Vapor Lock, again

[1937pickup]

After reading Admirals post about vapor lock I did a little research on the web. Rather than post the results of my research in the original post I thought I would start a new post. I found page 2-3 particularly interesting. The author states that ethanol is nearly impossible to cause vapor lock-it is the gasoline. One other thing-gasoline varies in composition from tank full to tank full. Here is a link to the article, it is eight pages.

http://www.txideafarm.com/ethanol_fu...s_and_data.pdf

[39portlander]

Good topic and would like to review that info however, there is a security problem with that link. I tried to download what you got there and an alert immediately popped up.

This would be a great thread, try to find a download that has been checked for viruses.

[Ross F-1]

No problem on my computer. Here's the document

[1937pickup]

btt

[Admiral]

Very interesting read! I guess ethanol gets blamed for more than it deserves.

[scicala]

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The part I don' understand is why vapor lock and percolating fuel in carburetors sure seemed to increase since ethanol has been used in gasoline. If gas is the culprit and not the ethanol, what has changed in the gas to cause this ?

Sal

[Charlie ny]

Percolating fuel in a carb is even older than me......yikes.......I do believe gasoline
producers added certain additives for summer driving to somewhat arrest this
problem back in the day.
Charlie ny

[JT FORD]

I didn't open the link, anyone that states ethanol cannot cause vapor lock might
load the article with virses. Ethanol will boil at a lower temp that gasoline and it has and will cause vapor lock. It would not happen all the time but with right conditions it will happen!

[johnh7]

Ethanol, Boiling point 173.1°F (78.37°C)

Gasoline has an initial boiling point of about 35 °C (95 °F) and a final boiling point of about 200 °C (395 °F)

Gasoline boils at a lower temperature than Ethanol. Ethanol does raise the boiling point of gasoline. Facts are facts.

Various Fuel Boiling Points listed below

Acetaldehyde 70
Acetone 134
Acetylene -119.2
Benzene 176.2
Butylene 21.2
Ethyl Alcohol 172
Ethane -127.5
Ethylene -154.7
Fuels Oil No.1 304 - 574
Gasoline 100 - 400
IsoButane 10.9
Isobutene 19.6
Isopropyl alcohol 181
Iso-Octane 243.9
IsoPentane 82.2
Kerosine 304 - 574
Methane (Natural Gas) -258.7
Methyl Alcohol 149
n-Butane 31.1
n-Heptane 209.1
n-Hexane 155.7
n-Octane 258.3
n-Pentane 97.0
n-Pentene 86.0
Naphthalene 424.4
NeoPentane 49.1
NeoHexane 121.5
Propane -43.8
Propylene -53.9
Triptane 177.6
Toluene 231.1
Xylene 281.1

Just FYI

[Lawrie]

I can sure relate to the difference in quality of fuel,we are away in the 33 towing our 900 kg caravan.
One day we can burn along alday at 55-55 mph no probs,fill up and straight away notice a difference in performance,specially when accelerating over 50 mph,next fill up back to normal.
Lawrie

[ford38v8]

Lawrie, the example you describe appears to be a clear case of upside down fuel.

[G.M.]

Originally Posted by scicala

The part I don' understand is why vapor lock and percolating fuel in carburetors sure seemed to increase since ethanol has been used in gasoline. If gas is the culprit and not the ethanol, what has changed in the gas to cause this ?

Sal

I never checked the boiling point of gas but did with ethanol which I posted the results on Ford Barn. Carb percolation and vapor lock in the fuel pump have nothing to do with each other except both are heat related. The carb problem normally happens after the engine is shut down. Pump VL occurs
at idle or low speed when the fuel pump gets hot, at idle and low speeds the fuel remains in the pump to long, at higher speeds more fuel is being used so more fuel is flowing through the pump cooling the pump with cooler gas from the tank. I haven't had VL using non ethanol gas. G.M.

[Vic Piano]

I fixed the Vapor Lock problem in my two '39's, my '47 and my '51 F-1 by installing electric fuel pumps as the only fuel pumps. It works for me!

[G.M.]

Originally Posted by Vic Piano

I fixed the Vapor Lock problem in my two '39's, my '47 and my '51 F-1 by installing electric fuel pumps as the only fuel pumps. It works for me!

I don't like electric fuel pumps. Fixed mine with a 1/8" return fuel line. G.M.

[Vic Piano]

George, your mechanical aptitude and patience far exceed mine. I admit that I took, what I perceive to be, the easy way out.

[bobH]

George, How did you 'tap-in' for the return line. Only way I've thought of, is to use a filter that has the provision, for example the filter that is used on stock 83-85 CJ-7 Jeeps comes with a return line nipple (and the nipple has a built-in orifice). Have you come up with another way?

[G.M.]

Originally Posted by bobH

George, How did you 'tap-in' for the return line. Only way I've thought of, is to use a filter that has the provision, for example the filter that is used on stock 83-85 CJ-7 Jeeps comes with a return line nipple (and the nipple has a built-in orifice). Have you come up with another way?

I put a "T" in the metal fuel line right after the pump. I first put a needle valve after the "T" so I could adjust the return flow. Later removed the valve and put a small orfice hole in the return line if I recall it was about the size of the hole in the Stromberg needle valve hole .098 with the orfice hole it don't matter what size return line you use as long as it's at least 1/8th inch ID. G.M.