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Old 04-10-2013, 07:28 AM   #1
503swb
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how much cfm carb for 454??

Im about to replace my carb on my 81 c10. I have a 454 in there. What cfm carb should i get? Im want an edelbrock carb.
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Old 04-10-2013, 07:41 AM   #2
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Re: how much cfm carb for 454??

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Im about to replace my carb on my 81 c10. I have a 454 in there. What cfm carb should i get? Im want an edelbrock carb.
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need more info...
what cam do you have? headers? is this a daily driver? what are your driving habits? do you want fuel economy or more power?
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Old 04-10-2013, 08:45 AM   #3
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Re: how much cfm carb for 454??

So many factors needed, so few given. 750 should suffice, but may not be needed. Im am not a fan of Edelbrock carbs, so I have no advice on which particular one. I ran a Holley 850 Street HP on my mild 468. It was a little more than I needed, but jetted it accordingly. We need more details.
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Old 04-10-2013, 09:20 AM   #4
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Re: how much cfm carb for 454??

I am running a 650 cfm on a mostly stock '74 454 witha SM-465 and 3.73 gears. So far it is working out ok, but I just use it as a driver. Throttle response is good and there is not the smell of unburned gas.

My grandson is running a 750 on a slightly modified 454 and it is working out real well.

My son is running a 850 on a highly modified 454 and he likes the way it is working.

Like stated before it depends on how the engine is built and how you drive it.
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Old 04-10-2013, 01:55 PM   #5
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Re: how much cfm carb for 454??

....

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Old 04-10-2013, 01:58 PM   #6
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Re: how much cfm carb for 454??

Honestly i dont know much about the engine as i haven't done anything to it. Im pretty sure the cam has been changed to bigger than stock. I currently have no headers on there but plan on getting some and it isnt my daily. I prefer more power over fuel economy. Hope that helps
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Old 04-10-2013, 05:21 PM   #7
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Re: how much cfm carb for 454??

put a 750 with vacuum secondaries on it, buy a secondary spring kit and put the black spring in it
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Old 04-10-2013, 06:15 PM   #8
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Re: how much cfm carb for 454??

I have a mild 454 in my car with an Edelbrock 600. I needed a carb, buddy had one to use. I works OK, but trying to get money for a 3310. If it's stock or slightly above, a 600 will work fine. My last truck had a 600 and was friggin awesome. Only need a big carb if your gonna be turning high RPMs.
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Old 04-10-2013, 06:38 PM   #9
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Re: how much cfm carb for 454??

http://www.4secondsflat.com/Carb_CFM_Calculator.html
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Old 04-10-2013, 07:12 PM   #10
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Re: how much cfm carb for 454??

Find any edelbrock carb on Craigslist and slap it on. They all run about the same.
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Old 04-11-2013, 03:27 AM   #11
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Re: how much cfm carb for 454??

I was thinking of going with a 750 cfm
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Old 04-11-2013, 05:02 AM   #12
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Re: how much cfm carb for 454??

Try http://www.gtsparkplugs.com/CarbCFMCalc.html
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Old 04-11-2013, 06:31 AM   #13
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Re: how much cfm carb for 454??

I had a 750 Holley on my 454, it was too small...no matter what jets, squirters, cams or springs I put in there, could not get it to perform correctly. Just purchased an 850 double pumper, it should do the trick.
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Old 04-11-2013, 07:21 AM   #14
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Re: how much cfm carb for 454??

As long as it's mild, a 650 is fine.
Edelbrock carbs are old school, old tech. Get a Holley and let 'er eat.
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Old 04-11-2013, 01:25 PM   #15
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Re: how much cfm carb for 454??

I'm running an e-brock 750 cfm on a Buick 455 at the moment. The factory carb for the big blocks back in the day was either 750 or 800 cfm depending on the make and year.

I personally love e-brocks since they don't have issues with leaking like q-jets and aren't as temperamental as holleys.
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Old 04-11-2013, 01:39 PM   #16
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Re: how much cfm carb for 454??

ci. x max rpm / 3456 ex. 454 x 6500 = 2951000 / 3456 = 853.87 cfm. I haved used this equasion many times and is very accurate. GOOD LUCK
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Old 04-11-2013, 01:55 PM   #17
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Re: how much cfm carb for 454??

Most calculators will say 725 cfm for a stock street vehicle and 950 or so for a race vehicle. The formula above basically splits the difference and is used as the general reference point to choose from.

I just go by what the factory put on it since that's what the intake manifold was designed to flow.

Also remember that smaller carbs generally have better throttle response but kill the top-end. I've seen people running 454's with 500 cfm carbs just because they're around town cars and never get rev'd above 4k rpms. I've also seen 1,100 cfm carbs used because the engine is running a 1/4 mile at a time and lives most of its life in a trailer.

Hopefully that info makes it as clear as mud for you
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Old 04-11-2013, 10:08 PM   #18
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Re: how much cfm carb for 454??

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ci. x max rpm / 3456 ex. 454 x 6500 = 2951000 / 3456 = 853.87 cfm. I haved used this equasion many times and is very accurate. GOOD LUCK
go ahead and run an 850 on a street 454, let me know when you get tired of horrible mileage no throttle response and fumes burning your eyes, now ask me how i know? mine has a 670 on it now and it is soooooo much better!

and a 6500 rpm redline in a 454? that motor would be borderline streetable at best! this guys max rpm is probably more like 5500, maybe! i have a .060 over 396 that has a 7000 rpm redline and my 850 dp was too much carb
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Old 04-27-2013, 01:17 PM   #19
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Re: how much cfm carb for 454??

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ci. x max rpm / 3456 ex. 454 x 6500 = 2951000 / 3456 = 853.87 cfm. I haved used this equasion many times and is very accurate. GOOD LUCK
It wrong. That is what you are doing.
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Old 04-27-2013, 03:12 PM   #20
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Re: how much cfm carb for 454??

No real builder follows that old 60s carb formula anymore. Also bigger carbs don't make your engine run richer
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