I'm gonna get a holley double pumper but I need a reccomendation. It's a 74 corvette 350, agressive cam, 13.5:1 compression and 400hp. It was used in truck pulls. I saw on another post that 600 would be enough for this engine size, but will it be enough for MY engine?

 

I'd say 700. maybe 750.

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13.5 to 1 compression! HA! Good luck getting fuel for that thing.

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84 Camaro ZZ4 with HOT cam. 1.88 60' (12.98 @ 105MPH E.T.)
Other Mods: You name it and I have probably changed it.

2001 Dodge Ram Quad Cab 5.9L 4*2

ASE Certified Auto Tech
LIVE AND DIE BY THE ALMIGHTY BOWTIE!

 

13.5 what the hell kind of pistions/ heads do you have. 650 cfm is more than enough with a singel plane. you can run about 700 cfm with a dual plane. its been my experance the singel plans like a little less cfm so that they are more responsive.

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when the green flag drops the bull$hit stops

Curent: 350,performer RPM intake ,650dp, 700r4, headers, 3inch exhast
Spring 01: 406, Comp 282 solid cam, 2400 stall converter, every thing else the same.

 

The pistons are forged trw domes. The heads are stock 74 corvette. I know I'm gonna have to run race gas. I read on the hotrod site that high compression engines run best with single plane intakes,a monster carb and large tube headers.

 

Fan,
It will not be nearly enough. The following formula comes directly from Vic Edelbrocks catalogue:

CFM requirement = cubic inch displacement X max RPM X volumetric efficiency(%) divided by 3456.

Now, what ALMOST NOBODY mentions is that a correction factor exists for single plane and dual plane manifolds. It is: for single plane multiply by 1.1 to 1.3

For dual plane multiply by 1.2 to 1.5

So, presuming you have 1.00 VE since you have 13 to 1 compression, and presuming you'll have a redline of 6,500 RPM, using a single plane manifold, it goes like this:

350 X 6,500 X 1.00 div. by 3456 = 658 CFM

658 X 1.2(avg.) = 790CFM.

I'd use a 750DP or 800DP.

BOR

 

BOR, TELL ME MORE ABOUT THIS MAGIC CORRECTION FACTOR! I have never heard of such. Where did you find this data. Who can support your claim. If true this could shed light on the old carb size debate! Mentor me.

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84 Camaro ZZ4 with HOT cam. 1.88 60' (12.98 @ 105MPH E.T.)
Other Mods: You name it and I have probably changed it.

2001 Dodge Ram Quad Cab 5.9L 4*2

ASE Certified Auto Tech
LIVE AND DIE BY THE ALMIGHTY BOWTIE!

 

Hmmm. From that formula for my new engine, my 850DP Speed Demon is near the bottom end of what I need. Looks like I'll have to start looking around for a 1150 dominator. Or maybe a couple of 650's mounted on a tunnel ram. Mmmmm.

Nothing like having a race engine. It's hard to over carb it. 2 fuel curcuits. Idle and WOT.

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87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
454 Big Block almost ready for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
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87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

id say for that hot of a engine a deeply jetted 750 or stock 800. you need lots of fuel for that compression! forget what the math geek says,do like the old hotrodders do just guess and work from there!

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1989 firebird formula

Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 intake.

Future mods performer rpm air gap intake (polished) and 600 edlebrock carb, comp roller cam, and way better headsa 400 defintely in the works!

 

I run an 11.5:1 406 Small Block in my 63 Nova, and it is very therapeutic with just a 750 Double Pumper. The car will lay rubber in all gears. Because of the overlap in the solid-roller cam, it does fine on Premium pump-gas.

For your set-up stick with a 700 and get an aftermarket mechanical fuel pump to keep it full. It sounds like a slick dual-purpose car.