OK.....anyone in here know.....

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Feb 22, 2006 | 08:05 PM

EgoMan

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Fleet Mechanic

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From: Montana

OK.....anyone in here know.....

how many cfm a speed density system flows on a 92 351? This is the third forum I have asked in and I always get ignored so can someone please give me some insight here?

Feb 22, 2006 | 08:36 PM

Ford_Six

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From: The Big, Oregon

I'm going to guess it's around 450-500, I'm not really sure. I used to know of a cfm calculator online, but I can't find it now.

Feb 23, 2006 | 08:50 AM

EgoMan

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Fleet Mechanic

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From: Montana

lol thanks I still dont know I figure 600-700 you figure 450-500...someone else thought it was 800. Im not sure but atleast thanks for the reply.

Feb 24, 2006 | 07:14 PM

LxMan1

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From: Louisville,Ky.

The 5.0 Mustangs were about 600cfm. The trucks have a little better flowing lower intake so 650 to 700 would close.

Feb 24, 2006 | 09:14 PM

ratstang

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503 CFM at 5500 RPM and 90% VE. 447 CFM at 80% VE. You could get to 800 CFM but I'm guessing you'd have to spin it to about 8-9000 RPM. I think the piston speeds even at 5500 would be pretty high.

Feb 25, 2006 | 12:52 AM

LxMan1

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From: Louisville,Ky.

The question was what cfm does the intake manifold flow, not engine requirements.

Feb 25, 2006 | 01:41 AM

EgoMan

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Fleet Mechanic

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From: Montana

Wow thats deep....this is way different than carbs evidently.....usually I would rate my carb at 600cfm......am I asking the wrong question or is that just the way EFI is? Should I be asking.....what does a 56mm T-Body flow?

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Mar 2, 2006 | 05:04 PM

Jharger

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From: Phoenix

There is no direct comparison for a carb CFM rating and an EFI system. For a carb, the carb is the restriction. The rating follows an SAE set of assumptions/guidelines. And at normal atmospheric pressure, non-turbo or supercharger, it flows a max = the carb cating, 600CFM for example. That's all it means. Doesn't mean it flows that actually on a car - that all depends on displacement and RPM - as mentioned. For actually engine CFM, the previous descriptin is accurate. But trying to compare a carb to EFI for performance or efficience, I guess was the driver for this question, is to compare apples to oranges.

Mar 2, 2006 | 09:27 PM

#10

Ford_Six

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From: The Big, Oregon

Carb cfm is rated by flow at a fixed vacuum level below the carb, a throttle body can be measured the same way. This is not the same as the cfm required by the engine, it just provides a standard for measuring airflow.