which carb.?

[charger10]

I have a '67 charger with 440 mild modified. 446ci.,440 source heads, performer intake, cam 274-286, auto trans., suregrip 3.55, headers. I have little experience with carbs. use will be mainly street, but strip a couple times a year. I was thinking holley street avenger 750, but friend said holley 650 double pumper. any advice would be appreciated.
thanks, bruce

 

[Woodruff Carbs]

You are on the right track. I would use a 750 vacuum secondary.

 

[moparpromo]

minimum 750 double pumper. 4779 preferably

 

[rumblefish360]

750 for sure.

 

[Bill Monk]

I like the street avenger. I ran one on a 340 cuda. Easy tunability and access to the vac spring. 750 for sure

 

[440Coronet500]

Edelbrock 1407 750 cfm. 440'

 

[WileERobby]

Holley 3310

 

[road chicken]

750 Street Demon

 

[RJRENTON]

My opinion....
HOLLEY R-3310-1 Model 4150 vacuum secondary. This is the first generation of the origional R-3310 developed for, I believe, GM's 427/425 L-88 engine. The later variations, are 4160 design and re-rated at 750 CFM.
Years ago I had a 71 Dodge Charger 500, WP23U1A****** with a 440/375 hp, 727B and 4:10 8 3/4" rear end which I retrofitted with an Edlebrock (aka "Eddy") Torquer II manifold (X shaped runners with an open plenum) and the Holley R-3320-1 carb. Great response fairly ok fuel mileage....~ 12-14 MPG. I'm not a real fan of double pump carbs....too easy to add too much carb at the low end....just my opinion of course.
BOB RENTON

 

[charger10]

My opinion....
HOLLEY R-3310-1 Model 4150 vacuum secondary. This is the first generation of the origional R-3310 developed for, I believe, GM's 427/425 L-88 engine. The later variations, are 4160 design and re-rated at 750 CFM.
Years ago I had a 71 Dodge Charger 500, WP23U1A****** with a 440/375 hp, 727B and 4:10 8 3/4" rear end which I retrofitted with an Edlebrock (aka "Eddy") Torquer II manifold (X shaped runners with an open plenum) and the Holley R-3320-1 carb. Great response fairly ok fuel mileage....~ 12-14 MPG. I'm not a real fan of double pump carbs....too easy to add too much carb at the low end....just my opinion of course.
BOB RENTON

thank you for all the advice. I am at 5000 ft. elevation. will I have trouble getting enough air in to match the fuel?

 

[moparpromo]

thank you for all the advice. I am at 5000 ft. elevation. will I have trouble getting enough air in to match the fuel?

no matter the elevation, you'll need to tune any carb to match your combo. Remember, carbs don't "force" air or fuel into the engine. The only fuel that is "put" in the engine is the accelerator pump. Other than that, it's syphoning from the motor that determines the amount of flow.

 

[RJRENTON]

thank you for all the advice. I am at 5000 ft. elevation. will I have trouble getting enough air in to match the fuel?

Usually, for high or higher altitude operation, the carb requires a slightly LEANER fuel mixture. For a Holley carb, perhaps 2-3 jet sizes SMALLER than stock or sea level operation. For a Carter or Edlebrock ("eddy") carb, perhaps slightly LARGER metering rods or A SMALLER main jets. Look at spark plug coloration or if you have access to an exhaust gas analyzer to check for proper mixture. Spark advance MAY need re-adjusted as leaner mixtures burn slower, so slightly more advance MAY be needed. Again, just my opinion of course.
BOB RENTON

 

[68Moparmaniac]

Living in Utah with elevation changes in every direction I decided to move away from the old toilet bowl and onward into the 21st century. I want to be able to drive my car where I want to go and if I want to drive up to Park City (additional 1400 ft from where I live) I want to make it up there without looking like a chipped up Diesel. I'm still in process of installing the 1000 CFM multi port Edelbrock EFI on my 440 so I can honestly say "I don't know if its better or not" but I like the ability to tune on the fly without even popping the hood, a very attractive option in my opinion.
Mostly agree with everyone here about carb size, 750 works pretty good on a mild 440. This is one of those situations where bigger isn't necessarily better...
I was always pretty close with my rule of thumb for Holley's, for every 500 ft. of elevation was a jet change from my basic tune.
If your looking for a 750 vac. secondary carb I have some on the shelf if your interested. Even have a 650 DP....
Good luck

 

[charger10]

thanks for all the help.

 

[RJRENTON]

no matter the elevation, you'll need to tune any carb to match your combo. Remember, carbs don't "force" air or fuel into the engine. The only fuel that is "put" in the engine is the accelerator pump. Other than that, it's syphoning from the motor that determines the amount of flow.

Re fuel that is "put" into the engine by the accelerator pump...YES.
In essence, the carb works on the differential pressure principal....that is, fuel is not siphoned but is forced into the air stream by the pressure DIFFRRENCE in external air pressure (atmospheric pressure or absolute pressure) and the low pressure created in the carbs venturii and the NEGATIVE PRESSURE in the intake manifold (or below the throttle plates when closed), controlled by the various metering elements of the carb...jets and or metering rods.
BOB RENTON

 

[moparpromo]

Re fuel that is "put" into the engine by the accelerator pump...YES.
In essence, the carb works on the differential pressure principal....that is, fuel is not siphoned but is forced into the air stream by the pressure DIFFRRENCE in external air pressure (atmospheric pressure or absolute pressure) and the low pressure created in the carbs venturii and the NEGATIVE PRESSURE in the intake manifold (or below the throttle plates when closed), controlled by the various metering elements of the carb...jets and or metering rods.
BOB RENTON

yeah, a lot of ways to say it, but at the end of the day, your pistons pull air, suck air, syphon air, which pulls the fuel with it.

 

[rumblefish360]

The engine creates a vacuum and it isn’t necessarily all due to the piston dropping in the bore. Actually, that has about near zero to do with it on drawing on the carb to get fuel flowing.

The pressure differential is the reason. Fuel is Siphoned not forced. Forced fuel is super charging/injection.
As the air is at a higher pressure above the carb, it is draw into the carb due to the lower pressure area under the carb. The air flowing through the carb drags the fuel out of the carb. (AKA Siphon)

In no way shape or form is the fuel forced out of the carb.

 

[RJRENTON]

The engine creates a vacuum and it isn’t necessarily all due to the piston dropping in the bore. Actually, that has about near zero to do with it on drawing on the carb to get fuel flowing.

The pressure differential is the reason. Fuel is Siphoned not forced. Forced fuel is super charging/injection.
As the air is at a higher pressure above the carb, it is draw into the carb due to the lower pressure area under the carb. The air flowing through the carb drags the fuel out of the carb. (AKA Siphon)

In no way shape or form is the fuel forced out of the carb.

YES.....well put for those who may not understand the DIFFERENTIAL PRESSURE principal. Its the DIFFERENCE in pressure gradient, high pressure (air outside the carb) to low pressure (carb's fuel delivery systems). In order to INCREASE a pressure gradient, low presdure to high pressure, some form of work or energy input must be involved. For example, a compressed air system, where the energy source is the electric motor.
BOB RENTON

 

[moparpromo]

didn't I say siphoned in an earlier post??? Like post 16 ?

 

[WileERobby]

I'm also a fan of the thermoquad. The earlier ones.