Vapor lock 70 Cuda 383 Shaker

[Racer57]

I have a 70 Cuda with a 383. It has a shaker and a 600 Eldebrock carb. I'm using the factory style steel fuel line that clears everything without touching, but does get almost too hot to touch. The engine temp is 185-190 and heats up to 200-210+ when sitting shutoff like at a gas station and of course cools right down after getting it started.

Any ideas on what can be done ?

 

[moparleo]

Are you running the fuel line in the engine compartment in the stock location? Headers ?

 

[Racer57]

Are you running the fuel line in the engine compartment in the stock location?

Yes.

Headers ?

No.

Car was frame off restored. Everything is new/rebuilt and in stock locations.
Thanks for replying.

 

[moparleo]

OK, does the engine shutoff by itself when you come to a stop or are you just saying that the line gets hot when you shut off the engine ?

 

[Racer57]

The line gets hot after shutting it off.

Car runs ok at all times. But after shutting it off after engine has gotten hot, especially on 85-90 degree days, I have to crank it for a lot longer than normal to start and at times it will start then die and restart the same was when you've ran out of gas and its still pumping new into the carb. The steel fuel line gets almost to hot to touch even though it touches nothing and is the same height as the top of the distributor which it goes across the top of which is why I'm sure that I'm getting vapor lock.

I also did take the flaps out of the shaker to allow more air movement since I never drive the car when its raining or during the winter.

 

[moparleo]

You can do 2 things. Install an electric fuel pump back by the gas tank and get some fuel line insulation for the under hood fuel lines.

 

[Racer57]

Thanks.

 

[moper]

What initial timing are you running? What was done to tune the carburetor?

 

[Racer57]

14 initial 35 total +/- 1 without vacuum hooked up. Other than idle air speed being adjusted slightly, I strongly feel that its set ok. It works perfect at all times.

I am starting to wonder if I shouldn't try changing the fuel pump. I "might" have the small block version instead of the high performance one for big blocks.

 

[Chryco Psycho]

using a 1214 Fel Pro intake valley pan will block the heat crossover limiting heat to the intake & carb , installing the 3/8 fuel line & sender will get you a return line back to the tank circulating more fuel to keep it cooler , using a pipe insulation on the line will help as well .

 

[Racer57]

using a 1214 Fel Pro intake valley pan will block the heat crossover limiting heat to the intake & carb

On order. Thanks !!!

installing the 3/8 fuel line & sender will get you a return line back to the tank circulating more fuel to keep it cooler

I only have one line. If I have understood correctly, the 71 and later models had a return line. Is that what your saying I need to get ?

using a pipe insulation on the line will help as well .

Already have it.

Thanks !

 

[moper]

Was the engine rebuilt? Stock or modified camshaft?

 

[Racer57]

Was the engine rebuilt? Stock or modified camshaft?

Fresh rebuild. Stock cam.

 

[moper]

As a stock rebuild it should not need the blocked off intake crossover, any return, or any insulation. Infact as a restored car I'd lean away from the return line or insulation because it will be very visible and very incorrect. What I would suggest is you have it tuned a little further. If the timing is set to factory specs and the float level in the carb has not been at least verified - that might be why. It sounds like the timing is retarded, not vapor locked.

 

[Racer57]

It sounds like the timing is retarded, not vapor locked.

When the car has gotten enough heat built up after being shutoff and after enough cranking, it will at times try to fire before it finally does. Very similar to when an engine has ran out of fuel and you pour some down the carb. It only happens when the water temp has gotten up to 190, but starts immediately when warm.

Thanks very much for your input, it is appreciated.

Btw, even though I want to keep the car as correct as possible, items like that do not bother me any at all considering this is a car that I've wanted for 40 years and have no intent on ever selling it. When I take it to car shows, I do not officially enter it because I refuse to take the credit of someone elses hard work.

 

[clonewars]

vapor lock

I can only speak with my times as a stock car racer vapor lock is 90% caused by heat which you can cure with as easy using aluminum foil the other 10 % is the line location in reference to the fuel pump. Or just a bigger fuel pump

 

[Chryco Psycho]

I refuse to build virtually any engine without blocking the heat crossover , most of these cars are never run in cold weather anymore & it just adds far too much heat in the intake which is entirely unnessisary , Electric chokes are far more efficient than heat stove types

 

[moparleo]

An electric pusher type pump doesn't care how hot it is.

 

[Chryco Psycho]

true but the fuel still gets hot & can boil once the fuel enters the bowl & the pressure is lost ,at least a return line will keep it circulating

 

[moparleo]

True, true, cold fuel/air is always better.