Inertia supercharger for internal combustion engines

Claim 1

An inertia supercharging apparatus for a comparatively low speed internal combustion engine having cylinders within a cylinder head with a plurality of air intake ports formed therein, said supercharging apparatus comprising: a generally barrel shaped surge tank having a substantially cylindrical peripheral surface enclosing an interior volume and having an air intake thereto; and a plurality of spaced apart pipes each having two ends, each pipe having one of said ends open within said surge tank and extending spirally along the inside of said peripheral surface of said surge tank for most of its circumference, said pipes having their other of said ends projecting out of said surge tank through said peripheral surface and connected to respective air intake ports of said cylinder head, said pipes having spaces between them within said surge tank which are unobstructedly open to and form part of said interior volume of said surge tank, wherein said air intake ports are fitted with an air intake manifold consisting of said surge tank and said plurality of pipes, and the diameter of said surge tank is selected so that said pipes will have a length to approximately satisfy the formula: ##EQU4## wherein γ is the frequency of air supplied into the intake manifold, a is the velocity of sound in the supplied air, F pip is an inner sectional area of the surge tank of the air intake manifold, V h is the effective cylinder volume, and 1 is the length of air travel through the air intake manifold including the air intake ports thereof.