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What RPM should a mild 440 sixpack idle at?

Started by GrandpaKevin, July 22, 2018, 01:42:42 PM

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GrandpaKevin

Is 750 RPM idling in gear about right for a mild 440 sixpack engine?

I did some fine tuning on the wife's Challenger today.

The 440 is a fresh build with 10-1 forged pistons, Stealth aluminum heads and a mild Lunati Voodoo camshaft https://www.summitracing.com/int/parts/lun-10230702lk

The main issue was the car would stall during braking and had a rough shakey idle when sitting in gear.

In looking at a couple spark plugs and the light colored soot on the exhaust tips the car appeared to be running lean.

I first checked the float levels in all 3 carbs and lowered them a bit.
I then re-adjusted the mixture screws on the center carb.
I next covered the air bleeds on the outboard carbs and the idle increased quite a bit, especially on the rear carb.
From what I understand that means the carb is running lean.
Thankfully I installed fuel mixture screws in the rear carb from Six Pack solutions when I went through the carbs.
I also made sure the idle adjustment screw on the center carb wasn't open too far as to expose the transfer slot too much.
It was a little tricky but I was able to adjust the mixture screws on the rear carb without removing it. :)
This made a huge improvement in the way the car ran and idled.

I adjusted the front outboard carb and got them both to where the idle slightly dropped 20-30 RPM when the air bleeds were covered.

I have the timing set at 18 initial and 36 total.

So now the idle is smooth and rock solid at 750 rpm in gear and the engine RPM's hold steady even during hard braking.
I'm hoping to call today's project a success.







1 Wild R/T

Sounds pretty successful to me but before giving it approval we need a full road test including tipping all six to redline.....  :pokeeye: Training manual states it's a requirement ya understand.......

GrandpaKevin

Quote from: 1 Wild R/T on July 22, 2018, 01:47:22 PM
Sounds pretty successful to me but before giving it approval we need a full road test including tipping all six to redline.....  :pokeeye: Training manual states it's a requirement ya understand.......

No worries, during the road test all 3 carbs opened perfectly and after a quick blast down the highway it was determined the idle is rock solid during hard braking. :burnout:


1 Wild R/T

Well then.. Crack a cold one & put your feet up.... :cheers:  Or do as I do, mix up a few margaritas & enjoy....

RUNCHARGER

Yep: That sounds good to me. I idle them a bit higher than I used to with all the lifter problems lately.
Sheldon

734406PK

#5
I set my idle at 950 rpm in Drive (727)  with A/C. I have the idle up solenoid but don't think it's really necessary.  Currently running a Mopar .484 Purple camshaft, not the best by today's spec but soon to change ...

screamindriver

Great looking engine bay... :bigthumb:  Sounds like it runs as well as it looks...


Morty426


fc7cuda

If 750 is what the motor is telling you, then I'd leave it there.  :alan2cents:

Cratos

Anyone know where to get a new solenoid ? hoping to get the body back this month,  motor ready to go except for the darn solenoid.