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Help Chosing A Carb

  • Thread starter Thread starter Live2shred303
  • Start date Start date Nov 11, 2012

Live2shred303

New Member
Jul 20, 2012
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Nov 11, 2012
#1
  • Nov 11, 2012
  • #1
im trying to pick out a carburettor from summit racing.
all of them are either electric or manual choke.
i need a vacuum choke.
it says secondary type: vacuum.
does that mean you can do either or?
 

Tim65GT

Active Member
Feb 24, 2004
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West Texas
Nov 11, 2012
#2
  • Nov 11, 2012
  • #2
Electric choke models use a heating element in the choke housing that slowly heats and a bi-metalic coil spring opens the choke plate. Manual choke model needs a cable to operate.

The vacuum secondary refers to the method that opens the secondary throttle blades - it has nothing to do with choke.

I'm not sure if new carbs are offered with a "vacuum choke" which uses vacuum to pull exhaust manifold heated air into the choke housing.
 

horse sence

15 Year Member
Nov 29, 1999
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Wile Coyote's stunt double
Nov 11, 2012
#3
  • Nov 11, 2012
  • #3
Live2shred303 said:
im trying to pick out a carburettor from summit racing.
all of them are either electric or manual choke.
i need a vacuum choke.
it says secondary type: vacuum.
does that mean you can do either or?
Click to expand...
i am assuming you are looking at the holleys. the electric choke would be the best
and vacume secondaries probably 600 cfm .
 

rbohm

Founding Member
Apr 12, 2002
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tucson,az
Nov 12, 2012
#4
  • Nov 12, 2012
  • #4
Live2shred303 said:
im trying to pick out a carburettor from summit racing.
all of them are either electric or manual choke.
i need a vacuum choke.
Click to expand...

i have never heard of a vacuum choke carb. a vacuum pull off for the choke has been used in the past though. every choke system i have ever seen is either manual of some form of heated bimetalic spring system. some are electric, some are water heated, and some are exhaust heated. the electric choke system is the most reliable and user friendly system.

it says secondary type: vacuum.
Click to expand...

this type uses the vacuum created in the primary venturies, or the weight of incoming air to open the secondaries. this is best for a street engine.
 

Realmongo

I prefer to be called "Evil Genius"
Founding Member
Oct 10, 2001
2,468
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Western Mass
Nov 12, 2012
#5
  • Nov 12, 2012
  • #5
Have you already tried the Holley Carb selector?

http://www.holley.com/applications/CarburetorSelector/CarbSelection.asp
 

clement

Founding Member
Feb 27, 2001
1,106
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Oak Cliff
Nov 14, 2012
#6
  • Nov 14, 2012
  • #6
i dont know what the combination is, but if its even a stock 289/302 and i needed a choked carb i would run an electric choke quick fuel ss series 650 double pumper. my early car had hwy gear and a stock converter with a stock 289 and even with the lightest spring in the vac secondaries it never even came close to a bog. so 4150 all the way.
 

zookeeper

Founding Member
Aug 25, 2001
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Rogue River, Oregon
Nov 19, 2012
#7
  • Nov 19, 2012
  • #7
I've always felt the 600cfm Holley 1850 is a great carb for a mild small blocks. But in the true spirit of hypocrisy, I run a pair of 390 cfm Holleys on my small block, so what do I know?
 

horse sence

15 Year Member
Nov 29, 1999
12,178
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Wile Coyote's stunt double
Nov 19, 2012
#8
  • Nov 19, 2012
  • #8
i have always ran holleys ,but get a holley trick kit .you can fine tune the accelerator/
when it opens and how much. change the accelerator pumps out with the green alcohol pump. the black pump get stiff and doesnt work well after a while, the green ones last forever and stay soft. durring winter and cold wheather the black pumps hardly work at all and sometimes make it hard to start.
 

hipo_p51

Member
Jun 13, 2008
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Nov 20, 2012
#9
  • Nov 20, 2012
  • #9
650 CFM Mechanical Street HP Carb
 

woodsnake

15 Year Member
Jan 16, 2007
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Hicksville, NY
Nov 23, 2012
#10
  • Nov 23, 2012
  • #10
I have the Edelbrock dual quad on my 68/289....It does OK with the progressive linkage. Although, I would also recommend a 600-650 Holley as well.
 
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