557 in Zephyr. Got the carb percolatin' blues (HELP!) (link)

The Zephyr's got a 557. And a problem...

Here's the whole percolating gory story. Help if you can!

http://www.firstcoastcobraclub.com/viewtopic.php?f=8&t=743

Thanks,

Tom

Link wouldn't work for me.

BigDave65,

I'm pretty sure I fixed the link!

Thanks for the heads up.

Tom

would you have something heating your fuel before it even gets to the engine? header too close to the line?

Where does the fuel line run in the engine bay? Where is the regulator?

Sorry for brief reply - I'm headed out to the Daytona Flea Market.

Reg is on firewall near pass side fender. Fuel line goes straight toward the firewall then turns toward the reg. Fuel line passes behind pass side head but nowhere near exhaust.

I insulated the line from the carb to the reg. No help.

I think maybe I have to somehow get some air circulating under the hood - it's pretty tight under there.

Maybe use a very small air filter - one of those little dome-shaped this that sell for about $20 - until I figure out something else.

Hood louvers? Fender vents?

Bottom of drop base air filter too hot to touch after 30 minute run...

Thanks for any suggestions.

Tom

I fought the same issues last year with a build. I put all the same stuff on you did. What I did to find the problem was went to a hardware store and bought some of that black rubberish looking stuff to insulate lines with on you a/c unit in your house. Put that over my 3/8 fuel line and let it idle until it quite on me. Then let it cool and you could see where the stuff I wraped the line in had melted. That part of my fuel line was at least 6" away from the exhaust, but it was still heating the gas up enough to boil it. After rerouting fuel lines it ran fine.

Tiger,

I just insulated the fuel line. It's a foot away from the exhaust. It didn't help

I'm now going to try running the car with no hood. I think it's the buildup of underhood heat (try saying that fast three times) that gets to the fuel bowls.

I think if I can get enough airflow in the engine compartment to carry off the heat, the problem might go away.

For example, I can run all day on the highway and everything is OK. If I stop, the fuel boils. I seems like the underhood temp goes way up when I don't have enough air flow.

If the "no hood" approach works, I'll try to ventilate the engine compartment by opening up the fake air scoop, the fake fender louvers and maybe putting a bunch of louvers or some expanded metal in the top rear section of the hood.

Not sure I could have more fun than this. Ugh.

Tom

If you have an electric fan, put it on a temp switch and it will run a few minutes after you shut the engine off cooling the underhood temps a bit. I think it would work anyway!

when i had a 460 in my 69 mustang it had that problem in hot weather.i could'nt find a valley pan intake gasket for cj heads but i always thought it'd help by keeping the hot oil off the alum intake.

March 26 update at the bottom of the thread here: http://www.firstcoastcobraclub.com/viewtopic.php?f=8&t=743&p=3799#p3799

Maybe the fuel line is picking up some heat somewhere...

Tom