Fuel System: Possible Vapor Lock Solution?

[creegster]

Hi everyone-

I came across this video about how to prevent vapor lock with modern gas. Does anyone know if this works?

https://www.youtube.com/watch?v=-t6geNGbEXM

Im interested in trying it, but Im not sure how to get the return line back into the gas tank. Would I just add a "T" to the line running out of the tank, right before the tank?

[Bullet]

There is quite a bit of information on this here on the forum. The fuel filter with one in and two about is what is us3d by quite a few people here on the forum. Most use this with an electric fuel pump. I am not certain if that is required but helps. Most people recommend plumbing the return gas line into the gas filler neck, not a T into the tank out line.

I have a 64 Cruiser and have had vapor lock on my car for 10 plus years and finally this year added an electric pump, removed the manual pump and added a return line. I did not use a gas filter as in the video, but added an R1 type filter near the carb. Since doing these changes I have not had a lick of problem. I drive my car as a daily driver.

Mark

[creegster]

Ah- The gas filler neck makes a lot more sense. Thanks!
I read through the other posts, and it seems that the return line needs to be brazed into the filler neck of the tank.

Anyone have a recommendation on the fuel filter with the return line running off it?

[altair]

I have a different point of view about vapor lock, firstly I don't believe the fuel will ever boil in the fuel pump, if there is fuel at the pump supplied from the tank it will pump it through the the carb it will not cavitate. I have tested a fuel pump with a 10 foot hose standing on a ladder with the hose in solvent and with the pump full of air it took about 5-6 strokes for the solvent to reach the pump. I think vapor lock is the most misunderstood issue and many people have a different interpretation as to the cause and cure. My opinion is that the fuel will boil in the carburetor spill over and flood.
Many of our older engines have compromised cooling systems and faulty heat risers. With an open cooling system every time the engine cools down it sucks air to the system the oxygen in the air reacts with the cast iron surfaces and causes rust and corrosion. Many of these engines when opened up are full of crud, this is eliminated with a closed system. My 259 was cleaned inside all the plugs were removed and it was full, each plug when removed was solid debris. My heat riser was serviced and operates properly the thermostat is 160*and it runs right on 160* and rarely creeps over that even idling in 100* temps. My carb has never boiled over. This is a 259 V8 in a 54 Champion using the 6 cylinder radiator and fan. I think designing a closed cooling system would pay great dividends. The crud build up is inherent in the design and requires maintenance from time to time if not tended to on a regular basis over heating will occur and gasoline will boil in the carb and this what is referred to as VAPOR LOCK when it really is gasoline boiling in the carb and flooding the engine. You wait 10 - 15 minutes the gasoline evaporates and it starts up again. As humans we believe what we want to believe and hear what we want to hear and sometimes it couldn't be farther from the truth.
I was listening to a chap the other day discussing problems with his AC and he was convinced that because his cooling system was low on antifreeze was the problem, he put in a quart of antifreeze and the AC instantly started to blow cool air, I had to bite my tongue.

[doofus]

be careful working around the filler neck. it is coated with lead all over. a mopar filter from late 70's has a return line. Luck Doofus

[jts359]

I put the return line in my filler neck on a 64 Daytona and tapped a 1/8 npt fitting into it with no problem , I used a R-1 filter also and I was surprised how much fuel was returned with the mechanical pump , Ed

[Flashback]

Without a lot of Talk. YES, it works ! It has worked for me on nearly every instance I have used it over the years.

[JoeHall]

I have a different point of view about vapor lock, firstly I don't believe the fuel will ever boil in the fuel pump, if there is fuel at the pump supplied from the tank it will pump it through the the carb it will not cavitate. I have tested a fuel pump with a 10 foot hose standing on a ladder with the hose in solvent and with the pump full of air it took about 5-6 strokes for the solvent to reach the pump. I think vapor lock is the most misunderstood issue and many people have a different interpretation as to the cause and cure. My opinion is that the fuel will boil in the carburetor spill over and flood.
Many of our older engines have compromised cooling systems and faulty heat risers. With an open cooling system every time the engine cools down it sucks air to the system the oxygen in the air reacts with the cast iron surfaces and causes rust and corrosion. Many of these engines when opened up are full of crud, this is eliminated with a closed system. My 259 was cleaned inside all the plugs were removed and it was full, each plug when removed was solid debris. My heat riser was serviced and operates properly the thermostat is 160*and it runs right on 160* and rarely creeps over that even idling in 100* temps. My carb has never boiled over. This is a 259 V8 in a 54 Champion using the 6 cylinder radiator and fan. I think designing a closed cooling system would pay great dividends. The crud build up is inherent in the design and requires maintenance from time to time if not tended to on a regular basis over heating will occur and gasoline will boil in the carb and this what is referred to as VAPOR LOCK when it really is gasoline boiling in the carb and flooding the engine. You wait 10 - 15 minutes the gasoline evaporates and it starts up again. As humans we believe what we want to believe and hear what we want to hear and sometimes it couldn't be farther from the truth.
I was listening to a chap the other day discussing problems with his AC and he was convinced that because his cooling system was low on antifreeze was the problem, he put in a quart of antifreeze and the AC instantly started to blow cool air, I had to bite my tongue.

The only way you can get by with a V8 motor and six cylinder radiator is because you live in Canada. Most of the other experiences you relate are also because you live in Canada. Every Studebaker motor should have the crud cleaned from the block. However, once cleaned out and using modern coolants, it will remain clean between rebuilds at 100,000 miles or 15-20 year intervals. Fuel will vaporize anywhere temps get hot enough: lines, engine mounted fuel pump, fuel filter and carb. I believe you, that you have only ever experienced fuel vaporizing in the carb but, again, you live in Canada.

[pinehurstbob]

Use the Chrysler filter, return line to filler neck in the tank, with electric fuel pump. Have been running this in both my Lark 259s for past 8 years and not once have I vapor locked since converting to this set up. Only fuel problem I have had is pump failure and that is directly related to the quality of off shore parts. So now I carry a spare fuel pump that you can change on the road, just like you would a tire.
Bob

[JoeHall]

A good snapshot of how prevalent the Studebaker vapor lock problem is, occurred a few years ago at a South Bend parade, on a hot summer day. At least half of the Studes had problems.

I have ran return lines in Studes since around 2005 and, like many other remedies, they help, but do not eliminate vapor lock. My opinion, someone should develop a multi component, anti-vapor-lock kit for us: a piece of coat hanger to wire open the heat riser valve; phenolic carb spacer; manual choke adapter; fuel return line kit; HD radiator with minimum of 3-rows; HD motor fan, and 16" pusher fan for front of radiator with manual switch inside the car.
Don't bother with a 160 thermostat, if weather is cool enough for the motor to stay 160 or below it ain't gonna vapor lock anyway. A 180 is more realistic, since the motor is gonna see 180-210 temps during hot summer weather.

Even with the above kit installed, you will only reduce vapor lock by maybe fifty percent. Still, that is significant if used to living with it at its worst, and makes it almost seem, "cured". If you really wanna get rid of vapor lock, install EFI.

[creegster]

Thanks everyone for the advice!
EFI, while a great idea, is outside my skillset and budget. (I have a Chevy engine, so its possible to upgrade) :-)

I'll look into adding an 1/8 NPT line to the filler neck, with an threaded nut brazed in.

[JoeHall]

Thanks everyone for the advice!
EFI, while a great idea, is outside my skillset and budget. (I have a Chevy engine, so its possible to upgrade) :-)

I'll look into adding an 1/8 NPT line to the filler neck, with an threaded nut brazed in.

If you use a 1/8 pipe thread 'L' fitting, with nipple tinted down, it will never move since the hose helps hold it in place. Locate it 3 to 4 inches down, where you can see the stream if the cap is removed. Also, you'll need an inline restrictor to reduce flow, otherwise the pump will not be able to keep up, and the motor will experience fuel starvation. When new, the filters mentioned above will hold hold back-pressure and restrict return line flow, but that quickly lose that ability. An inline restrictor will maintain restriction forever. With a .030" hole in the inline restrictor, you will see a stream of return fuel that nearly hits the opposite wall of the filler neck.

[pinehurstbob]

To further clarify my set up, I have eliminated the mechanical pump and positioned the lines as far as possible from the heat of the block. Both my cars have 2 barrel carbs. There is fresh cool fuel flowing constantly to the carb or back to the tank. Is this not one of the features of modern EFI? Works for me.
Bob

[jts359]

I did not have to braze a nut on the filler neck , I just tapped 1/8 npt , works great ,Ed

[Farmers Market Pro]

one reason studebakers have trouble with vapor lock is their long fuel line from fuel pump to the carb my 66 cruiser has never vapor lock my 62 champ has the line on my champ is 10 to 12'' longer . a car setting at a stop light has very little gas moving thru the line so longer the line hotter the gas gets