SHEET METAL vs 4 BRL MANIFOLD
- Thread starter BAGN
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I'm not trying to hyjack your post but is it even fair to compare them?
The 4brl manifold would be designed with a typical application in mind. It was also disigned to pull around maybe 600 hp or so worth of air down vertically through the 4 venturies in a carb.
A sheet metal manifold can be custom built to your engine combo. Runner length size and shape, and plenum size and shape can all be tweeked to enhance the characteristics of YOUR engine on a dyno. If you buy one that isnt custom built and tweaked for you then it would come down to how wise or lucky of a choice you made in selecting one.
A manifold that flows 1500 cfm may make less power than one that flows only 1000 cfm. A motor isnt a flow bench or a fan that pulls this steady amount of air through it. An engine works off of pressure pulses and the frequency of the pulses changes with the rpms of the engine. Because of this you can select or modify certain componets (heads, cam, intake sys, exh sys ect) to basically "tune" a motor to enhance its performance in a certain frequency range (aka rpm range). This is sort of a fancy way of saying you need a "matched combonation". One manifold could really boost the midrange torque on one motor and kill it on another.
You would have to get really specific about some ones set up AND the manifolds they tested to get a good idea of what could be expected.
Jason
p.s: I'm currently trying to figure out what to do myself. Ever since I seen that manifold Kendal made two years ago
The 4brl manifold would be designed with a typical application in mind. It was also disigned to pull around maybe 600 hp or so worth of air down vertically through the 4 venturies in a carb.
A sheet metal manifold can be custom built to your engine combo. Runner length size and shape, and plenum size and shape can all be tweeked to enhance the characteristics of YOUR engine on a dyno. If you buy one that isnt custom built and tweaked for you then it would come down to how wise or lucky of a choice you made in selecting one.
A manifold that flows 1500 cfm may make less power than one that flows only 1000 cfm. A motor isnt a flow bench or a fan that pulls this steady amount of air through it. An engine works off of pressure pulses and the frequency of the pulses changes with the rpms of the engine. Because of this you can select or modify certain componets (heads, cam, intake sys, exh sys ect) to basically "tune" a motor to enhance its performance in a certain frequency range (aka rpm range). This is sort of a fancy way of saying you need a "matched combonation". One manifold could really boost the midrange torque on one motor and kill it on another.
You would have to get really specific about some ones set up AND the manifolds they tested to get a good idea of what could be expected.
Jason
p.s: I'm currently trying to figure out what to do myself. Ever since I seen that manifold Kendal made two years ago
The reason i'm asking is because I am starting to get my duck in a row to build my motor. Its gonna be a street car (as in driving to Car Shows, Drag Strip & Burger Joint. Oh, And occasoinal sunny day to work) I already have a 4 brl converted to fuel injection. But I REALLY love that NASTY sheetmetal look. Anybody have any feed back.
