Patent ID: 6901898

Claim:
A variable runner length air intake manifold for an internal combustion engine having air intake valve inlets, said manifold comprising: a housing having fixedly attached upper and lower halves, said upper half including an air inlet portion and a plurality of air outlets, each of said plurality air outlets in communication with a corresponding one of the air intake valve inlets of said engine; a tapered drum having opposing ends disposed within said housing wherein one of said ends is open for receiving air from said air inlet portion and into said housing, said tapered drum operative to cooperate with said housing to form a plurality of runners, said tapered drum being rotatably mounted within said housing; a plurality of sealing ribs formed on an outer surface of said tapered drum that are spaced apart between said opposing ends wherein said tapered drum includes a plurality of openings formed through said outer surface and disposed between adjacent sealing ribs wherein each of said plurality of openings is in fluid communication with a corresponding one of said plurality of runners whereby the air received into said manifold passes through said plurality of openings and a portion of each of said runners into said air intake valve inlets of said engine wherein an effective runner length for each of said runners is defined as a distance between a corresponding one of said plurality of openings and corresponding one of said air intake valve inlets; and a runner length adjuster in communication with said tapered drum and operative to rotatably adjust the position of said tapered drum within said housing such that said effective runner length for each of said plurality of runners is variable.