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Discussion Starter #1 (Edited)
Hey everyone,
I am new to this site and I am the proud owner of a 1971 Nova and I need a carb. It originally had a straight six and a powerglide. I ripped that juck out and put a 350 with Dart pro one heads (2.02/1.60 200cc intake runners), .488/.510 cam, and 1.6 roller rockers that bumped the lift up to .520/.544. I also installed a rpm air gap, running msd 6al (HEI) with super cunductors, hedders and all the other essentialls. My compression is around 10:1. I need a good carb I am pretty sure I want to run a 650cfm but I am not sure what brand. I have a holley 650 double pumper that I rebuilt. I installed the correct power valve for my application also and it still runs so rich. It makes my eyes water when it is in my garage. I had an edelbrock performer 600 on before and it ran like a champ. Any advice?? I am in Iraq right now and I am trying to get everything set up before I get back so I can spend a couple days installing everything. Sorry about the info but I just want to give you guys as much info as possible. I want to make my car more of a touring/ strip car I drive it everyday and I could care less how expensive gas is I love my car and lifes to short to care. I keep exxon in business!!!
Thanks,
Guy :chev:
U.S. Navy
 

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Based on your description, it sounds like your current carb could use some more tuning before deciding it's not living up to its potential.

If it's making your eyes water while idling in the garage, your idle mixture screws are probably adjusted waaaaayyy rich. You're going to need a vacuum gauge to tune that setting properly.

No carb is going to be perfect just bolted on out of the box, especially a Holley. The other guys here can probably offer you more detailed info regarding what the appropriate CFM for your engine is, but tuning is going to bite you in the butt if you ignore it on ANY carb.
 

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Discussion Starter #3
I tried messing with the mixture screws I have them set at 2 turns out. I think I am going to take your advise and keep the carb. It only has 2 corner idle screws. I think I am going to buy the four corner set from quick fuel. Is there anything else you guys recommend I try?? What about my fuel float setting?? and my accelerator pumps?? Would that make a diffrence. I want to be able to just turn the key and starts right up on the first crank. Any tips and/or trade secrets to know about
Thanks
 

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Discussion Starter #5
I belive my initial timing is around 18. Can't quite remember what my total is I will check once I get back home. Still in the middle east
 

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Discussion Starter #7
Thanks for your support. That makes it all worth it!!
 

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I had a recent problem with my carb running really rich at idle. I could adjust the idle mixture screws all day long and see no changes. After discussing it with the guys here and playing with it, it turned out that my idle speed was set to high which uncovered the transfer slots too much and let the carb dump fuel into the intake at idle.

Turning the idle speed down (yes, down) to partly cover the transfer slots again and then adjusting the mixture screws to get max manifold vacuum at idle brought the idle speed back up and cured my rich idle condition.

Simply turning the screws X turns isn't taking anything into account regarding what your motor really wants for fuel at idle. There's no hard and fast standard for every motor, but the highest vacuum reading is what we're after.

A Holley tuning book is a good investment. Mine has already paid off, along with a couple years of attendance here. :)
 
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