Vapor Lock

Do a search.....this has been discussed over and over, with many different thoughts. Not all agree it even really exists. Kind of like which oil is best!
 
Benson said:
I see that it is 85 F in Coral Springs, Florida right now.



1. Does car have Winter gas in the tank?



2. Was car last filled with gas from a northern state in winter time?


If so that gasoline has a high Reid Vapor Pressure designed for winter temps and it will boil at at temps above 65-70 and vapor lock.


3. Drain tank and put FRESH gasoline in tank and try it again.


4. Gasoline with greater than 15% ethanol will be worse.


FYI: That gasoline should work just fine in a fuel injected / computer controlled engine.
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Yes, it's hot in Fla., owned the PicUp 2 1/2 years, and it began this two months ago when the weather was cooler. Driven three times a week, and I do expect it's the quality of gasoline too. Why it waitted this long has me concerned -- makes it dillicult to depend on, it's a blast to drive. I've allready did a search here, but most are related to cars with original fuel pumps, so, wondering if a 2 pound fuel pump would be of any help. Right now looking to insulate the lines/carburator -- somehow.
However, have used the same gas station since bought PicUp

Thanks
 
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I use a foam beer can cooler and slip it over the sediment bowl. Cheap and 5 minutes to hook up. No sense thowin money and tearing stuff apart. I used a thermal heat gun and measured the temp of my carb against two other "A"s in 100 Plus degree heat. I ran 20 degrees cooler at the carb.
 
I use 4 wooden close pins clipped on gas line close to carb. Its worked for years for me and a lot more that have tried it.
 
DBrer said:
Do the clothes pins act like a heat sink?
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Yes, wood is generally thought of as an insulator and not as a heat sink.


rfitzpatrick said:
What's my solution for vapor-lock -- thanks
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Is your condition vapor lock or fuel percolation? Two totally different issues.

One thing to consider in all of this is, most cheaper riding lawnmowers use the same gasoline as what we use in Model-As, and they are also gravity fed fuel systems. They do not suffer from percolation or vapor-locking issues even on a 110° day in July when mowing 2' tall grass. So what is the difference?

The key I think is airflow. I have been on tours where we all filled up at the same gas station, and have the same type carburetor yet someone was complaining about their engine was vapor locking its fuel and mine/others wasn't. The biggest difference I could see was I had engine splash pans on and he didn't. Maybe there was other contributing factors, but that is some observations. Also, a vehicle that has bad grounds will sometimes use the fuel line as a ground. That can also heat fuel flowing thru the line.
 
BRENT in 10-uh-C said:
Yes, wood is generally thought of as an insulator and not as a heat sink.




"Is your condition vapor lock or fuel percolation? Two totally different issues."


When it'll happens, we pour water over the carb/fuel line and it's temportarly corrected itself until it happens shortly afterwards. Have no sucess wraping the fuel line in an insulation either. Once while I was running the engine, I saw an air bubble form rigth there in front of me in the fuel bowl, while the engine was running -- tho a bit rough. We've noticed the fuel line has a very short distance where the line runs parelle on the way to carb., and looking into making this distants go away

Would inserting that fuel line is say a rubber hose (vacumn line?) offer any assureances, watse of time, or what? Would (and I hate this one) going with a rubber fuel line solve this?
Thanks Guys
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I use a cast iron fuel bowl--- have never seen a bubble in it
When the metal fuel pipe was cut to length with a cutter the burr left constricts the end--- similar to the crimped over end of the hamsters water bottle--- ream the ends to the diameter of the pipe
Get rid of paper filters, use original screen
Make sure there's no low spots in the fuel pipe-- all downhill to the carburetor---- it's working for me
 
I agree with Brent, splash pans are a must, They aid in venting out hot air under the hood, otherwise, the hot air just swirls around with fan air and undercarriage air fighting each other while going down the road. My '31 truck is original to a point with splash aprons, original fuel line set-up, glass bowl with screen filter, orig. carb, etc... I have never had vapor lock or overheated on some of our hottest days on a long trip.
 
In the late 40's and early 50's my brother and I had a '31 coupe. It was stock and had no engine pans. We drove it just like any 15/16 year old boy would. Proved how tough these cars are. It was driven over the streets of Dallas in summer and winter and it never percolated the gas.
I have 3 Model A's and my son has 3 and at one time or another they have all had the problem of percolating gas. We go on tours with our Model A club through out the summer and on any given day many cars have the problem. But there are days when the same car that had trouble yesterday has none today.
All the "fixes" mentioned over the years for the problem have produced little or no effect to prevent it. We have tried them all.
One thing we have done that seems to have some effect is to change the fuel line from the fuel bowl to the carb. to a steel 5/16" line. The theory behind this is the larger line will allow more fuel to flow along with the percolating condition thereby allowing the engine to keep running. Seems to work.
The best fix so far is to purchase ethanol free gas wherever available.i.e. some Walmart Super stores, etc.
 
Make sure there's no low spots in the fuel pipe-- all downhill to the carburetor----




This is being addressed. Engine bay has Splash-Pans since purchased.
Asking club mechanic to look at the valve gap tomorrow.
Thanks Everyone
 
How clothespins work in curing vaporlock:

1. Clip about 20 all along the fuel line. The metal spring kind work best.
2. Drive 'till you get vapor lock, then coast over to the side of the road.
3. String a 1/4" rope tightly between two trees.
4. Find the nearest creek, take your clothes off and wash them.
5. Use the clothespins to hang your clothes out to dry.
6. After drying, put your clothes back on, coil up the rope, replace clothespins on fuel line, close the hood, start the car and drive away.
7. If the car vapor-locks again repeat 1-6.

WORKS EVERY TIME !
 
MikeK said:
How clothespins work in curing vaporlock:

1. Clip about 20 all along the fuel line. The metal spring kind work best.
2. Drive 'till you get vapor lock, then coast over to the side of the road.
3. String a 1/4" rope tightly between two trees.
4. Find the nearest creek, take your clothes off and wash them.
5. Use the clothespins to hang your clothes out to dry.
6. After drying, put your clothes back on, coil up the rope, replace clothespins on fuel line, close the hood, start the car and drive away.
7. If the car vapor-locks again repeat 1-6.

WORKS EVERY TIME !
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I actually read this !!
 
I hate to admit it but so did I.:rolleyes:
I've driven my A for hundreds of miles at a time in 100+F temperatures (very uncomfortable) with no engine pans and never had a problem with fuel supply.
 
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