Thread: Air gap manifold question

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If your running a small block, they usually just run off of the rear carb till half throttle. Big block, on the other hand, need to run one to one linkage, otherwise the front cylinders run hot. Edelbrock uses 500 carbs for small blocks and 600 carbs for big blocks.

I run 600 carbs on my 454 with one to one linkage.

Originally Posted by gassersgarage

If your running a small block, they usually just run off of the rear carb till half throttle. Big block, on the other hand, need to run one to one linkage, otherwise the front cylinders run hot. Edelbrock uses 500 carbs for small blocks and 600 carbs for big blocks.

I run 600 carbs on my 454 with one to one linkage.

I don't think he needs a 1,000 cfm for a 5,000 rpm engine.

A street driven car needs heat and small carbs. Two 600 cfm carbs even with a progressive type linkage is way too much. A single 500 CFM on a 350 is just about right for 90% of driving, with a 600 as a nice choice when you want to kick it in the butt:

Size = (Engine CI x RPM) /3456 X Volumetric efficiancy

= (350 x 6000) / 3456 x .85

= 516 CFM TOTAL !!!!

Most engines without major mods wont have a VE (Volumetric Efficiency) much greater then 85 - 90%. Seldom will you be running at 6000 RPM. Choose your carbs accordingly - but a FI setup would be a better choice.

He definatly does not need 1200 cfm either........

I know I will get flac over this suggestion ,but its a good one ,just not as impressive.......I would use the adapters and run 2 big 2 barrels on that manifold ,under the aircleaner they will be mostly hidden anyway.A couple of 350 cfm 2 barrels or in that range ,maybe a pair of 300s.........Then use non progressive linkage,both open and close at the same time.
Some thing like this......Holley 0-807871 High Performance Race 350 CFM 2-Barrel Carburetor.
Amazon.com: Holley 0-807871 High Performance Race 350 CFM 2-Barrel Carburetor: Automotive

This is a list from the Holley web site:

Holley Performance Street Performance – Traditional Products

Look at p/n 0-8007. It's a 390 CFM !!!!
* Vacuum Secondaries
* Power Valve Blow-out Protection
* 100% Wet-Flow Tested
* Model 4160 W/Side Hung Floats
* Calibrated for Small V8 or 6-cyl Engines
* 2x4 Street Tunnel Ram Carb
* Ford A/T Kickdown
* Electric Choke
* Includes Single Inlet Banjo Fitting

WOW,I never knew you could get a 4 barrel that small......
You could run those non progressive too!!!!!!!!
I think those are perfect for your engine...........
With the non tunnel ram intake and those carbs ,it should be a walk in the park.....

Originally Posted by shawnlee28

WOW,I never knew you could get a 4 barrel that small......
You could run those non progressive too!!!!!!!!
I think those are perfect for your engine...........
With the non tunnel ram intake and those carbs ,it should be a walk in the park.....

At $347 EACH from Summit .

Oh well it's only money. I used to run 750CFM 3310's and they are $270 ea and the good ol' 600 cfm 0-1850s are $250 ea

Thanks for all the replies.

I'm still in "thinking" mode on the engine for this project, but I know I want multiple carbs just for the look. I know, I know that's probably not a good reason, but you gotta admit, they sure do look cool.

My original plan was 3 dueces because I'm running a set on my 46 and know how to make them work. Price wise, either setup is about the same. Actually, the 2x4 may be a little cheaper.

The dual quads sound like a real challenge, but I'm crazy enough to take on a "lost cause" challenge every now and then.

and thats like saying my 302 doesnt need 750,


[QUOTE=IC2]A street driven car needs heat and small carbs. Two 600 cfm carbs even with a progressive type linkage is way too much. A single 500 CFM on a 350 is just about right for 90% of driving, with a 600 as a nice choice when you want to kick it in the butt:

Size = (Engine CI x RPM) /3456 X Volumetric efficiancy

= (350 x 6000) / 3456 x .85

= 516 CFM TOTAL !!!!
[QUOTE]