500cfm edelbrock or 600 cfm holley??

[Chevymanforlife]

found a awesome deal on both i need your guys advice which one is better it will be going on my 305 build with a edelbrock performer intake i have a bigger cam in it to duration 262/270 lift 462/480 im thinking im better off with the holley but want to hear what you guys think thanks

 

[74 Shortbed]

Use the one that you're familiar with and know how it works, because no matter which one you use you're gonna have to tune it to your application.

 

[Rusty Nail]

Holley>Edelbrock
600>500

 

[rich weyand]

A normally aspirated 305 can't pump more than 450 cfm at 5000 rpm, so either will do fine for volume.

Some people say the Edelbrock is better for street use, the Holley for track use.

Most carbs are more efficient running at a higher percentage of their rated cfm, because the stack velocity is up, which gives better carburetion and a more even mixture.

 

[Chevymanforlife]

gonna go with the holley 600 cfm just to be on the safe side if its to high i can turn it down thank you guys for your help!!!

 

[Rusty Nail]

Rich, I ....

 

[rich weyand]

Rich, I ....

Yes?

 

[Rusty Nail]

You're a good ol' boy Rich, I don't care what they say about ya!

You think he should run the 500 Brock, right?

 

[rich weyand]

Yeah. Everybody always wants to over-carb, and they get worse performance and worse mileage from the more expensive carb.

And then the next step is not to tune it properly with an A/FR meter, because it's too expensive, then bitch about how the new carb performs.

A 305 at 5000 rpm will pump about 435 cfm at a volumetric efficiency of 1.0, which he ain't gonna get. More like 400, if that.

Why over-carb the engine by 50%??? WTF do you think that buys you?

Oh, and if it's one of the Holleys with mechanical secondaries, when he punches it, the stack velocity is going to go to zero, the mixture will go dead lean, and the engine's gonna fall flat on its face.

But then he can go on the forums and bad-mouth the Holleys as crappy carbs.

<smh>

The thing about the Edelbrock is that it's pretty easy to tune. So once he does decide to get the A/FR meter and tune it, he has a chance of getting it right.

And any properly tuned carb will outperform one that isn't properly tuned.

 

[Rusty Nail]

It's the circle of life!

 

[rich weyand]

It's the circle of life!

 

[MikeB]

YA 305 at 5000 rpm will pump about 435 cfm at a volumetric efficiency of 1.0, which he ain't gonna get. More like 400, if that.

Why over-carb the engine by 50%??? WTF do you think that buys you?

Oh, and if it's one of the Holleys with mechanical secondaries, when he punches it, the stack velocity is going to go to zero, the mixture will go dead lean, and the engine's gonna fall flat on its face.

But then he can go on the forums and bad-mouth the Holleys as crappy carbs.

Yeah, but I know a guy who knows a guy who says a 350 needs at least a 750 cfm carb, so that means a 305 needs a 650 carb. So I'm going big!

Seriously, for a 305 I'd use the carb with the smallest primary throttle bores, probably the 500. And if it's a Holley 0-1850 or 0-80457 he's got, then that will work OK, too, but may give up some crispness at throttle tip in, and will make absolutely NO difference at WOT max RPM.

Then again, 74 Shortbed's advice to use what the OP is familiar with may be the best advice of all!

 

[rich weyand]

Seriously, for a 305 I'd use the carb with the smallest primary throttle bores, probably the 500. And if it's a Holley 0-1850 or 0-80457 he's got, then that will work OK, too, but may give up some crispness at throttle tip in, and will make absolutely NO difference at WOT max RPM.

Then again, 74 Shortbed's advice to use what the OP is familiar with may be the best advice of all!

I can't disagree with any of that.