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Rich idle is killing me

I can't tun **** with the vacuum gauge as far as fuel mixture screws go. That just keeps increasing as I screw em in and the car runs like **** lean. So I left them where they are and it seems to be happy there for now. Now I know why some of you guys that have been at this for 40 years say to hell with it and go buy a hellcat!
:thumbsup::thumbsup:
 
I can't tun **** with the vacuum gauge as far as fuel mixture screws go. That just keeps increasing as I screw em in and the car runs like **** lean. So I left them where they are and it seems to be happy there for now. Now I know why some of you guys that have been at this for 40 years say to hell with it and go buy a hellcat!
:thumbsup::thumbsup:


I can order a lot of stroker kits from 440 source for what the cost of that hellcat is

 
Yea at a higher idle its way better. If I dump it back down to 750-800 RPM I can actually watch it start to load up and smoke a bit after 20 seconds or so of idling there. Then I bump it back up to 900ish RPM and it'll clean up once you crack the throttle a few times and clean it out. I have to remove the carb AGAIN and open up my holes in my throttle plates a bit to get some more air in. Right now, I am using my secondary throttle plates too much I feel and have too much transfer slot open and exposed. I wanna get that closed up a bit and maintain my 900RPM idle. I figure I will go up 2 drill sizes on them and see how that likes it. If I go too much, I have a spare set of throttle blades I can use to undo that. That new Holley XP carb they offer with the air bleed inside the center hole for the air cleaner stud is an awesome way to combat this problem of on again/off again for the carb drilling/adjustment. :D
 
Nothing wrong with a 900 rpm idle. Do you have a wideband o2 sensor? I'm not sure drilling throttle blades is the right thing to do in this case.
 
Nothing wrong with a 900 rpm idle. Do you have a wideband o2 sensor? I'm not sure drilling throttle blades is the right thing to do in this case.

They are already drilled. All four plates have been drilled since I first started tuning the engine this spring. ZERO chance this engine idles without them drilled even at 28 intial at idle and 34 total. Tried that before I drilled my new plates I installed and it needed to be so far open it was hopeless. I do not have a wideband O2 but I am going to drive the car a bit the way it is anyway and see how it acts. If it drives nice and doesn't burn my eyes, I may leave it the way it is for now.
 
So I installed the .033 IFR and put 72 IAB in it tonight. I have since realized that this motor will not idle below 850-950 RPM without running pig rich. I raised the idle using the secondary screw and ran it up to 950-1000 in which it cleared the idle up considerably. I fear with the big cam, and 8.5-9 in/mg. of vacuum, there is no way it'll clean up at the low idle. It seems to run alot better idling at 900 or 950 then at 800 all day long. The idle screws are a smidge under 1 turn out on all four corners. I think I have got it atleast do able for now with how it is at the moment. I am going to a car show Wednesday, so I will take it for a ride after all my idling and tuning and clean the plugs off good for a good blast. I will then judge where I am at after a little cruise.
i told ya to raise the secondary clean this up.
 
I can't tun **** with the vacuum gauge as far as fuel mixture screws go.
Mine is a totally different animal, mild-ish cam, crossram w/600cfm Eddys. Your big cam is a big game player, getting it dialed in.
I had problems with mine too rich, loads of carbon, and trying to adjust mixture via RPMs, was not getting any results. Had been checking manifold sealing, with a vacuum gauge, getting 16". Decided to play with the screws a little, going by vacuum, leaning it, vacuum up to 18". No more carbon, cleaned up real good.
Though, on mine, jetting is about right, in range. Don't know on your's, including the cam. Makes for a good fight! Good luck on it.
 
i told ya to raise the secondary clean this up.

It is raised now. Conflicting info. One says raise the secondary and other says no transfer on the secondary......Right now I am messing with some small stuff but it is pretty close. Essentially by opening the secondaries that far, you are taking the engine into the transition circuit and off the idle circuit. I can add air via drilled plates, and stay on the idle circuit of the carb. Now I have seen multiple different info on this as well. Some say the secondaries are not doing anything until they are open and others say it is drawing fuel in the transfer slots on the secondary no matter what the throttle position is or whether the secondaries are active or not.

:thumbsup:
 
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Mine is a totally different animal, mild-ish cam, crossram w/600cfm Eddys. Your big cam is a big game player, getting it dialed in.
I had problems with mine too rich, loads of carbon, and trying to adjust mixture via RPMs, was not getting any results. Had been checking manifold sealing, with a vacuum gauge, getting 16". Decided to play with the screws a little, going by vacuum, leaning it, vacuum up to 18". No more carbon, cleaned up real good.
Though, on mine, jetting is about right, in range. Don't know on your's, including the cam. Makes for a good fight! Good luck on it.

Yup my powerwagon 360 and my Runner are both close to stock. Both can be tuned with a vacuum gauge for the idle. This thing HATES the idle setting where vacuum is greatest. Acts lean and surges. It wants fuel. I am just finding the happy medium between fuel needed and fuel not needed to burn the eyes a bit less. At this point the way it sits, it is off the idle circuit using the secondaries to adjust the idle this high, so it needs to be drilled a bit bigger and then transfer slots closed up so its back on the idle circuit.
 
yes opening them up just a tad could pull fuel,you just have to turn down the idle,that it wont pull fuel,giving more air.my last 360 69 dart had the 280-474 purple cam that ran rich big time,opening the secondaries up just past the slot sure help.glad your getting there.good luck.

sony pic 203.jpg
 
Sounds like you’re on track, they usually take some playing with. If you maxed out on initial and the butterfly’s are still too far open you can always add a touch more bypass air.

Think I should supplement the air from the blades being open with a little larger holes in my plates to keep fuel from dragging in on the transition circuit, or leave it as is with the secondary blades open a decent amount? I noticed my power brakes and vacuum canister being a bit worse so I think if I can get the blades closed and the holes bigger, I can help that as well.
 
Thank for starting thread. Have battled same thing with about the same cam specs. With 2-3116's on a crossram. Ifr hole is .060 dia, put a set screw drilled to .030 to lean carb out with some success but could be better. Pic putting drilled set screw in tapped hole.
c1.jpg
 
Gotta move them IFR’s low
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Think I should supplement the air from the blades being open with a little larger holes in my plates to keep fuel from dragging in on the transition circuit, or leave it as is with the secondary blades open a decent amount? I noticed my power brakes and vacuum canister being a bit worse so I think if I can get the blades closed and the holes bigger, I can help that as well.

They’re decently sized. Try 1# drill larger at a time.

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E71399B3-2D6E-474A-B711-D078D27C2F29.jpeg
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Holley Sniper EFI is looking better and better by the minute.....HAHA
 
Gotta move them IFR’s low
View attachment 785442 View attachment 785443



They’re decently sized. Try 1# drill larger at a time.

View attachment 785444 View attachment 785445 View attachment 785446
If you talking about my post, your advice to keep IFR's low? Been follow your work on carbs since a thread or a post "Idles like a six cylinder". Wondering how those carbs are setup. Been watching hoping to pick up tips. Didn't want to hijack thread but your box is full.
 
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If you talking about my post, your advice to keep IFR's low? Been follow your work on carbs since a thread or a post "Idles like a six cylinder". Wondering how those carbs are setup. Been watching hoping to pick up tips. Didn't want to hijack thread but your box is full.

Should come through now
 
Please tell us all of your cam specs. Advertised duration and 0.050" duration for both intake and exhaust, LSA, ICL, hydraulic or solid. If its a solid, what the lash setting is. Then tell us what you've done to confirm that there is no vacuum leak. A lean miss at idle due to a vacuum leak can be subtle, and will always cause your eyes to burn, and almost always perceived as "it's too fat at idle".

Honestly, for me, it's a little hard to believe you're even on the right track. I put bigger cams in smaller motors back in the 1970s, 80s and 90s, way before there was an adjustable anything on a carb, and they would run better out of the box than what you're describing.
 
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