Correct Idle speed

[mountain33]

First I apologize if this has been answered before. I have just spent last half hour looking on site for information regarding the idle speed. I have a 71RR with 383 automatic, Holly 4barrel. Everything is stock like it came out of the factory. I want to set the idle but have no Idea what the correct Idle should be. Manual i have told me to look at sticker under hood. No sticker. Ive looked all over manual all I could find was a mention about setting up solenoid idle to 900 rpm if i had a manual trans. I connected tach and its about 900.

 

[BLK 68 R/T]

You can set the idle pretty much anywhere you want. I’d shoot for around 800rpm and see if you like it and adjust from there. The lower the rpm you can get it to idle the better it will sound. I wouldn’t go below 650 rpm though.

 

[33 IMP]

Set it where YOU want it, some 50 year old number means dick. I like 750rpm for a stock street car, but my bracket race cars idle around 1200. 900 is a little fast for a stone stock car, but if it helps you to drive the stick easier, fine!
The "correct idle speed" is the one you are happy with.
Edit: for some reason i thought the op had a 4sp. My oops. Still stand by my opinion.

 

[dadsbee]

My 340 Dart won't idle below 900 in Drive, the 4 gear Bee I can turn down to 600 IF I want but have it set at 800.

 

[toolmanmike]

Set it where it and you are happy. Stock spec is probably 650 in drive.

 

[Ron H]

As posted setting idle speed to where you prefer can be done and is influenced by how the carb is set using an rpm and/or vac baseline. Timing/setting impacts the idle speed as you may know. There are ‘parameters’ where the engine takes a smooth idle and then checking its change when putting it in gear. Not aware of the stock spec’s; but 900 sounds high like somewhere around 200 rpm or so, IMO. When you put it in gear at a higher rpm setting the car will lurch and want to have a fast foot on the brake to stop it from moving. Not sure what the specs are for your ride. For mine, the setting is around 650 and when dropping it in gear it drops to around 500.

 

[mountain33]

Thank you all for taking the time to reply. Will lower to 750 and adjust carb accordingly. I had rebuilt the carb last year. Setup idle by ear and had adjusted the 2 idle mixture screws by vacuum reading. Just bought an old craftsman dwell, tach, damn getting old forget what else it does meter plus timing light from retired vw mechanic. Thanks again

 

[Crackedback]

Get a good idle timing profile and advance curve on it. That will make the ability get the idle down a lot easier. If it's timed by the book, it's not close to optimal.

 

[MoparLeo]

Factory specifications for a stock engine.
http://www.tpocr.com/plymouth2.html

 

[440 Charger]

First I apologize if this has been answered before. I have just spent last half hour looking on site for information regarding the idle speed. I have a 71RR with 383 automatic, Holly 4barrel. Everything is stock like it came out of the factory. I want to set the idle but have no Idea what the correct Idle should be. Manual i have told me to look at sticker under hood. No sticker. Ive looked all over manual all I could find was a mention about setting up solenoid idle to 900 rpm if i had a manual trans. I connected tach and its about 900.

Does it stall at idel?

 

[MoparLeo]

Did you click the link on post #9 ?

 

[MelroseMopar]

If your turning idle down really low(below 675 IMO) be sure to keep an eye on oil presser as some engines need a little bit of RPM to maintain decent oil presser

 

[oldkimmer]

If your turning idle down really low(below 675 IMO) be sure to keep an eye on oil presser as some engines need a little bit of RPM to maintain decent oil presser

And to lube the cam. To slow if an idle is the easiest way to eat a cam. Kim

 

[Ironbuilt]

Both of my big blocks like 900 RPM in park. The chart @MoparLeo says 800 with an AT, but my high compression and large cam 440's want to stall at 800.

 

[MoparLeo]

Key words are "high compression " and "large cam".
OP said it was a stock build 440.
http://www.mopar1.us/engine2.html

 

[Jonas Nordstrom]

As many have said, set it where you and your engine likes it.

Mine is stock and runs really smooth at 800rpm in park, drops to 650 in drive and is rock steady.

 

[AR67GTX]

My GTX has AC and no relays on the headlights so I used to set it’s idle speed in gear at whatever it takes to generate reasonable headlight brightness at night with the AC engaged. In recent years I’ve sort of compromised by installing a looser converter, installing an idle solenoid hooked up to the AC compressor, and re-tuning the distributor to allow running 14 deg initial base timing. Engine idle hardly even changes anymore when I put it in gear.