Best carb for a 440 TNT

[Hansson72]

Hi!
I wonder what you guy's recomend, I have a 1971 crysler 300
TNT that has a edelbrock 800 thunder avs. Everything works fine with the carburator but i think the engine is weak at low rpm. To start a warm engine demands the pedal to the floor until i starts. And i think the mpg is horrible. Still worth i though...
My question is, does a edelbrock 650 thunder avs suits my engine better. Im the cruisimg typ of guy and very seldom goes over 4000 rpm.
I welcome your thougts, thanks

 

[67Monaco]

Sounds like the carb needs to be tuned. If you have to pin the throttle, I'd imagine you have an issue in the idle circuit. Break out a vacuum gauge and have fun.

A good over view of the process;
http://www.centuryperformance.com/forum/showthread.php/42-Engine-Tuning-Using-a-Vacuum-Gauge

 

[commando1]

i think the engine is weak at low rpm. To start a warm engine demands the pedal to the floor until i starts. And i think the mpg is horrible. Still worth i though...

Fix your choke.

 

[70bigblockdodge]

You need some tuning watch is some you tube videos on setting timing and adjusting with a vacuum guages.

 

[Hansson72]

Ok thanks, il give it a try before a try a smaker carb.

 

[thrashingcows]

Or the carb could be oil the fuel out into the intake...thus requiring more air, and a longer cranking time to clean up the excess fuel in the intake passage runners. With all the Ethanol they add to the modern fuel, and with the low boiling point of ethanol, it's troublesome issue.

But a 800CFM carb will owrk fine for you. I would pull the intake and make sure you have an insulation pad under it. Make sure your new valley pan gasket has block off for the heat riser. Also running a phenolic (correct term?) carb spacer...will help reduce the amount of heat going into the carb...and thus boiling the fuel. And a good tune up as well.

 

[Donny]

I just wrapped up my own version of what you're inquiring about, read it over on my thread Donny's 1970 300.