Carb size for mild 440

[Garrett Ellison]

Yes, that’s plenty of carb, especially if it has the factory iron intake

 

[Brooks James]

In keeping with our recent trend I respond ....

Rumblefish you ignorant slut !
Isnt that what I just said ?
And what constitutes a spread bore if it's not the venturis being of different size ?

You youngens may not understand my opening volley ...lol

"Jane you ignorant slut" from Saturday Night Live

 

[rumblefish360]

Actually I do want to know why the AVS2 650 would not qualify as a spreadbore. Curious...

Expand the below quote from myself.

Sorry my brother but this is incorrect. Yes! Even though the primary and secondary throttle plates show a difference in sizes, this is still not considered a spread bore carb.

The TQ & QJ are spread bore carbs. There, the difference is obvious.

Its not a spread bore with a small difference in sizes between the primary and secondary bore but the huge difference between them. See the TQ below.

The industry made this distinction decision long ago.
The secondaries are spread out wider than the standard square bore intakes would allow the carb to be bolted onto the intake. They had to spread the secondary bore to meet the more spread out width of the secondaries of the new carbs. The QJ & TQ. Holley also has spreadbore carbs like below in vacuum & mechanical secondary. 4160 & 4150 styles as well as the defunct two piece design now carrying the Summit logo. Those were the 4010 & 4011 series carbs, FWIW. They were good units.

 

[Garrett Ellison]

Yes, 4011. Here’s a marine 800 cfm V.S. example

 

[rumblefish360]

View attachment 1715810164 View attachment 1715810166 Yes, 4011. Here’s a marine 800 cfm V.S. example

I would like to get my hands on one of those. I had the smaller 650 spread bore aluminum Holley a ways back.

 

[Bewy]

I would stick with the 650 AVS2 for this application. Better to be under rather than over carbureted....

Spread bore. The name comes from the QJ with the huge secondary bores. The c/line of the sec bores had to be 'spread' to make room for the extra large t/blades.

 

[cpearce]

Thanks to all that responded, I will be sharing this information with my Buddy who ultimately will decide. I suspect he will lean towards the 650 due to type of usage of car. Really, at the end of the day I don't think he could go too wrong with either choice.

 

[cpearce]

I guess 440's were over carbureted from the factory.
carry on

Point well understood, however they also had better heads, more compression, higher flowing exhaust manifolds and camshafts than the one in question.

360's could be had in 4 barrel form in Dusters and Cuda's etc, as a performance engine. They could also be had with a 2 barrel in pickups and wagons. My point is, I feel carburetor choice is very dependant on application, as well as engine size.

No attempt at an argument here, but underlying the exact reason we asked the question.

 

[MOPAROFFICIAL]

If he drives and shifts under 5,500

A plain old 600cfm will be great.

If he spends time mostly in the 3800-6000 rpm 'freeway/passing gear'.. 700cfm or more.

 

[mbaird]

Expand the below quote from myself.


Its not a spread bore with a small difference in sizes between the primary and secondary bore but the huge difference between them. See the TQ below.

The industry made this distinction decision long ago.
The secondaries are spread out wider than the standard square bore intakes would allow the carb to be bolted onto the intake. They had to spread the secondary bore to meet the more spread out width of the secondaries of the new carbs. The QJ & TQ. Holley also has spreadbore carbs like below in vacuum & mechanical secondary. 4160 & 4150 styles as well as the defunct two piece design now carrying the Summit logo. Those were the 4010 & 4011 series carbs, FWIW. They were good units.


View attachment 1715810112 View attachment 1715810115

That sounds plausable... and since you stated with such conviction I will buy it .
Lol

 

[mbaird]

The smaller carb will put a smile on his face every time he starts to accelerate. The bigger carb will make him smile a little more on the rare ocassions that he goes WOT.