
Do you get a better performance when running low on fuel or going uphill?
Anybody else tried this?
Nope, unless you're running a small block Chevy.<g> JMHO. dave
For a normal T and normal T driving a stock fuel line is great.
Note, you commented, "I noticed the existing fuel line is larger except at the tips where the pipe is reduced to match the fittings." Unless that is a Canadian or for your 1926s a New Zealand Factory item, the stock fuel line for the USA Model Ts was one diameter the entire way. The fittings on the ends of the line were originally felt see Lang's https://www.modeltford.com/item/2913.aspx . Some folks substitute a piece of fuel line the correct size to replace the felt. And the vendors also offer a neoprene version see: https://www.modeltford.com/item/2913N.aspx).
But your description indicates that the line may not be original (not a problem). But if it is made from copper -- that may be a problem as it tends to work harden and break. Especially if you are using the brass compression ferrule with a copper line it will tend to fail first at the ferrule area. Ref: http://www.mtfca.com/discus/messages/80257/116133.html
Hap l9l5 cut off
Hap the existing line is copper, larger Dia and moldered to the original sizes at the ends, its obviously home made but i'm interested to know if there is a reason for this approach?
The reason for that probably was better fuel flow, or rather the "BELIEF" in better fuel flow. Under certain conditions, like low fuel in tank, going up hill, slightly tight bend in the line etc, a larger line MAY help a little bit, and that little bit MAY be enough to make some positive difference.
ON THE OTHER HAND, it has been proven that under other certain conditions, the larger line is more prone to vapor-lock and can actually cause trouble.
Under most conditions, once a minimally large enough fuel line size is reached? Going larger, a little, or a lot, will make almost no difference (unless you mount that huge pipe a few inches above the carburetor level and the volume contained within it could actually allow the engine to run a whole another mile before the engine quits after the tank is empty). (I am being strangely funny there!)
All in all, it doesn't matter a lot. If you feel more comfortable with the larger line? Leave it, and don't worry about what a purist thinks. If you want to be a purist? make it right, and don't worry what others think. If you are concerned about reliability (and you should be)? Splices can and occasionally do break. Also, steel fuel lines are generally better than copper lines. The copper can and occasionally do compress, harden, or break. Steel lines fail less often if properly installed. Brass tubing fuel lines are about halfway between copper and steel for reliability, but hard to find these days.
Drive carefully, and enjoy, W2
I run a 3/8 fuel line stepped down to 5/16 at the ends. It does make a difference. I burn my tank dry. With the factory 1/4 line I would loose power with about three gallons in the tank. Also have no problem vapor locking.
Thanks Wayne, I may just leave it as is and monitor.
Dean that's interesting, The previous owner had several T's and this was the one he drove the most and I have a feeling this was done for a reason but he's longer here to ask.
What does the radiator have to do with the fuel line?
This came up on an earlier post from a T owner whose T seemed to lose power when going into high gear. It ran fine standing still but when starting to drive the car in the usual way it just started losing power.
An answer from another poster was to keep the tank near full. I do have to say that when my T's tank gets pretty low I have noticed it doesn't seem to start as easily.
A stock T doesn't have a fuel pump and to me it only makes sense that a little larger gas line would help the flow of gas.
To get rid of the restriction caused by 1/4" pieces of line at the ends of the larger line, you can drill out the pack nuts and the "sockets" in the fittings where the fuel line goes and use 5/16" steel brake line.
The carburetor needle / seat orifice is the same size - about .125" - no matter what size fuel line and fittings that you install. This is smaller than the inside diameter of 1/4" fuel line.
I tried this about ten years ago based on comments from others on this forum, removing the sweet potato and installing a high flow 1/2" NPT ball valve, a 1/2" NPT fuel strainer from a diesel tractor, and then 5/16" fuel line from the tank to the carburetor. There was no difference in performance.
Two gallons is plenty; one gallon isn't enough. I experienced this yesterday. There was a gallon in the tank when I headed for town. About a mile from home the car pooped out and I had to use the spare gallon of fuel I was carrying in the trunk. The higher tank in the improved cars may be better in this regard, but for 1925 and before, with the lower tank, consider one gallon the same thing as empty.
Royce's experience with the wider fuel line doesn't surprise me. If the width of a doorway allows only one person at a time to pass through it, a wide hallway leading to that door won't change it. In the fuel system, the float valve is the door.
I consider 3 gallons as empty, particularly in the case of any sort of non - level driving surface. If I am within a mile of a gas station and the level is below 3 gallons I am getting gas.
" I do have to say that when my T's tank gets pretty low I have noticed it doesn't seem to start as easily. "
You're not starting the car using the gas in the line or in the tank. You're using the gas already in the carburetor bowl. As long as there's gas in the bowl, the tank could just as well be empty and the car would start the same. (Just won't run long)
As long as you don't want to use that last 3 gallons in the tank, you might as well give it to me.
I am often amused by some of the gas line discussions. Like things electrical everyone seems to feel that MORE is BETTER. Royce's experience is real of course but the number of people who swear otherwise is puzzling. I look at it this way. If your T got 4 miles to the gallon then it would use 1 quart of gas in a mile. How big would the diameter of a uniform stream of gas be if it contained 1 quart of gasoline and was a mile long. It would contain 67.375 cubic inches of gasoline and since a mile is 63360 Inches then that would be .0010633 cubic inches per inch which would come out to be about .0368 Diameter and that would mean the 3/16 inside diameter (.188") of the T gas line would have about 26 times the cross sectional area needed to carry that stream of gas. Just a comical picture way of looking at the issue. Of course most T's don't use anywhere near that much gas in a mile anyway but I chose 4 MPG to make the math easier with 1 quart per mile. I have not double checked my math and my calculator doesn't have a pi key so I used 3.14 when figuring the area of the circles. As others have pointed out the limiting factor isn't the gas line anyway - its the needle and seat valve orifice that appears to be the smallest item but the discussion is about gas lines.
I run 1/4 brake line have tried 3/8 and 5/16 only diff I noticed is when the tank is low but this was the only think I found if you have room add some spacer under the tank to raise it a much as you can solves this