Vapor Lock question

RonS

Oh! summer in Arizona. I took Herietta(my 53 HH coupe) for a drive yesterday.She drove very well. Showed it a local retirement community.On the way home the air temp went over 95F usually about 5 degrees into the "use electric fuel pump" time .Any way a few years ago Walt Mordenti ran an article in the WTN decribing a fuel feed back system using ,I believe , a Chrysler type gas filter. Are there any opinions and what is the filter #.I don't like to use the electric pump(rotary style)while constantly driving.I fear that if a needle valve sticks on the twin -H I'll dump gas all over while cruising along. I have a switch set up to shut down when the Ignition is off. I would prefer to just use the pump to prime. Also pressure regulator is in line.Mechanical fuel pump and electric are on independant fuel lines.Car runs great in any temp with electric running,but I feel there must be a way to not need the electric even with this crap gas. By the way AACA now allows electrics on pre war cars. Interesting.

[Deleted User]

Walt Mordenti here. To solve vapor lock go to page 39 in my tech tip book. It tells how to install a fuel return line and that will always keep cool gas in the pump. Vapor lock is because gas boils in the pump. If anyone that doesn't want to do this connection just carry bottle water and if vapor locked just pour water on the pump and your car will start right up. Through trial and error I had an add on which I sent to all when they bought my book. If you have my book but not the add on e-mail me and I will send it to you. One more thing, clean all paint off the top tank of your radiator for this is good for 10 degree temp drop.

[Deleted User]

walt's garage-53 wrote:

Walt Mordenti here. To solve vapor lock go to page 39 in my tech tip book. It tells how to install a fuel return line and that will always keep cool gas in the pump. Vapor lock is because gas boils in the pump. If anyone that doesn't want to do this connection just carry bottle water and if vapor locked just pour water on the pump and your car will start right up. Through trial and error I had an add on which I sent to all when they bought my book. If you have my book but not the add on e-mail me and I will send it to you. One more thing, clean all paint off the top tank of your radiator for this is good for 10 degree temp drop.

Hi Walt---How does one get a copy of your hints book? Hudsonly---Cliff Minard.

harry54

Marvel Mystery oil works also. 8 oz per tank full.

duncan

Add 1/2 qt 2cycle engine oil to each tank full of gas works awesomly,

RonS

Walt,I was not aware that you had a tech manual either.Actually my car doesn't stop running it starves for fuel and begins to hesitate and surge giving me warning to turn on the electric pump. Once the pump is running for a moment all is well.I presume that this is the forerunner to vapor lock, or not? My temp does go up at idle like waiting for a traffic light but drops back once I'm under way .I have a infrared temp digital gauge and it reads 160-180 degrees at the thermostat , but the mech fuel pump goes to 156 degees as well .I believe that is too hot.Fuel line before pump is 12 in of rubber line But the line to the carbs is steel and rapped with header cloth. I poured water on the pump to no avail.Ron

[Deleted User]

You are starving for gas. You have a restriction in you gas line. Disconnect the line at the tank and have someone hold a rag over the end of the line and blow air, at least 50 lbs, to see if dirt comes out, if yes your tank will have to be cleaned. If clear then your fuel pump is starting to go. Hook a pressure gauge to the line that goes to the carb and see how much pressure you are pumping, need 41/2 to 51/2 pounds. Your temp is right and vapor lock will shut your engine down. Walt.

[Deleted User]

I sold out 2 prints of my tech book and am now making a new print to cover 2004 to 2007. I will also make a new print of my 1995 to 2003 tech book. When done I will advertise in the WTN and 6 Chapters. It will be in the Literature section. Walt.

hudsonguy

Three books you need to have when taking your Hudson on a long road trip. 1) HET Roster, 2) Hudson Shop Manual and 3) Walt's Tech Tip book. That book has helped me more times than I can count. Walt, I'll be one of your first customers for the latest version!

RonS

Yea,me too Walt .Thanks. Not too sure about blockage ,'cause if I disconnect the gas line before the electric pump (about the area of the B pillar,low point of the fuel line) the gas will pour out in a strong steady stream. At that point I have a Tee sending fuel to either the mech. pump or straight to the tee beyond the mech. pump right to the carbs, But the mech. pump could be weak. How many gaskets are recommended for the mech pump? I wonder if I'm not getting enough movement from the cam actuating arm.

[Deleted User]

You need the spacer that Hudson installed between pump and block. Bill Albright did make an aluminum spacer or contact Dale Cooper to get one. It's about 1/4 inch thick. All remember, vapor lock will shut your engine off. If you get a surge it's because you are starving for gas. Install see through filters and you can always check for dirt because filter element will turn dark brown, time to change. Walt. I'm having my first book reprinted to be follow by the new one, 2004 to 2007.

RonS

I checked the pressure on the carb line with the mech pump4.75 PSI then the electric just a hair higher But thes rotary pumps come with a small brass filter that seems to restrict the fuel flow more than the plastic paper filters or the cartrage in line type.Also the filter is common to both lines,so any restriction might cause the said effects when the engine is stressed out. Still like your idea of a fuel feedback line.Ron