Too lean at idle?

[87mcss]

Okay so I've gotten to where the car will idle and is drivable but now I'm trying to fine tune the idle. Once the engine is warmed up and I'm at base idle it's actually a little on the lean side. If I momentarily choke the carb off or slowly spray in some carb cleaner the idle picks up and smooths out. It'll go from 650-700 to 1000-1050 instantly. So that says to me I need more fuel. This means I need to open up the idle down channel some more, right? Does this sound like right approach? It is already a .064" and the idle tubes are .039".

[Ethan1]

 Sounds right to me. What recipe did you go with? May need to open them up a little more.

[87mcss]

I'm kinda in between 2 and 3. Although, as far as the idle circuits are concerned I guess I'm now fully in the 3rd recipe. In addition to the tubes and restrictions, my idle mixture holes are .104", the bypass air is .109", and the upper and lower air bleeds are .070".

[87mcss]

I ended up opening up the idle tubes (instead of the restrictions) to .045. The idle is excellent now and adding fuel while idling does little to nothing. The mixture screws now have an effect on the idle. Out of gear it is idling around 750-800 and in gear it is around 600.

[Cliff Ruggles]

What is the carburetor part number and what is it being used on?

[87mcss]

Carb #17059508. 400 sbc, 9.4:1 comp, 235/243 @.050, 109°LSA, 103°ICL.

[Cliff Ruggles]

That helps.  Pretty "hefty" cam for the CID and low compression ratio, so it's going to need a LOT of idle fuel and bypass air to be happy.  With 109LSA it's going to a little "stinky" even when you get the carbs idle system dialed in for it......Cliff

[87mcss]

Agreed. You can definitely smell the idle, but I'm okay with that. Right now the idle bypass air is at .109 and it seems reasonably happy with the idle tubes at .045. Part throttle and full throttle haven't given me any issues yet.