Well yes and no. What you've done is allowed the engine to use what it needs. If your engine is built to run, lets say, 900 cfm, then it will only use 900 of the available 1200 CFM. On the one 600 it will be using almost or all of the 600, but once you add the second one , needing only 900, it will only use what it needs of the two. That is the simple answer. There are more involved issues as you add carburators too. Responce thru the throttle bores/venturies of a single carb (especially of smaller cfm than the engine wants) compared to having four more throttle bores to slow things down/lessened vacuum signal. Then you have the issue of the engine needing 1200 cfm but is the manifold of such design that it flows it smoothly, efficiently, is there reversion dilution of the intake charge because of cam timing versus runner length versus plenum size/design, versus throttle bore alignment with the runners under the plenum. Many different issues to look at but the first sentence is the most simple. Sorry if I got carried away there. Mark L
Question about cfm
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All normally aspirated engines are much different than supercharged engines. Reason being that a supercharger pushes so much more fuel and air into the cylinders that it creates a scenario that's much like adding both cubic inches and compreession to the engine. What would work well, or even over carburate a normal engine will be much less than a supercharged engine needs.
There's also much more to it than just adding cfm to a supercharged engine, although that's a good start. Jetting, nozzles, and (if it's a Holley) power valves, all need to be adjusted to make it work right. There's actually a formula that really good blower guys have to figure out the size blower, the pulley size, and carbs/tuning needed to make it all work well. I spoke with my friend Gale Plummer of Plumb Crazy Blowers, and when he starts talking about all the various numbers, etc. it makes my head hurt!
There's also much more to it than just adding cfm to a supercharged engine, although that's a good start. Jetting, nozzles, and (if it's a Holley) power valves, all need to be adjusted to make it work right. There's actually a formula that really good blower guys have to figure out the size blower, the pulley size, and carbs/tuning needed to make it all work well. I spoke with my friend Gale Plummer of Plumb Crazy Blowers, and when he starts talking about all the various numbers, etc. it makes my head hurt!
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