Carb tuning - what am I missing?

[440beep]

I've got a Six Pack on a 440+ ci motor. Cam's a roller, here's the specs: duration 240/248; valve lift @50 540/545; LS 112.

Been messing with the carbs (center carb) trying to get the car to idle better. Smelled kinda rich while idling. Fully reset the idle mixture screws and now getting roughly 11-12 of idle vacuum, which is the highest. Idle mixture screws are working, because vacuum dropped to 9/10 with them fully turned in. Cleaned out the idle bleeds with carb cleaner and compressed air. I've got the car idling at roughly 1100 rpms in park, and in gear it drops down to roughly 700-800rpm. Car runs best with this set up.

I've tried getting the idle rpms down to 800-900 (like the factory settings), but when its in gear the car starts floundering really bad with the rpms at 400/500.

Here's something I noticed too. With the air cleaner off, the car runs better at the lower rpm settings. With the air cleaner on, car goes back to floundering. The air cleaner is a 3" K&N filter for the Six Pack. Been awhile since I've cleaned it, so maybe the air cleaner is the issue here.

Other than maybe a dirty air cleaner, am I missing something else to check to help with the idle?

Or do you get to a point with certain cam specs and cubic inches that you need to have the increased rpms and have the carb off the idle system in order to make it run right? Seems odd to me.

 

[Hemi Rebel]

Might wanna check this out. May help. I know they can be fickle when you deviate from stock.

http://www.amazon.com/gp/aw/d/1557885281?pc_redir=1405204511&robot_redir=1

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Where is your timing set. Getting as much base timing in it you can will help with the idle

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And clean your air filter

 

[440+6]

What is your timing set at, should be 18 or more initial with that cam, limit the total to 38 deg

 

[super-bee_ski]

Your 440 has enough "cubes" to handle the cam.

BUT: it almost sounds like your lacking "air"
You remove air cleaner and it "idles" better.
Could you have a vacum leak?

 

[62MAX]

I've got a Six Pack on a 440+ ci motor. Cam's a roller, here's the specs: duration 240/248; valve lift @50 540/545; LS 112.

Been messing with the carbs (center carb) trying to get the car to idle better. Smelled kinda rich while idling. Fully reset the idle mixture screws and now getting roughly 11-12 of idle vacuum, which is the highest. Idle mixture screws are working, because vacuum dropped to 9/10 with them fully turned in. Cleaned out the idle bleeds with carb cleaner and compressed air. I've got the car idling at roughly 1100 rpms in park, and in gear it drops down to roughly 700-800rpm. Car runs best with this set up.

I've tried getting the idle rpms down to 800-900 (like the factory settings), but when its in gear the car starts floundering really bad with the rpms at 400/500.

Here's something I noticed too. With the air cleaner off, the car runs better at the lower rpm settings. With the air cleaner on, car goes back to floundering. The air cleaner is a 3" K&N filter for the Six Pack. Been awhile since I've cleaned it, so maybe the air cleaner is the issue here.

Other than maybe a dirty air cleaner, am I missing something else to check to help with the idle?

Or do you get to a point with certain cam specs and cubic inches that you need to have the increased rpms and have the carb off the idle system in order to make it run right? Seems odd to me.

This also applies to 440-6,you need to do the end carbs !

 

[rumblefish360]

The K&N filters are slightly more restrictive than a paper element when brand spankin new but they will stay at a high flowing level even when they get a little dirty. Clean the filter well and let it dry in a cool dark place so the cotton doesn't shrink up.

The six pack set up also uses the rear carbs at idle. Both of them. As above, the lead plugs need to come out to adjust the rear carb. This is a huge pain in the *** for most people. And I don't blame them for hating. Not one bit.

I have found that hand book of little help.

Between the large street cam you have in there, timing and carb setting is everything and a little tricky. The above advice was good. As much initial as possible with a limit on total. (Without the vacuum hooked up)
Start there. Go back to the carbs.

(Limit total timing to 52*'s with the vacuum advanced hooked up.)

What stall converter are you running by the way? The drop in RPM's in Gear seems to be a lot. Is the converter is loose enough?

 

[440beep]

I've got my inital timing at 10 degrees, and think total is at 34. Tried running the initial timing at 15 degrees one time, but idling in traffic was an angry bear. Went back to 10 degrees and she's a queen idling in traffic.

Stall converter is 2200rpm. Didn't want a high one since i've got a 4:10 gear which gets the motor in its rpm range quick.

I will have to double check my total timing again and see where its at. And clean the air filter.

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Oh, and I've got that Six Pack book. Have almost worn it out using it so much.

 

[furyus]

I've got my inital timing at 10 degrees, and think total is at 34. Tried running the initial timing at 15 degrees one time, but idling in traffic was an angry bear. Went back to 10 degrees and she's a queen idling in traffic.

Stall converter is 2200rpm. Didn't want a high one since i've got a 4:10 gear which gets the motor in its rpm range quick.

I will have to double check my total timing again and see where its at. And clean the air filter.

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Oh, and I've got that Six Pack book. Have almost worn it out using it so much.

you need to reset the carbs after you increase timing.

 

[440beep]

Yes, of course. Know that.

you need to reset the carbs after you increase timing.