holley 4180 screw in idle jets.

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Ristow
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Joined: Fri Mar 29, 2013 8:46 am
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holley 4180 screw in idle jets.

Post by Ristow » Tue Apr 16, 2013 1:40 pm

seeing if screw in idle jets are viable for the 4180. it looks ok on the junk metering block i have. will allow easy,changeable in both directions idle jetting on the 4180 Holley. idle jetting plays a bigger role in cruise behavior than most realize. at cruise you are pulling as hard as the engine can on the idle jets,and just coming onto the mains. lean idle jets tend to force the driver to lean into the throttle more than would be otherwise necessary,to bypass the lean condition the idle circuit is giving,and get more onto the mains,which will probably be fatter than needed to compensate for the lean idle.

the 4180 is a bit different than the standard 4150/60 holley. the idle jets are directly behind the main jets,rather than the backside of the metering block.

a press in jet is used stock. shown here.

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it is pulled out,hole is drilled and tapped to 8/32.

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the same jets i am using for the air bleeds is used here. brass 8/32 set screws.

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installed,it almost looks factory.

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with the adjustable air jets,and idle jets,the mixture,and the transition is able to be dialed in,which really needs to be dialed in on most carbs. i wouldn't buy a new carb that did not have screw in air bleeds,jets and pvrc's
It's like you're unraveling a big cable-knit sweater that someone keeps knitting...and knitting...and knitting...and knitting...


jamesdart
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Joined: Tue Dec 25, 2012 4:49 pm

Re: holley 4180 screw in idle jets.

Post by jamesdart » Tue Apr 16, 2013 2:59 pm

looks interesting. i have a real clean 4180 id like to setup for the wagoneer.


AwesomeJ10
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Re: holley 4180 screw in idle jets.

Post by AwesomeJ10 » Tue Apr 16, 2013 4:14 pm

Meet Mr. Ristow - the Carb Whisperer.


Topic author
Ristow
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Joined: Fri Mar 29, 2013 8:46 am
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Re: holley 4180 screw in idle jets.

Post by Ristow » Tue Apr 30, 2013 12:38 pm

fully adjustable 4180 metering block.

idle jets. 8/32 threads.

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and PVRC's. 6/32 threads.

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with my adjustable air bleed main body,i now can dial in fuel on the idle,main and enrichment circuits,and tailor the transition of the idle and main circuits as well. fully adjustable. in both directions.
It's like you're unraveling a big cable-knit sweater that someone keeps knitting...and knitting...and knitting...and knitting...

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Addicted
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Re: holley 4180 screw in idle jets.

Post by Addicted » Tue Apr 30, 2013 1:48 pm

Interesting.

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