CNC-machined aluminium intake manifold spacer from NARAKU. The Naraku Jet Flow spacer is designed to optimize flow in NARAKU 51mm cylinder heads. The conical bore of the spacer allows unrestricted flow from 24mm manifolds to 21mm inlet ports on the 51mm cylinder head (present in 51mm and 52.4 mm NARAKU cylinder kits). The resulting venture-effect means fresh gas is forced in and improves the volume in the combustion chamber. This results in an increase in torque With appropriate adaptation work to the original cylinder head or intake manifold, the spacer can be used with a stock setup or tuning levels below 90cc kits! Using a 24mm carburettor is ideal, but not necessary. When fitting, ensure a flush fit between the spacer to the cylinder head. The spacer can be mounted 180 ° accidentally reversed. In this case, it covers the inlet channel .