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Discussion Starter #1
I was wondering what the CFM rating of a holley 3310 750 is on just the primaries? Ive been looking all over the internet with no definitive answer. I would guess that since the primary and secondary blades are the same size then each side makes up one half of the CFM rating. So then each sides would flow 375 CFM, but I have no idea if this is correct.

Thanks
-Dan
 

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the 750 rating is thru the entire carb, all four barrels
What does that have to do with the question he asked?
He wants to know if the primary side flows half of the total CFM. Or....?
I don't know the answer either. I would call a Holley tech, but it's unlikely they know the answer.
 

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Discussion Starter #4
the 750 rating is thru the entire carb, all four barrels.
Yeah, I was curious what the CFM rating is for just the two front barrels (primaries). For instance, if I disabled the secondaries from opening, would it esentailly turn the carb into a 2 barrel that flows 375 cfm?

I ask because I may want to limit the power it can produce when my friend borrows the car this weekend :rolleyes:. I trust him, just not that much I guess.

-Dan
 

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I ask because I may want to limit the power it can produce when my friend borrows the car this weekend :rolleyes:. I trust him, just not that much I guess.

-Dan
Disable the secondaries and back the time off a couple of degrees. You may want to pull a couple of plugs too. :D
 

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Discussion Starter #6
What does that have to do with the question he asked?
He wants to know if the primary side flows half of the total CFM. Or....?
I don't know the answer either. I would call a Holley tech, but it's unlikely they know the answer.
Thanks bowtie. Ill give them a call anyway to see if they know. I might get lucky.

Disable the secondaries and back the time off a couple of degrees. You may want to pull a couple of plugs too. :D
lol, I thought about that but hes a good guy. The car doesnt make a ton of power by any means, its just more then hes used to. I put the 4100 rpm rev limiter in the MSD box too :D.
 

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limit the carb..

Yeah, I was curious what the CFM rating is for just the two front barrels (primaries). For instance, if I disabled the secondaries from opening, would it esentailly turn the carb into a 2 barrel that flows 375 cfm?

I ask because I may want to limit the power it can produce when my friend borrows the car this weekend :rolleyes:. I trust him, just not that much I guess.

-Dan
Put a block of wood under the gas pedal :devil:
 

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Hello,


Im just guessing but I think typically Holley rates most 2 bbls at a higher depression than a 4 barrel.

Again, just guessing its because you have less of an aperature with a 2 barrel than a 4 barrel with all of the respective throttle plates open.


I guess a comparision might be a 500cfm 2 bbl to a 500 cfm 4 barrel. My guess is that the 4 barrel would flow more tha than the 2 at the same depression?


Sound close?


Maybe?




Jeff
 

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Discussion Starter #9
Put a block of wood under the gas pedal :devil:
lol, Maybe 1/2 inch of travel in the pedal will be enough. Ill get a 2x4 and saw and get to work. Do you think some bailing twine will hold in on? :cool:

Hello,


Im just guessing but I think typically Holley rates most 2 bbls at a higher depression than a 4 barrel.

Again, just guessing its because you have less of an aperature with a 2 barrel than a 4 barrel with all of the respective throttle plates open.


I guess a comparision might be a 500cfm 2 bbl to a 500 cfm 4 barrel. My guess is that the 4 barrel would flow more tha than the 2 at the same depression?


Sound close?


Maybe?




Jeff
Hmm, sounds good enough to me lol. I emailed holley, maybe they can educate me on their CFM rating system.

-Dan
 

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What does that have to do with the question he asked?
He wants to know if the primary side flows half of the total CFM. Or....?
I don't know the answer either. I would call a Holley tech, but it's unlikely they know the answer.
my bad...don't have to get all pissy now....
 

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the 3310 holley vac. sec., if it's an early one, a -1 on the chocke horn, is actually a 780 cfm carb and all the other ones are 750's, and yes the front 2 barrels are half of the total cfm rating....

jon
 

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Discussion Starter #12
the 3310 holley vac. sec., if it's an early one, a -1 on the chocke horn, is actually a 780 cfm carb and all the other ones are 750's, and yes the front 2 barrels are half of the total cfm rating....

jon
Ok thanks. Im almost positive it is a 750 3310 because thats the type of base plate that is on it. The body has the choke horn milled off so I cant be 100% sure which body is on it.

-Dan
 

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Im pretty sure that if its an older 780 style 3310 it will have droped boosters.


iI it has straight boosters its probably rated at 750.


Im not sure but I think both sizes use the same throttle blade sizes.


The eary carb, the 780 version of the 3310 is one of my fovorite carbs.
 

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I've worked on a few of the early 780's and some of them have adjustable idle air bleed channels located in the main body near the choke tower-I wish that feature would have carried on. Nice carb.
 
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