Vapor Lock or Heat soak the carb no mo' !

[Conroe Powdercoating]

My car starts beautifully cold, fires right up, but when hot, it was always a nightmare. If you stopped at a corner store, run in and buy a soda pop and it wont start. I always thought it was flooding out, but real world, it was vapor locking.

My car (51 cranbrook) has the heat shield over the fuel pump, I wrapped the exhaust manifold in the fuel line area with insulate wrap. I even wrapped the metal fuel line itself from the pump to carb bowl.

All of that made a big difference, but not just right still when hot at operating temp. (My car never overheats, this is at normal operating temps, it is Texas).

I made a simple heat shield that fit over the intake runner and goes under the carb bowl, this plate stops the heat from rising straight up and percolating the fuel in the bowl when the car is stopped and no air flow under the hood. This mod made ALL the difference in hot start issues, which, I have NONE now. The car fires right up, now I have to learn it likes one tap of the throttle and one tap only :-)

 

Edited July 6, 2014 by Conroe Powdercoating

[Don Coatney]

As has been discussed many times vapor lock only occurs when the engine is running. Percolation and or evaporation of fuel in the carburetor happens when the engine is shut down.

[55 Fargo]

Very good idea(s), now, wonder who on here is clever enough to make a proto type complete with instructions of a carb heatshield?

I would venture to guess a lot of members would be interested.

Heat soak, underhood temps, cause a lot of issues, call it "vapor lock", most likely in a lot of cases it's fuel boiled out of a carb, and fuel line from fuel pump to carb, and/or percolation.

Modern fuels, especially anything remotely associated with ethanol, is a huge factor, with a lower boiling point of modern gasolines  perhaps.

I would venture to guess the carb base heat shield is doing the most in this situation, the wrapped exhaust is helping too, but on a 95 degree day, the under hood temp, and heatsoak is wickedly high as you have attested.. 

Edited July 6, 2014 by Fargos-Go-Far

[T120]

Good to hear it works for you...Hudson used a similar idea fitted at the base of the carburetor(s) - both single and dual at least from 1940 onwards,listed as a "heat deflector"

[Conroe Powdercoating]

yeah, I was going to make one sandwiched between two gaskets under the carb but real world, the bowl area is the concern and that being said, was pretty easy to make one that easily clamped to the intake runner holding it securely. The carb being over the center of the exhaust means heat saturation is a definite, and yes, the heat wrap helped but the main issue was resolved with the heat deflection, making it take a different path besides directly to the carb bowl.

Heck, I may make one and get a few stamped out with the cleaner version as a go-by.

[DonaldSmith]

My car comes with a heat shield under the carburetor.

 

[Conroe Powdercoating]

^^ looks home made, very cool, thats what I was thinking about making but took the easy route. I do like how they expected enough heat that they felt the need to bead roll for strength and prevent curling, brilliant

[T120]

yeah, I was going to make one sandwiched between two gaskets under the carb but real world, the bowl area is the concern and that being said, was pretty easy to make one that easily clamped to the intake runner holding it securely. The carb being over the center of the exhaust means heat saturation is a definite, and yes, the heat wrap helped but the main issue was resolved with the heat deflection, making it take a different path besides directly to the carb bowl.

Heck, I may make one and get a few stamped out with the cleaner version as a go-by.

You may find this interesting...A Hudson Twin H running on a test bench  - the heat deflectors can be seen at the base of the carburetors..

http://www.youtube.com/watch?v=wA3DCIpiAhs

[Conroe Powdercoating]

I wasnt claiming this as a new invention , I know the heat shield has been around forever,  just my idea to make one that straps to the intake runner and that idea was born from my laziness not to want to remove the carb to accomplish the objective at hand.

Just thought you guys might like some real world data that the hot start issue can be easily resolved with old technology :-)

[Dodgeb4ya]

My car comes with a heat shield under the carburetor.

 

carburetor heat shield.JPG

A factory aluminum MoPar heat shield-I think came out in 1953 or 1954.

[DonaldSmith]

I'm all for cobbling your own solution.  And it doesn't have to be pretty. If it works, it's beautiful.  Good old American ingenuity. Tin snips and hose clamps- I love them. 

[50desotocoupe]

Thank you for posting this!  I think you have a great idea going.  I just bought a fuel pump shield on ebay and would like to cobble something together for my car on my Desoto. 

[Lumpy]

You know, Lumpy has never had that problem...but the carbs sit on an aluminum manifold...I wonder if the aluminum dissipates the heat better/faster, or something like that. It must. No duh you might say!

 

We used to make those heat shields all the time for our big and small block Mopar V8's. They work. You can get real creative and make them in different shaps, like the pentstar (sp?) and such.

 

Hmmm....now I wonder just how long that Hudson motor is.........?

 

k.

Edited July 6, 2014 by Lumpy

[dlrides]

I done the same a month ago, all is good now. I saved the pattern if anyone wants it.

[dlrides]

I done the same a month ago, all is good now. I saved the pattern if anyone wants it.

[Conroe Powdercoating]

^^ more data !

[Conroe Powdercoating]

^^ more positive data added to the pile !

[Dodgeb4ya]

I recently bought this 1954 chrysler 265 engine that runs great, ....

But he must have had a problem with hot starts! ........

Bob

[55 Fargo]

I recently bought this 1954 chrysler 265 engine that runs great, ....

But he must have had a problem with hot starts! ........

Bob

Good score Bob, so Guys, when these cars/trucks/engines, were new 1940s,50s,60s, was this a part of everyday summer heat driving? I have owned plenty of 60s and 70s vehicles in my yoot, but don't recall much issue with summer heat fuel problems.

Is this soul issue of modern gasoline or what?

Edited July 6, 2014 by Fargos-Go-Far

[Conroe Powdercoating]

I recently bought this 1954 chrysler 265 engine that runs great, ....

But he must have had a problem with hot starts! ........

Bob

 

whats up with the twisted belt and pulley issue

Edited July 6, 2014 by Conroe Powdercoating

[Dodgeb4ya]

The car was hit hard in the LR quarter. Not sure why the belt flipped. I put it back and it's fine for now.

The car was a real nice clean original old lady car till a dumb ass pot head rear ended it!!!!!  .

I've got to pull the engine out as thats all I get.

Bob

[Tom Skinner]

Hold the pedal to the floor, then crank it.

Problem solved.

Why make a mountain out of a mole hill?

Oh that's right - that's what the "new" generation does - Groovy man.

[55 Fargo]

Hold the pedal to the floor, then crank it.

Problem solved.

Why make a mountain out of a mole hill?

Oh that's right - that's what the "new" generation does - Groovy man.

While I respect what your saying, and I am sure you have a downright hot summers, and your method works well for your car.

I do know others have no trouble, some minor amounts of trouble, and some a whole heap of trouble.

I don't think some are being modern day whiners, well maybe some, , this problem can be a real pain, when you are sitting at some store or filling station on a hot Juuulllyy day.

Really folks, what were these same engines like way back when, on those hot summer days?????

[Conroe Powdercoating]

Hold the pedal to the floor, then crank it.

Problem solved.

Why make a mountain out of a mole hill?

Oh that's right - that's what the "new" generation does - Groovy man.

 

if only it was that easy, really sucks not being able to restart the car. Easy fix with a heat shield and nope, holding it to the floor didnt work. Nothing to do with being a new generation guy, I am 51 years old. Glad you have no issues with yours in NC old timer. groovy indeed

[Conroe Powdercoating]

While I respect what your saying, and I am sure you have a downright hot summers, and your method works well for your car.

I do know others have no trouble, some minor amounts of trouble, and some a whole heap of trouble.

I don't think some are being modern day whiners, well maybe some, , this problem can be a real pain, when you are sitting at some store or filling station on a hot Juuulllyy day.

Really folks, what were these same engines like way back when, on those hot summer days?????

 

the other day was the killer, I stopped for a subway sandwich to go and when I hopped back in, no start, no way no how. I sat there and ate my sammich and then started it up and drove home, then made the heat shield after that.