Some of my V-8 buddies are heading for the V-8 Nats in Tahoe. They are having severe vapor lock issues in the 100 degree heat out west. I offered all I can think of, any ideas!!!
A pusher pump. Not sure what kind of pressure they need, but Facet makes a wide variety of little pumps. The range is 2 lbs on up. Use that insulation tube stuff as well. The Facet pump solved my issue though. They used to be about $20 or so at NAPA
I use this stuff on fuel and brake lines that p*** near heat to keep the fluid cool and heater hoses cause it looks good imo. It's expensive, but it works very well and a roll goes a long ways. The extra can be sold to your friends to recoup the cost. I seal the ends with heat shrink tubing. http://www.cableorganizer.com/insultherm-braided-sleeving/ It's on the heater hoses coming out of the water pump on the left -
clipping the clothespins onto the fuel lines gives you something to do while you are stuck on the side of the road waiting for everything to cool off.
I see lots of stuff about vapor lock on the net. Every car I have ever owned has had a carburetor and mechanical fuel pump. Every place I've lived gets up over 100 degrees in the summer. I have never had vapor lock. Maybe I'm lucky but , I just don't get it.
I don't have the foggiest,Magic? I'm guessing they create a cooler spot on the line,,possibly the metal spring soaks up some of the heat? Whatever the reason,I had a flathead as a kid my granddad showed me the trick on a extremely hot day after my car vapor locked and I road around with 3 cloths pins on the fuel line for the next 2 years,,never locked again,,looked goofy but worked. HRP Post a intro funny guy! HRP
One thing that often gets confused with vapor lock is a poorly vented fuel system. The next time it stops, run and pop the cap. If they hear air rush into the tank, It's a vent issue. I have seen several old vented caps that don't vent right. If the fuel pump doesn't have enough suction, it can't pull through the weak vent and eventually stops moving any fuel. I only mention this because it gives the same symptoms as vapor lock but is much easier to fix (new cap, clear the mud dobber nest out of the vent line, etc). A pusher pump is a good bandaid for vapor lock if you are stuck on the road but moving and insulating fuel lines is the real longterm fix.
It mat be blatantly obvious, but keep the fuel line going to your carb well away from any heater hoses. It was the cause of some vapor lock issues I had before switching to an electric fuel pump. The inline fuel coolers also help. You can hide them under a frame rail if needed. Also, a return fuel line is not a bad idea if you have regular vapor lock issues. It keeps the fuel circulating, and thus cooler.
The clothespin trick absolutely works. It acts as an insulator, shlielding the fuel line from heat. We had a Ford stock car that was prone to vapor lock, my racing partner at the time whipped out the clothespin trick.. and it worked. Before the feature, he would line them all up the same way on the fuel line just for esthetics. Bob
Back in my drag racing days,just used a coolcan and eliminated the problem,especially with the big block Mopars which have vapor lock problem more than Fords and G.M..
I have suggested all of the above, so we are all on the same page, even the close pins. The cars are original '32 flathead Fords so they are limited to what they can do to the fuel lines. Hopefully with all the suggestions they will make it to Tahoe. Thanks for all your suggestions!
Back in the day some friends of my dad were having vapour lock problems somewhere in the mountains in southern Europe. Nobody knew the language but eventually they managed to understand what a police officer suggested they'd do: pour cold water over the fuel pump. Worked well for them, and should get you going quicker than just standing around waiting for everything to cool down.
Clothspins do work I work at a gas station guy run all day long spreading fert. no problem every other trk. would just stop vapor lock he used clothspins it does work Rog.
I've heard of this, too. 10% diesel, 90% gas. Haven't heard a suggestion of a return line to the tank yet. Put a tee at the carb (may need to use a reducer of sorts like a 1/32 orifice to limit flow in case of a weaker fuel pump) and plumb it back to the tank. The gas circulating and moving keeps it cooler. Remembering that higher elevation, the lower the atmospheric pressure, the lower the boiling point, makes a fix before a trip to Tahoe a good idea.
Laugh all you want to about the clothes pins but they work. 49 to 54 Chevys were bad about this as the fuel line came up and around the front of the head. Pop one or two clothes pins on at the front of the head and you were good to go. Have used a lot of them. But this is old school and as you know all us "old guys" don't know a thing. Just ask one of the younger kids and they just snicker about things like this. They have never had to make do with what you had. Hell, I remember a 54 Chevy wagon a friend of mine had that we ran on 5 cylinders for months before we could save up enough to buy another engine. Pulled the rod and piston pulled the rockers and push rods, presto a five cylinder. Down side, shook like crazy and would run hot. We just kept 3 five gallon cans in the back and would run it till it boiled pour in the water and go again.
I'm a big fan of diesel in the gas. Generally a quart in a tank will do the job. Smell the $4.99 fuel injection cleaners. Petroleum distillates. Its diesel.
as far as the clothes pins go, they are available in chrome, red.black, blue, or in some cases custom colors! lol, i remember when i was about 15 years old i was given a 49 ford, with a flatty, it had clothes pins all over it! i always carried a jug of water with me to pour on pump. it would usually always started with the water, if i didnt run the dam 6 volt battery down! ha!
With the weather getting hotter there always seems to be more mentions of older cars having vapor lock problems. Most of the recommendations for fixing the problem are correct, especially the addition of an electric fuel pump near the tank and making sure that fuel lines are routed away from exhaust and other heat sources. Too much heat and the fuel percolates in the fuel lines. But keep in mind that technically, vapor lock only occurs on the suction side of the fuel pump. By design, mechanical fuel pumps are primarily made to pump only liquid fuel. They are less suited to pumping air, and this is a particular problem on the suction side of the pump. Air in the pump inlet line is compressible and the pump pretty much just compresses and expands this air without actually moving much liquid fuel into the pump. And it only gets worse if it's an old pump that's not working up to specs anymore. On the outlet side of the pump, the pressure side, a bit of air in the fuel line is much less of a problem. If there is liquid fuel going into the pump it's very easily pressurized and will push fuel, and any air bubbles, thru the pump outlet pipe and on up to the carburetor. It's still a good idea to keep these lines away from heat sources, and maybe add an insulator or heat dissapater to the base of the carb. But heat issues on this side of the pump cause a whole different set of issues like fuel percolation, flooding and gas escaping from the carburetor vent tubes. So to help draw heat away fom the fuel lines, things like clothes pins and aluminum foil work like heat sinks to help draw heat away from the lines. Think of the cooling fins on a radiator, an air cooled cylinder, or electronics components. Maybe I need to invent a polished aluminum clothes pin. Heat isn't the only cause of air getting into the suction side of the fuel lines. Also check the steel lines and rubber hoses for good connections, holes, rust perforation, splits and cracks. You won't necessarily see any fuel leaks or smell gas since this section of line is normally at atmospheric pressure or under a slight vacuum. A hole can let air enter the line without allowing fuel to escape.
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