Vapor Lock

[RobR'35]

Reading in Dick Flynn's tec tips. April '84 there's mention of drilling a hole in the pump body to prevent vapor lock.
Anyone have a diagram of this and also has anyone done it?
Im interested on the feed back of this curious idea.

[keith oh]

No, but I have some Ford Logo clothes pens. Grinn

[JSeery]

Originally Posted by RobR'35

Reading in Dick Flynn's tec tips. April '84 there's mention of drilling a hole in the pump body to prevent vapor lock.
Anyone have a diagram of this and also has anyone done it?
Im interested on the feed back of this curious idea.

Vapor lock is the result of lowering the pressure on the fuel (because of the action of the pump diaphragm) and elevated fuel temperature. Once you exceed the vapor pressure of the fuel it starts to transform from a liquid into a vapor which does not pump or meter well. Not sure how drilling a hole anywhere is going to change the pressure drop required to move the fuel or reduce the fuel temperature (if what he was referring to was actually vapor lock).

[Lawson Cox]

Originally Posted by JSeery

Vapor lock is the result of lowering the pressure on the fuel (because of the action of the pump diaphragm) and elevated fuel temperature. Once you exceed the vapor pressure of the fuel it starts to transform from a liquid into a vapor which does not pump or meter well. Not sure how drilling a hole anywhere is going to change the pressure drop required to move the fuel or reduce the fuel temperature (if what he was referring to was actually vapor lock).

With all respect to Dick Flynn, some of his tips are as though he had pulled them from his nether regions. This seems to be one of them.

[ford38v8]

Originally Posted by Lawson Cox

With all respect to Dick Flynn, some of his tips are as though he had pulled them from his nether regions. This seems to be one of them.

X2, 3, 4, ad infinitum....

[RobR'35]

Sponsored Links (Register now to hide all advertisements)

Its the reason for me asking the question. Seems odd to me.

[Old Redneck]

Electric Fuel Pump is the only answer. Cars today have the fuel pump inside the gas tank to prevent vapor lock.

[WestCoast]

vapor lock? don't you guys ever read the posts on here by the experts that tell you there is no such thing as vapor lock, its an electrical problem, no matter if you quickly get out of your non running car and check spark to the plugs and find there is fire there, and if you work the throttle rod to the carb and no gas squirts down the carb throat, its an electrical problem, never mind the facts, you have hot spark to the plugs and no gas in carb with a full tank of gas, LOL

[Lawrie]

I have seen on early Holden fuel pumps a small hole between the delivery and suction side of the pump.this is about 1/32 dia.
Lawrie

[scooder]

Originally Posted by Redneck

Electric Fuel Pump is the only answer. Cars today have the fuel pump inside the gas tank to prevent vapor lock.

A gas return line from pump will also work. Manufacturers started using them in the early 60's, this eliminated vapour lock by keeping cooler gas going through the pump. You don't need an electric pump.
Modern cars have the pump in the tank as there running high pressure fuel injection, and submursing the pump removes the need for an extra swirl pot pre pump. Not because of vapour lock.
Martin.

[G.M.]

Originally Posted by scooder

A gas return line from pump will also work. Manufacturers started using them in the early 60's, this eliminated vapour lock by keeping cooler gas going through the pump. You don't need an electric pump.
Modern cars have the pump in the tank as there running high pressure fuel injection, and submursing the pump removes the need for an extra swirl pot pre pump. Not because of vapour lock.
Martin.

I put a SMALL return line after the pump in the carb fuel line back to the filler neck on my 39. No more vapor lock. The line needs a restrictor hole in the return fitting of about .110 to control the amount of returned fuel. To much return will not allow enough fuel at higher speeds, not enough fuel returned will allow vapor lock. I can look in the fill neck and see how much fuel is being returned. G.M.