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    Results 1 to 12 of 12
    1. #1
      Join Date
      Oct 2009
      Location
      CT.
      Posts
      738

      Need advice on carb selection....

      I recently acquired a 66 Chevelle that has a 454 in it. It has a very stout cam, has Rectangular port 69 Corvette heads, and open plenum Weiand intake and a AED 850 carb on it now. This is a 4 speed car if that matters much. I just did a rear gear swap to make the car more drivable to my liking. The guy liked stop light to stop light cruising and had 4:88's in it!

      So with 3:55's the car is definitely more drivable. With the cam that is in it I need to pull away from a light or stop sign with the RPM's up higher then I like. I have been told by many to swap out the intake and carb to a duel plane intake like and Edelbrock RPM or something like that. So that is next, but what about the carb? What do I really need?

      Planning to most likely get a Holley, but which one? Is a 750 the only way to go hear? Is the Street Avenger 670 too small?

      Remember, this is a street car. I will never take it to any type of track, drag or autocross. Cruise nights, local car shows, out with friends etc.



      Appreciate any advice you guys can offer.

      Thanks,
      Glenn



      Glenn

      1955 Chevy BelAir
      1951 Chevy 3100
      1987 Chevy Silverado

      My last project....
      https://www.pro-touring.com/threads/...my-72-Maverick!!

    2. #2
      Join Date
      Sep 2010
      Location
      Orange County, CA
      Posts
      665
      Swapping the intake and carb may help increase bottom end torque, but with a big block you will already have plenty. It sounds to me like maybe you have too much cam for the street. Do you know the cam specs?

    3. #3
      Join Date
      Sep 2011
      Location
      So Cal
      Posts
      254
      http://www.gtsparkplugs.com/CarbCFMCalc.html
      Not the end all solution for picking a Carb but maybe a guide to get you in the ballpark..

    4. #4
      Join Date
      Dec 2010
      Location
      Fredericksburg, VA.
      Posts
      3,155
      Country Flag: United States
      Personally, I would not spend any money on a carb. Take a look at FITech they offer a reasonably priced throttle body EFI which will outperform a carb.

      http://fitechefi.com/
      Steve Hayes
      "Dust Off"
      68 Camaro

      Given sufficient initial acceleration, even pigs can fly!

    5. #5
      Join Date
      Mar 2008
      Location
      Chicago suburbs
      Posts
      667
      Country Flag: United States
      I had a great experience with Pro Systems when I bought my carb from them in 2007ish. Best carb I ever had, no doubt. You give them all of your vehicle info and they "build" a carb to match. That being said, this year I swapped to efi and will never go back.

    6. #6
      Join Date
      Oct 2009
      Location
      CT.
      Posts
      738
      I am going to install EFI on my project car, but on this one I just want to replace the carb and call it a day. I plan on selling this next year and really don't want to invest the money to put injection on it.



      Glenn

      1955 Chevy BelAir
      1951 Chevy 3100
      1987 Chevy Silverado

      My last project....
      https://www.pro-touring.com/threads/...my-72-Maverick!!

    7. #7
      Join Date
      Mar 2008
      Location
      Chicago suburbs
      Posts
      667
      Country Flag: United States
      Nothing wrong with going with a carb, but are you sure that you have a carb issue? Do you know your cam specs and your compression ratio? If those are mismatched you may never make good low end torque. Same goes for a motor with a big cam built for high RPM- generally low RPM power suffers. You may just need a new intake and flat tappet cam, which would be cheaper than a high end carb. More info on the motor would help...

    8. #8
      Join Date
      Apr 2014
      Posts
      15
      Country Flag: United States
      Tune the current setup. Plugs, timing and idle circuits. Measure your vacuum at idle, 850-900 rpms. below 10" and your cam most likely doesn't like the new gears. Im betting its not tuned for normal cruising and the cam is too big

    9. #9
      Join Date
      Oct 2009
      Location
      CT.
      Posts
      738
      Quote Originally Posted by another69 View Post
      Nothing wrong with going with a carb, but are you sure that you have a carb issue? Do you know your cam specs and your compression ratio? If those are mismatched you may never make good low end torque. Same goes for a motor with a big cam built for high RPM- generally low RPM power suffers. You may just need a new intake and flat tappet cam, which would be cheaper than a high end carb. More info on the motor would help...


      I know it isn't a carb issue per se. But I am still trying to get an idea on what people suggest.

      Big block with a huge high RPM cam, an open plenum Weiand intake and an 850 AED carb. Carb has been set up to flow at a little over 900 cfm. The engine dyno'd at 589hp as is. HP is fine, but the set up and parts selection is way too much for the street. I was hoping to get away with a intake and carb swap, but the more I drive it, the clearer it has become that I must do a cam as well. I have consulted with Competition Cams as they did the custom grind on the cam that is in the engine. I want to find something compatible with the rest of the engine, heads etc. I have done that now. New cam on order, as well as a Edelbrock RPM intake. Still unsure what I should get for the carb though.

      Glenn



      Glenn

      1955 Chevy BelAir
      1951 Chevy 3100
      1987 Chevy Silverado

      My last project....
      https://www.pro-touring.com/threads/...my-72-Maverick!!

    10. #10
      Join Date
      Mar 2008
      Location
      Chicago suburbs
      Posts
      667
      Country Flag: United States
      Sounds like a pretty stout big block! What makes you think that you can't use the AED that you have now? Is it a mech. secondaries? For that motor it would probably be best. If you are asking for suggestions, I would say the best carb will be one custom built by someone like Pro Systems. The next best thing would be to tune what you have now VIA a wideband O2 gauge.

    11. #11
      Join Date
      Aug 2004
      Location
      Honolulu, Hi
      Posts
      163
      Country Flag: United States
      See you have sold the car, never mind
      good day.........

    12. #12
      Join Date
      Mar 2011
      Location
      Ca
      Posts
      336
      Country Flag: United States
      take a look at FITech, its worth it, but if you're set on a carb i wouldn't go smaller than a 750 with any kind of work done to a big block, you may want to consider an HP series type of carb, or if you have the specs of your motor you can always have a carb custom built to your motor which is usually what i do with high performance stuff, they just run better than an out of the box carb.







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