650 cfm too much?

[Saetun]

For an otherwise stock 318? came across a used Holley 7855 (PN 0-80555C) for a pretty decent price. Looking for an upgrade to the stock Carter 2bbl, but really in no hurry. Was originally thinking more of a 600cfm since i only intend to bolt on mild upgrades at best. (4bbl, alum intake, 340 cam & headers) Thx.

~Jeff

 

[72bluNblu]

A 650 is probably a little large for an otherwise completely stock 318. But with a 340 cam and headers its not bad at all. It also depends on what you're using the car for. If its strictly a street driver, a 600 would probably be a little better fit.

But that doesn't mean a 650 won't work for you. I run a Carter 625cfm carb on my 318, which has only has a Streetmaster 318 intake, headers and what I assume is a stock, or very close to it, cam. I played with the jets and rods a little, and it runs just fine. Good response, great top end. I'd probably get slightly better gas mileage out of a 600, but I think from a performance standpoint it does just fine.

 

[67Dart273]

I Googl'ed that Holley number, and it comes up as "vacuum secondary." I really don't care for Holley spread-bore carbs, but I'd bet it will work OK

 

[Saetun]

A 650 is probably a little large for an otherwise completely stock 318. But with a 340 cam and headers its not bad at all. It also depends on what you're using the car for. If its strictly a street driver, a 600 would probably be a little better fit.

But that doesn't mean a 650 won't work for you. I run a Carter 625cfm carb on my 318, which has only has a Streetmaster 318 intake, headers and what I assume is a stock, or very close to it, cam. I played with the jets and rods a little, and it runs just fine. Good response, great top end. I'd probably get slightly better gas mileage out of a 600, but I think from a performance standpoint it does just fine.

Yeah, it will only be a street driver.... I apreciate the input. i think ill continue to look for a 600 to fall into my lap. like I said, it will be a mild build & i think with what I have in mind, the 600 probably would work best. thx all.

 

[rapidtransitric]

rule of thumb has been to multiply your cubic inches by two to get the right carburetor size. this would be adiquate for a mild setup if you were into the fine tuning of carbs you could really dial it in by changing jets, power valves, shooters, whistles, springs ,cams ,accelerator pumps ect