Seems to be flooding after shutdown in hot weather

[Sixt8Chrgr]

My 68 440 seems to be flooded after I drive it in hot weather and shut it down and it sits for 10 minutes or longer. To get the car to start I have to floor it while turning the engine over....like it is flooded. Finally it fires with some black smoke coming out of the rear exhaust. I thought maybe the gas was boiling in the carb or maybe the carb is dripping gas in the carb after shutdown? Any ideas?

Thanks

[Chryco Psycho]

install a Fel Pro 1215 intake gasket & block the heat crossover under the carb

[Sixt8Chrgr]

Thanks Physco

[Cooter]

What kind of carb?
Check to make sure float levels are not RIGHT AT the bottom of the sight hole if running a Holley.

Also, look down carb BBLs when shut off and see where fuel is pouring into engine. Sounds like you need some sort of insulator.

[bobs66440]

I think the fuel is percolating in the carb from the heat and spilling over and flooding it.  It seems the Edelbrocks are Prone to that. Mine does it. I tried blocking the crossover. No improvement at all. A buddy with the same problem installed a carb insulator and it fixed it. I'm going to try that next.

[Chryco Psycho]

Pull the top off the eddy carbs & check float levels there as well , they are never right after being shipped .

[Sixt8Chrgr]

My carb is a Holley and I have clearance issues due to running a rpm intake.

[Musicman]

That's to bad, a phenolic spacer under the carb would really help. Blocking the heat crossover wouldn't hurt either.

[Brass]

There are also drop-base air filters out there.  K&N is popular.

[Sixt8Chrgr]

I have a drop base on it now. My car has hood insulation. Would the insulation be adding to the problem?

I also have thought about just replacing the Eddy RPM intake with the stock manifold so I can add the spacer and use the stock breather. I guess that would help.

[Brass]

Or you could find a used Edelbrock CH4B which is what I have.  It sits a little lower than the RPM and I believe it'll perform better than a stock intake will. I also have a half inch spacer and a drop-down air cleaner - no clearance problem.

[Chryco Psycho]

hood insulation can help to trap more heat under the hood , they also seem to collect a lot of dirt & dust right near the air cleaner which is why I do not install them .

[Challenger340]

The Fuel is most definately perculating in the bowls, as all Gasoline perculates above 120*F to some degree...and most carbs exceed 120*F Heat Crossover blocked or not,
however,
it is usually NOT sufficient to "boil" it's way up an Immulsion Tube System(as in a Holley) from the main well....
unless,
the Floats are set too high as already mentioned.

Best diagnostics is to remove the Air Cleaner after shutting off Hot, and look for "steam" in the Carb barrells(fuel vapours).

Phenolic spacers do help, but if height is an issue, try other things first.

Fuel level in the Bowls should be "just" level with the bottom of the Sight plug(removed), WITH the Fuel pump operating or Engine running as the case may be.
Just a 'dribble' should emerge from the plug hole WITH the Engine running, if you "rock" the Car, no higher.

A tear in the power valve system/gasket can also be the culprit, has the Engine ever experienced a backfire up the Carb before ? Do the Exhaust Fumes burn your eyes and stink @ Idle ?

bob out.

[Back N Black]

I have a drop base on it now. My car has hood insulation. Would the insulation be adding to the problem?

I also have thought about just replacing the Eddy RPM intake with the stock manifold so I can add the spacer and use the stock breather. I guess that would help.

I have the Eddy RPM with a stock air cleaner. I used a Ford drop base.

[RECHRGD]

I had the same problem and the heat insulating gasket fixed it (.33" thick, I think).  I also run the RPM intake with a 750 DP Holley and a drop base air cleaner (no hood pad).  It still has about 5/8" of clearance left.    Bob

[firefighter3931]

This link has some good data showing the value of a heat crossover blockoff and base insulating gasket/phenolic spacer.


http://www.dodgecharger.com/forum/index.php/topic,52284.0.html


Ron

[twodko]

That's to bad, a phenolic spacer under the carb would really help. Blocking the heat crossover wouldn't hurt either.

This is exactly right. The fuel is boiling off after shut down. If a phen spacer won't work install The Felpro heat Crossover.

[Sixt8Chrgr]

Thanks guys, several great suggestions. I will go to work and report back what I find out.

Many thanks,

[Sixt8Chrgr]

I checked out the floats and they are ok. I need to get the phenolic spacer and longer studs for the carb, should be ready to go then.....will check out the crossover too.