putting in a stainless fuel line in the T.
Neighbor says there should be a "dip" in the fuel line after the fuel tank lower than the carb to allow the fuel to gain higher pressure. My thought is my neighbor is a "dip"...
My reasoning is that the most direct route between 2 points is a straight line...making turns in a fuel line invites vapor lock.
There are probably more views in this argument...just wondering what you think.
Thanks,
cj
Gravity is still forcing the same pressure with or without the dip I would think.
Collin - I think there is something to the "dip" in the fuel line thing, but I don't think it has anything to do with pressure. I think it has to do with the fact that any air bubble in the fuel line will tend to rise up to the end of the fuel line so you can get rid of it rather than have it remain in the fuel line and cause problems with flow.
(Interesting that the last thread had to do with "Bump" and this one has to do with "dip"! Wonder what's next,....ha,ha,...harold)
So you should make your new line about 200 feet long, with several coils going down a few inches off the ground. That will produce so much pressure it will be like having a fuel pump.
Steve, it's not the length of the line nor the drop from the tank which creates the pressure. What one needs to do is make the dip as DEEP as possible. This means routing the line up from the tank, across one of the top bows and then down to the carby. With your 200 feet of line that would make the chances of running low on a steep hill rather remote. Not a bad idea!
Cheers,
Allan from down under
Steve, it's not the length of the line nor the drop from the tank which creates the pressure. What one needs to do is make the dip as DEEP as possible. This means routing the line up from the tank, across one of the top bows and then down to the carby. With 200 feet of line that would make the chances of running low on a steep hill rather remote.
Cheers,
Allan from down under
Hey Allan,
You have the advantage of having your carburetor much lower than we do in the northern hemisphere, you should be able to drive straight up a cliff with out using fuel pressure.
Best
Gus
I had a problem going over 30MPH on the flat until I shortened the fuel line to get the dip out.
I was running a down draft carb on a '26 touring.
The carb was slightly lower than the bottom of the fuel tank but the fuel line wen down from the cowl tank and then back up to the carb. After shortening the fuel line enough to eliminate the dip I was OK until I came to a hill. I now run a fuel pump.
I am not saying Collin's neighbor is a dip but I think he is wrong.
I think the only thing a dip would do is create a place for moisture to collect. The only thing that will determine the fuel pressure is the difference between the height of the tank and the carb. That is called head pressure, if I recall correctly. Dave
Stainless?
I remember several years ago a discussion on here regarding brass line or copper line. If I recall, the general consensus was that brass was too brittle and prone to cracking. Copper is more forgiving and was the better choice.
There was no mention of stainless steel and I wonder what their arguments would be about using it.
You don't need a dip in the fuel line. There's no benefit to that idea. I wonder if someone is trying to find more urban legends?
I had no idea that Ford built all Model T's with defective fuel lines until now.
stainless steel brake line looks exactly the same as the original fuel line in copper with a nickel coating, same small seam line on one side, your local big rig / truck supply shed should have it, thats where mine came from.
Unless l'm mistaken copper suffers from stress fracturing over time, but l have no idea how long it takes.
Below is a pic of last weekends HCCA 75 th aniversary rally.
You'll notice the sad BURNT out 13 Overland, not a fuel line but a very full tank of gas on a very hot day, it overflowed and hit the exhaust pipe.
cheers David.
Well that picture is depressing. That SUCKS for those folks! I hope everybody was ok. It looks like it might actually be ok (relatively speaking). As opposed to sometimes when you see car fires and it's so completely burned there's just nothing left.
Yes, that's a downright shame.
Well, at least he can get a new Overland. I just saw a Jeep ad on tv, and they now have an Overland model, even with the original script for the name. I wonder if our friend Chuck (the Hammer) Martel had anything to do with that? Where are you, Hammer?
rdr
Steve: based on my neighbors knowledge and theory, I considered the option you suggested...but simply can't afford all that stainless...;)
David: so sorry about your Overland. On the brighter side, now you have the chance to do it again.
Thanks all, I will try to keep the "dips" out of the garage in the future.
cj
It's surprising how many people are smarter than Henry Ford! He ran the line from the sediment bowl along the lower frame rail and up toward the carburetor. It worked very well except for going up a steep hill with a low tank. The carburetor is still lower than the tank, but the line goes up at both ends. One end is up through the sediment bowl into the tank, the other is up into the carburetor. So the air bubbles will rise to the top. The later cars had the line dip just below the level of the carburetor. There again both ends go up.
The problem lays in a line which has a high area between the two ends. The bubbles will rise into that high area and form a "vapor lock" The gas coming out of the tank will compress the air but when the tank is low the pressure is too low to force the air out, and so the carburetor starves for gas.
All bets are off when you use a downdraft or other non stock carburetor. The cars on which the downdraft was stock equipment had fuel pumps. So if you are going to use downdraft, you need a fuel pump.
Norm
Just for the record, all Model T's came from the factory with BRASS fuel lines. All of them. Some were seamed and sweated and those had to be tested at 10 lbs/square inch pressure as I recall but the non-seamed version didn't have to be tested.
David Dare,
You make a good point. I'm glad we, as a group, don't have a chronic problem with gasoline fires, but sometimes I wonder why we've been so blessed.
I'm pretty sure I have a copper gas line (as opposed to brass) and for now, I just think of it as one of the many little hazards associated with operating a century-old car in a modern context. I really should replace that stupid line (but if I'm going to do that much, I might as well take the car to a radiator shop and have them do the line replacement and a flush/clean/seal job on the gas tank, as well). People wonder why I crawl underneath and shut off the fuel at the sediment bowl when I have a perfectly good shut-off valve more conveniently placed within easy reach under the hood. The answer is that I worry the copper gas line might develop a crack and start leaking in my attached garage. So, unless I'm parked outdoors, I use both valves to shut off the gas.
One other thing: Anytime we're refueling our Flivvers, the exhaust pipe will be seriously hot and it's so easy to slip and spill a dribble of gasoline which can flow down around the cylindrical tank and drip off the bottom onto the exhaust pipe. A little flame under a tank with a wet trail of raw gasoline leading up to the open port could be a very bad thing.
And so, for me, gassing up is an exercise in paranoia that includes getting the passengers out of the back seat, shutting the carburetor valve, opening the battery cut-off switch and placing the fire extinguisher on the running board. I hold that Exxon nozzle like it's a loaded gun; first touching it against the metal frame of the car to ground out any static and then holding it firmly against the open port to prevent any friction potential which might otherwise be built up by the flow of gasoline (a technique I was taught in ground school). And I never fill the tank up to the top. Leaving about a gallon's worth of empty expansion space in there just feels like a good idea.
Yeah, people make fun of me for over-doing it. That's okay.
I am with you Bob. As a fire fighter I could write book from incidents where someone wishes they had been more safety minded. It pays to be safe. It does become a bit of a balance. We still want to have fun. Calling the local Fire Department to stand by while fueling really will not change the outcome much. Think, Be Safe, Have Fun. In that order. Another Bob
I was at the HCCA 75th anniversary tour.
One of the passengers in the Overland suffered 3rd degree burns to his legs because he went back to retrieve his wife's purse.
He'll be OK & didn't need skin grafts as of Saturday.
Mark
Dad has a '17 Overland with the fuel tank in the cowl. One mistake and you could end up with a lap full of gasoline - not a good thing.
Replacing the fuel line is one of those things that may not be necessary, but will make me feel better while the T is sitting in the garage with the other cars.
Thanks all,
cj
Do not use brass or copper on a driver they will both work harden and crack after time from the flexing of the frame and fail. It will take a while but eventually it will happen use stainless or just plane steel, you will protect yourself and the next owner. The line doesn't need a dip, it just needs to be as straight and as far away from the exhaust as possible.
Maybe your "dip" is a plumber and he likes a "P" trap under there.
I used steel brake line to make my fuel line and so far so good over the last 4+ years.
Hi, I made a full loop as you see in brake lines. It gives the line flex room. 12 years and no problems. Scott
G'day Colin, lucky to say not my car, l'm a little ways from there, but the point of both fuel filling and condition of the fuel line at both ends can not be over emphasised.
I have in both my 13's a small shut off valve located under the floor mat 6 or 8" from the tank, convenient, safe and above all easy to get to in a hurry if something goes wrong.Its a small 1/4" gate valve, but a 1/4" ball valve works just as well.
David.
Collin I hope your Neighbor doesn't read this Forum.. Yikes!!
Remember the sign at the fuel point for light planes at the airport, "NO MOVEMENT WHEN FILLING", ya either stay in or ya stay out, but not both.
Does anyone know for sure how the fuel lines on the '09-'11s were routed? With the tank outlet outside the frame, the line must cross over the frame, tuck inside it, go behind the motor mount block then on to the carburetor. The fuel line I have now, which may be causing problems, is routed on the high side of the wood block. With its gentle bends I can remove and replace it without removing the wood block. If I were to make a line with a dip to go to the low side of the block, I would have to remove the block to install it.
The only illustrations of fuel line installations I have are the ones in The Service Bulletins, and they only show later tanks with center outlets. On page 239 for touring car they show the fuel line between the wood block and the frame and on page 295 they show the line between the pan arm and the trans cover. Was that a change in later years?
If, on the '09-'11s the fuel line was routed down to the lower frame flange, it wold have taken more material, been harder to make with the sharper bends and harder to install. There would have had to been a good reason for that. If that is the correct original installation to create a dip, that is what I will do.
I recalled a fuel line thread from 2009 that mentioned "Cunifer (Kunifer?)", a copper, nickel, iron alloy tubing that is used as brake tubing especially in Europe that looked like it would be suitable for fuel lines. www.mtfca.com/discus/messages/80257/116133.html. Jim Patrick
Doesn't that picture make for a good reason for a vent tube? I installed one on my T and directed the tube away from the exhaust system. Having worked with missiles and other explosives, 1 gallon of gas heated to the right temp compared to 1 pound of dynamite the gas will put out more of an explosion. Years ago I was building up a 61 Chev 1/2 ton and I needed a few parts. Where my father worked someone had started a fire by accident and it burned most of their pickups and the gas tanks that were full prior to the fire, the truck burned but the gas tank didn't explode so we took the tanks out and poured the gas into containers and ran it through my truck. The only tanks that exploded were those that were low on gas. It's not the gas that blows but rather the fumes.
This would be a good place to remind members and newbies to be careful when working in garages with gas a fueled heater, water heater and/or clothes dryer as the gasoline fumes can flow across the floor many feet from its' source and ignite at the pilot flame having catastrophic results. Jim Patrick
A Model T with a frame mounted gas tank absolutely needs a dip in the fuel line. I proved it. Norm is correct in his explanation of how vapor bubbles can be trapped in a fairly level line. With slow gas movement, the bubbles can't get flushed and just stay there. Norm got me to thinking about fuel supply problems I have had in the past when dealing with long lines for fuel oil furnaces. Difficulty in bleeding hydraulic brake lines on trucks with long frames also came to mind.
I was never sure why all those early motorcycles and tractors had fuel lines that made a 360 degree loop; I thought it was for ease of fitting or maybe to allow for some movement of the connected components. The only reason for the downward loop, which is actually a dip, is to make the fuel line not have any way of possibly trapping bubbles. Farmall tractors from the 50's were still coming from the factory with that 360 degree loop.
The difference in elevation between the sediment bowl outlet and the carburetor inlet is only about 1/4" drop. On a three foot run, unless your pipe is straight as an arrow, you are going to trap vapor bubbles.
Some of you guys who posted above shouldn't make fun of technology you don't understand. None of us are ever so smart we can't learn something.
As far as raising the pressure, putting the correct dip in the fuel line did raise the fuel pressure from not enough to sufficient.
The only dip you need in your gas line is to keep it away from the exhaust pipe.
'09-'11 fuel lines didn't have to contend with the exhaust pipe. Ford put a dip in them for the specific purpose of eliminating vapor bubbles.