Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine> Real carb flow rates?
User Name
lost password?   |   register now

Thread: Real carb flow rates? Reply to Thread
Send Trackbacks to (Separate multiple URLs with spaces) :

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Additional Options
Miscellaneous Options

Topic Review (Newest First)
07-12-2010 08:46 PM
cobalt327 There is more to airflow than just quantity.

A high RPM engine will often "like" a bigger carb than the formulas call for, because it delivers a better quality of air/fuel than a small carb will.

If the flow is TOO fast through the venturi, the carb will go pig-rich and the a/f mixture will be bounced off of the plenum floor, etc. This causes all sorts of distribution and a/f separation issues.
07-12-2010 08:29 PM
kleen56 Wow, interesting statement by DoubleVision. I always heard growing up and at street races, that bigger is better including CFM on carbs. Friends use to run a 720 Holley on a 289 Ford and the engine would run like nobodies business. I'm running a 650 DP Holley on a SBF that requires only 480 CFM, The engine runs well under all conditions. I did have to drop the jet sizes a bit but that was it. I get good mileage as long as I don't open the secondaries.
07-12-2010 08:17 PM
DoubleVision Carbs work on the same principle. Lets say a carb is rated at 700 CFM. We stick it on a high performance 350. We do tests and find the engine only wants 585. The engine runs perfect and has great power, but since the engine only demands 585 should we swap the carb for a smaller one? not really, why is because a carb will only feed a engine what it demands.
Some believe because it`s flow rate is 700 means at wide open throttle it`s flowing 700 like it or not and that`s not the case. If the engine can`t pull it in then it`s not being used. In the real world, Engine demand figures and carb sizes are out to lunch. Even during the horsepower wars of the 50`s and 60`s a 283 with power pack heads that had puny 1.71 valves but yet had a good sized cam, high compression and other goodies came with two four barrels, what was the chance of a 283 using that much CFM? not much.
07-12-2010 06:51 PM
Real carb flow rates?

Anybody know the real flow numbers for carbs? People are telling me a 800 EPS edelbrock flows 650cfm. Demons 650 DP flows 800cfm. Are these truth?

Doesn't a 770 Sa Holley flow 770cfm?

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -6. The time now is 09:55 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.