I have a 1965 b-body that I would like to add a fuel return line to fight vapor lock. If the line by its self doesn't work I plan on adding a electric fuel pump. Up by the carburetor I will be using the three nipple fuel filter. My question is where has everyone taped in to get the fuel back in to the tank? I have a new fuel sending unit that I could silver solder a 1/4" return line into. Or should I poke a hole in the top for my filler neck. What and how have some of you done this to your car.
Pictures would be nice.

Thanks for the input

Not the exact answer your looking but a question. Are you running an open air filter under the hood?

I had very bad vapor lock on my 65 B-Cuda. Added a second 1/4 inch line back to the tank and drilled a hole in the sending unit then silver soldered a tube with a bent up vent. Still vapor locked but was better. I then added a pusher electric fuel pump, agian helped but on a hot day, vapor locked. I then borrowed my closed air cleaner from my LRT, ran two drier vent hoses down under the front bumper and mounted two scoops made from house floor heat registers. This mod alone dropped my engine temps down about 25 degrees and no vapor lock even with the electric fuel pump shut off.

I have done this mod to a few 413/440 motorhomes too. One or two up to the the modified aircleaner and one to blow cool air on the Thermalquad.

My vapor lock mods are,3 nipple fuel filter,1/4 inch line back to the filler neck and a plastic carb spacer. Mike

The return line will help. Some sending units already have a return line nipple. I like to reroute and insulate the fuel line, keeping it away from any engine heat sources.

If you have room, you can also put a 1/2 inch or better yet, a 1 inch phenolic spacer between the carb and the intake.

Depending on where you live, you may also want to block the heat crossover on the intake.

cant just fix the cause of the vapor lock rather than covering up the problem. just saying its probly something simple like a fuel line laying on a hot intake manifold. or the wrong base gasket.
gust my opinion.

If you go with the 1/4 inch return through the sender unit you'll want to "swedge" the hole open not just drill it...Use a smaller diameter drill bit then lay the sender on a deep well socket...Use a tapered punch to drive through the hole and into the socket opening creating a ledge to the inside so your 1/4 inch line fits snugly and the solder will have something to use as a backer...

Thanks you all for the input.

Keep the good idea's comming.

Here are a few more questions I have.
Where can I get the material to make the carb spacer, Granger?

Will plumbing solder/flux work?

Vapor lock is generally caused by too much restriction on the inlet side of the pump more than anything. It doesn't matter how big the pump either, return system or dead head. Often going to a steel mesh pre-filter before the pump and a paper filter after the pump fixes any vapor lock issues I normally see.

You can buy (or make) carb spacers that are phenolic or plywood, they are a big help. I just this week found that a Fram G12 fuel filter (or equivalent) is plastic and suitable for many 4 bbl mopars (5/16 inlet and outlet, flow through). I just removed my stock type metal filter (heat sink?), and will take it for its first drive with the plastic filter tomorrow. Will report back.

I would never use a plastic filter, too dangerous.

And the return line in the trunk like in the picture above is sloppy and also dangerous because something in the trunk could slide around and damage the line causing it to leak, I don't like it.

Here's my 50-year list of vapor-lock / percolation fixes, in no particular order:

> Carb isolator gasket (thicker the better)
> Carb heat shield plate ('Vette-like)
> Block heat crossover
> Vapor breaker (3-nipple) fuel filter. 3rd nipple on top, return to tank
> Elec fuel pump, as close to tank as possible. Best is hi-press pump, regulator right at carb
> Adequate tank venting and/or pressure-vacuum cap
> Dump mech pump, run hardline to carb close to firewall, away from exhaust
> Holley carbs: use Dominator bowls. Run return line, restricted to 0.050", from second inlet on each bowl back to tank (see pix).

I'm sure there's more, this is what comes to mind right now.

Rick

Thanks for all the advice, keep it coming.
I think that I will try adding Marine sta-bil too see if it helps for a quick fix, until I can add a return line.

Here is some good info on marine sta-bil

Ethanol: The good ,bad and ugly
is straight forward

http://www.goldeagle.com/engine_care/411onethanol.aspx

Its on its way

Time to get ready.

http://www.bloomberg.com/news/2010-10-13...html?cmpid=yhoo

The No_Politics administration granted a request from ethanol producers to increase concentrations of the corn-based fuel additive in gasoline for vehicles made for 2007 and later. Ethanol makers rose in New York trading.

The Environmental Protection Agency today agreed to let refiners add as much as 15 percent ethanol to a new blend, up from the current 10 percent. A decision on using more ethanol in fuel for vehicles in model years 2001 through 2006 will be made after further testing, the EPA said in a statement.

“This is a first step,” said Tom Buis, chief executive officer of Growth Energy, an industry trade group in Washington that promotes ethanol as a cheaper alternative to gasoline and a way to reduce U.S. reliance on foreign oil. “We know we have challenges we have to address.”

Archer Daniels Midland Co. is among producers that pressed the EPA to raise the limit for an industry that’s had at least a dozen companies seek bankruptcy protection since 2008. Oil companies, automakers and environmental groups say adding more ethanol may damage engines, boost food prices and worsen air quality, and refiners and convenience stores that sell fuel may be reluctant to market the new blend.

Archer Daniels of Decatur, Illinois, rose 51 cents, or 1.6 percent, to $33.22 at 4:15 p.m. in New York Stock Exchange composite trading. The company is the second-largest U.S. ethanol producer behind closely held Poet LLC, based in Sioux Falls, South Dakota.

Energy Ethanol Tests

A decision on the blend, known as E15, for cars made for 2001 through 2006 is likely to come in November after the Energy Department completes testing of those vehicles, according to the agency.

The EPA won’t raise ethanol concentrations for automobiles from 2000 or earlier because sufficient testing isn’t available, Gina McCarthy, EPA’s assistant administrator for air and radiation, said today on a conference call with reporters.

The No_Politics administration doesn’t have the power to order use of E15, though the decision has “the potential to increase the use of renewable fuels in the future,” McCarthy said.

Green Plains Renewable Energy Inc. in Omaha, Nebraska, rose 62 cents, or 5.5 percent, to $11.91 on the Nasdaq Stock Market. Pacific Ethanol Inc., a Sacramento, California-based producer of the fuel, rose 10 cents, or 10 percent, to $1.10. Aventine Renewable Energy Holdings Inc. rose 50 cents, or 1.9 percent, to $27.50 in the over-the-counter market.

No Refiner Requirement

Companies like ADM may not see an immediate boost from the EPA decision because refiners won’t be required to sell the new blend, said analyst Robert Moskow of Credit Suisse AG in New York.

“The approval of E15 by the EPA won’t have a positive effect on ADM in the near-term,” Moskow, who has an “outperform” rating on ADM shares, said in an Oct. 6 report. “Blenders remain reluctant to implement E15 because it requires a separate pump and because the EPA has not absolved the blenders of potential legal liability from consumers.”

Valero Energy Corp., the largest U.S. refiner, and Marathon Oil Co., the largest refiner in the Midwest, are concerned the new blend may leave them liable for engine damage, according to company spokesmen.

“Rushing through this new fuel standard without complete research may be good politics but is bad policy,” Bob Greco, director of downstream operations for the American Petroleum Institute, a Washington trade group, said today in an e-mailed statement.

Decision Delay

The EPA delayed its ethanol decision in December, saying the agency needed more time to test the blend. A decision was again postponed in June, prompting Growth Energy, which sought the E15 approval, to write to President Barack No_Politics expressing frustration with the process.

AAA, the nation’s biggest motoring organization, said in July 2009 the EPA should reject Growth Energy’s request because higher blends may damage exhaust systems, engines and fuel pumps and destroy catalytic converters. General Motors Co., Ford Motor Co. and Chrysler LLC have said the No_Politics administration should be cautious about increasing the ethanol percentage in gasoline.

“EPA has placed retailers in a very precarious position,” said John Eichberger, vice president of the National Association of Convenience Stores, which said it sells 80 percent of gasoline in the U.S. The group urged retailers to use “extreme caution” before selling E15.

Gasoline retailers will not be allowed to sell the blend until the EPA completes rules for gasoline-pump labels. Growth Energy’s Buis said E15 may be available to motorists in the first three months of next year.

Boat Engines Excluded

The decision excludes non-road engines such as boats and snowmobiles. The National Marine Manufacturers Association, a Chicago-based trade group for the recreational boating industry, said it’s worried that consumers may become confused and put the wrong fuel in boats.

“We are astonished that EPA has decided to move forward with a fuel that will increase air pollution and damage hundreds of millions of existing products,” President Thom Dammrich said in a statement today. The U.S.’s 66 million boaters will be left “holding the bag for performance issues and expensive repairs,” he said.

The Natural Resources Defense Council, a New York-based environmental group, said the EPA’s approval of the higher ethanol concentrations is risky.

‘Serious Risks’

“Though seen as a win for corn-ethanol lobby groups like Growth Energy, the new ethanol blends come with serious risks for our engines, wildlife, water and the air we all breathe,” Nathanael Greene, a renewable-energy policy analyst with the group, said today.

Growth Energy, which is headed by Wesley Clark, a retired Army general and 2004 Democratic presidential candidate, has said ethanol is 59 percent “cleaner” than straight gasoline.

Raising the “blend ratio” will boost demand, according to Growth Energy. By law, the U.S. must use 12 billion gallons of renewable fuels such as ethanol next year, up from 10.5 billion in 2009, and use 15 billion gallons by 2015.

The annual market value for ethanol in the U.S. has risen to $27.1 billion since federal support began under President Jimmy Carter during the 1970s energy crisis.

The U.S. pays a 45-cent tax credit to gasoline refiners that make a blend of as much as 10 percent ethanol, an incentive that is up for renewal at the end of this year.

To contact the reporters on this story: Kim Chipman in Washington at kchipman@bloomberg.net; Mario Parker in Chicago at mparker22@bloomberg.net

To contact the editor responsible for this story: Larry Liebert at lliebert@bloomberg.net.

http://mystarbrite.com/startron//content/view/14/37/lang,en/
I think that i'm going to try this stuff.
Available at Walmart

Ethanol/E10
The Star Tron® Ethanol Story

Ethanol or E10 fuels attrack moisture (water) through the atmosphere in your fuel tank. Water molcules combine with the ethonol molecules creating a new water/ethanol molecule that is heavier than the fuel so it is dragged to the bottom of the tank. This is known as phase separation. it creates a corrosive layer below the now substandard fuel. Star Tron Enzyme Fuel Treatment works to break up the bottom layer so it burns up or filters easily.The sale of ethanol blended fuel, commonly referred to as E-10 gas, is on the rise in the US as more states are mandating its use. Also promoting the growth of E-10 is the need to phase out the current additive MTBE which has been found to contaminate ground water supplies. E-10 gas has been in use for many years and, with smart fuel management, most
of its negative issues can be resolved.



The first problems encountered with transitioning to E-10 is the loosening of sludge from the fuel tanks. Ethanol is a very effective solvent and it will attack varnish, gum, and resins - the sludge that can build up in fuel tanks. Once cleaned off the fuel tank walls this build-up leads to poor performance and frequently clogged fuel filters and injectors. The enzymes in Star Tron® will safely break down and disperse this sludge. After a filter change or two the fuel tanks will be clean and you can focus on the next, more serious, ethanol related issue.



In addition to a loss of power and economy, E-10 can cause other problems. Ethanol is hygroscopic, meaning that it will attract water from the air, which is absorbed into the gas. The water bonds to the ethanol, becoming heavier than gas and the mixture sinks, lowering the octane level and causing performance problems. This is Phase Separation. Cold temperatures will accelerate this separation. Ethanol is also a potent solvent that will loosen old gum and varnish deposits, which can darken the fuel and foul filters and fuel injectors with large particles. The mixture of ethanol, water and particles can form a gelatinous sludge layer on the tank bottom that can block filters and damage your engine. During operation, Star Tron’s® powerful enzymes allow water to be dispersed throughout the fuel as sub-micron sized droplets that are safely eliminated as the engine operates. They also slowly break down the sludge, cleaning out your fuel tank while restoring the fuel’s combustion characteristics to insure proper and safe engine operation.



In a boat, motorcycle, outdoor power equipment or other gas-powered equipment that is being used regularly, Star Tron® can help prevent phase separation that occurs from daily condensation. By neutralizing the electrical charges between water molecules in a process called de-ionization, Star Tron® prevents the water molecules from forming huge clusters large enough to form drops and settle, taking the ethanol with it to the bottom of the fuel tank. The octane rating and the combustion characteristics of the gas are protected, and the suspended water molecules are harmlessly eliminated along with the fuel. In order to understand this process, start by understanding that water does not exist in nature as its textbook single molecule, (H2O). Water consists of hundreds of water molecules bound together in huge “macroclusters” which are much larger than a fuel molecule. Star Tron®’s enzymes break the electric bonding that holds these macroclusters together, reducing the molecular size of the water cluster sufficiently to where microscopic amounts are suspended harmlessly in the gas.

A new breed of fuel additives has recently cropped up to capitalize on ethanol-blended fuel problems. These additives are known as emulsifiers. Ironically, some of them are made from ethanol or isopropyl alcohol or one of the many alcohol cousins. Some emulsifying products will use chemicals such as “ethanolamides” (or anolamides), which are basically just common detergents.



Alcohol has been used by boating consumers for years to “dry” out gas, but that was when gas was 100% gas. E-10 already has a huge amount of alcohol in it, and adding more can cause operational problems and increase the water problem. Adding additional alcohol can also violate the EPA regulations on limits of oxygenates (alcohol) allowed in the fuel, as well as the ASTM fuel specifications. The EPA sets those limits to prevent damage to the engine. Today, all engine manufacturers have certified their new engines to operate on a maximum of 10% ethanol. Any additive taking the fuel over 10% alcohol may void your warranty.



Before using a fuel additive, review the Material Safety Data Sheets (MSDS) provided by the manufacturer to determine if it contains any alcohols or other harmful water-bonding components. Adding more alcohol to E-10 fuel is not the solution and in fact can compound the problems as emulsifiers have a long history

of causing engine damage. These additives have the ability to absorb their own volume in water, thus allowing more macro water clusters to bond with the fuel. Several of these “new” additives have been demonstrated via a neat sideshow trick in which water is added to gas in a test tube. The two fluids separate, and by adding the emulsifier and violently shaking the test tube, the water appears to vanish, but in reality the water still exists. What emulsified water can do to an engine can be far worse than the original problem. Water, when sucked into an engine in volume, can shut it down. It must be cleaned, and the oil changed, but little else happens. Emulsified water/ethanol causes a more serious problem because instead of shutting down the engine, the mixture can be partially combusted, but not effectively, which can damage the engine. Therefore, a mixture of water and ethanol is worse than just water. When emulsified water runs through an engine over a period of time, it causes excessive abrasion and wear, corrosion, and the emulsifier alone causes excessive carbon deposits, leading to wear on rings, pistons, and valves.



Emulsified water in the fuel can have several negative effects. Water displaces gasoline, which lubricates the fuel pump. Water pits and corrodes the plated metal surfaces causing premature wear on the fuel pump. Water reacts with various components in the fuel and forms acids, which corrode the fuel injector tips as well. Water/gas emulsions were tested by the SAE with ethanol and were found to remove the plating from fuel pump internal moving surfaces. (SAE 2005-01-2196, Rovai, Tanaka, Sinatora)



This is just the effect the wetted fuel has. The real harm comes during combustion. The earliest reference to experiments with gasoline and water emulsifications (water chemically bonded to an oil is called an emulsification) we know of dates from 1913. Ever since then, products have been introduced that claim to eliminate water from fuel. Many attempt to do so by adding an emulsifying chemical to gasoline. General Motors conducted a significant amount of research on this issue in the 1970s, and additional attempts were conducted for several years after. Each time, the deleterious effects of water/gas emulsions greatly outweighed any benefits gained.



Water emulsions immediately increase the fuel’s viscosity. Even “microemulsions” that appear to be clear and stable as opposed to the milky look generally associated with oil/water emulsions, still thicken the fuel. Thickened fuel can destroy a fuel pump and fuel injectors. The ASTM specifications for fuel viscosity are very tight; thickening the fuel with water can take the fuel outside its specifications, which will void a warranty. How thick is thick? You can’t tell in the field by looking, unless the emulsification has turned to gel, which can happen if there is an overdose of the emulsifier. The average consumer cannot be expected to dose with an emulsifier for a water level he can’t assess and be certain his fuel is still within approved specifications.



Because the emulsified water lowers the flame temperature in the combustion chamber, the combustion efficiency is greatly reduced and the amount of unburned hydrocarbons soars. This forms carbon deposits in the engine, especially on the piston crowns and on the spark plugs. Further, in the General Motors tests, (SAE 760547, Water-Gasoline Fuels, Their Effect on Spark Ignition Engines Emissions and Performance, Peters and Stebar) the deposit buildup was so rapid that the engine had to be disassembled for cleaning approximately every 20 hours. Additionally, they found shiny black deposits linked to the emulsifier and noted that the spark plugs were coated black and appeared wet. Drivability plummeted as well, and fuel economy suffers in a direct ratio to how much water is in the fuel. All negative effects increased as the water level increased. Eventually, GM abandoned their efforts with water in gasoline, as have many others over the years. It was also noted in the GM study that they did not bother to investigate the lubricity issues or long-term engine durability because the performance characteristics were so bad.



Star Tron®’s various enzymes will actually de-emulsify water, which is the correct way to treat contaminated fuel. The advantage to removing water in microscopic amounts is that Star Tron®’s enzyme technology is totally harmless to an engine and does not change the ASTM specifications for fuel. Star Tron® will not remove water from a glass jar but it will remove the water layer in operational boats, cars, ATVs, motorcycles or outdoor power equipment. The real Star Tron® advantage goes beyond just how it eliminates water, or even how it cleans up sludge. Star Tron® is also a combustion catalyst that reduces emissions, including deadly carbon monoxide, while it increases power and fuel economy. Star Tron® removes combustion chamber carbon deposits, reducing an engine’s octane demand and eliminating engine knock, as well as cleaning the entire fuel system. Star Tron® breaks down and safely disperses gum, sludge and varnish, and it outperforms conventional chemical-based gas stabilizers because in addition to slowing the aging of fuel (gasoline and diesel fuel can be stabilized for up to two years), Star Tron® can also rejuvenate stale fuel, restoring it to serviceable condition. It can improve octane in old, sub-standard or non-spec gasoline. It does all this at the lowest cost-per-gallon-treated of any additive.

I've just used Star tron for the first time in my boat, jury is still out. But understanding how E10 attracts water and seperates, it seems at a minimum, stabilizer is now mandatory in carb'd engines that will sit for weeks or months between uses.

My vapor lock problem actually turned out to be a Vacuum lock problem. I had added a new locking gas cap (at the same time I swapped motors, bad idea) that was not breathing properly. After running for 20 or 30 minutes, fuel pressure would drop and underhood temps would rocket. The vacuum lock was causing the low fuel pressures and forcing a lean condition that was making the engine really hot. Put the old gas cap back on, and fuel pressure is up and underhood temps are way down. Was pulling my hair out. (my emotions in a nutshell as I came to understand the problem)

My gas cap isn't the problem (it don't seal, its the original). But a good thing to check in the battle of vapor lock.
The Nov,25 2010 issue of Old Car Weekly, in the Q&A page, Hard starting was addressed.
The electric fuel pump was mentioned with mention of a bypass with check valve that is around the mechanical pump. Someone else states that they add a gallon of diesel fuel to each fill up.
Any one have any more info on the two of these remedies?