Thread: Edelbrock 1406 floods upon shut down

Tweet

So I replaced my 1704 that was leaking gas after shutdown with a new 600 and found that I still have the same problem. I also had dropped the float level downfrom 7/16 to 1/2" with no luck.
I guess I dont understand that I am running between 160 and 190 temp, how the carb can get hot enough to boil the gas like that. My egr cross overs are blocked off. I am running a 2101 dual plane with headers. I am going to order a 1" phenolic spacer tonight and see if it solves the problem.

1 inch is pretty thick, I think 1/2 inch would do the trick.

Heat wrap on the headders will keep it cooler.

Originally Posted by Bobwall1

So I replaced my 1704 that was leaking gas after shutdown with a new 600 and found that I still have the same problem. I also had dropped the float level downfrom 7/16 to 1/2" with no luck.
I guess I dont understand that I am running between 160 and 190 temp, how the carb can get hot enough to boil the gas like that. My egr cross overs are blocked off. I am running a 2101 dual plane with headers. I am going to order a 1" phenolic spacer tonight and see if it solves the problem.

A couple of thoughts here....
160 is too cold. The motor needs to run at least 190 to help burn off acids and other compounds in the oil that are formed from the combustion of fossil fuels.

NTFDAY is correct about the thickness of the spacer, although If it were my ride, I'd make one from hardwood, using holesaws and drill bits and using the gasket as a template.

I'm guessing that your fuel pressure is exceeding the ability of the needle and seat in the bowl to control the flow of fuel and helping to flood the motor. Edelbrock, Carter AFB and Rochester Quadrajet carburetors will tolerate no more than 5 psi realistically. More pressure than that will overpower the needle and allow the fuel pump to blow raw fuel into the intake manifold. Most fellows tell me that they run best at 4 3/4 pounds with an Edelbrock carb. Carburetors are not like electronic fuel injection, more pressure will not make more power. You need only enough fuel pressure to keep the bowl(s) full of fuel, so use large diameter lines that will support high volume, not high pressure.

Tee off at the carb fuel inlet and run a line back to the firewall, then up past the hood lip to the cowl. Temporarily mount a mechanical fuel pressure gauge, 0-15 psi, liquid-filled on the cowl with tie wraps and duct tape so that you can read the gauge through the windshield. It is only temporary until you can get the pressure under control. Never, ever run a fuel line into the driver's compartment.

.

I had the same problem - flooding after shutdown. Had a small inline fuel filter that was actually touching the motor between the intake manifold and valve cover. As long as it was running, the cool fuel going through it caused no problems. Shut it off, wait five minutes, and the dreaded flooding. Used a 2" rubber grommet to slip over the filter to prevent it from touching the metal it was resting on and my problem was solved. Never did it again..... Hope this may help.

Have a great day,

Milner

Originally Posted by Milner

I had the same problem - flooding after shutdown. Had a small inline fuel filter that was actually touching the motor between the intake manifold and valve cover. As long as it was running, the cool fuel going through it caused no problems. Shut it off, wait five minutes, and the dreaded flooding. Used a 2' rubber grommet to slip over the filter to prevent it from touching the metal it was resting on and my problem was solved. Never did it again..... Hope this may help. Have a great day, Milner

Too easy Milner. Thanks.

.

To techinspector1,

I'm glad to help, that makes my day. Please don't tell anyone that I also bought a new carb after working on the old one, tried carb spacers, etc. and went the same route he did before I finally figured it out. That would spoil my image, lol.

Have a great day,
Milner

I moved my fuel regulator onto the wheel well, and routed the fuel line waaaaay up over the ac box to the fire wall and then to the carb.
I noticed that the header tuber were about 5" from the rt. side frame rail where the steel lines are. so I put heat sheild over that area. It didn't change a thing. The spacer should be here tomorrow, Wednsday. We'll see what happens when I put it on. I think it's the egr passage in the intake causing all the problems. I did put the block offs in when I did the top end in December, but they have small holes in them. Should have fabbed something solid out of sheet metal I guess.
Thanks for the idea's guys!!! It's alway's a pleasure!!!!
Live and learn !!!!