This high quality spun aluminum velocity stack is designed specifically to fit the 1.75 inch SU H6 / HS6 and Zenith-Stromberg HIF44 carburetors on many Triumph and MG engines. It will also fit the Hitachi clone of the SU H6 / HS6, which is found on some Datsun engines.
This part is carefully crafted to the original Kas Kastner pattern. Dyno tests have shown an amazing increase of 4-6 horsepower on four cylinder Triumph engines, and up to an 8 horsepower increase on the Triumph GT-6. The overall height including mounting flange is approximately 2.5" (+/- 0.25"), and the bell has a maximum OD of 5.2" (+/- 0.1"). Throat ID at mounting flange 1.625". Sold individually.
How does a 1 5/8" horn fit a 1 3/4" carb? Carburetor size nomenclature refers to the diameter of the throttle plate, not to the size of the inlet opening. H6/HS6 and HIF44 carburetors have a 1.75" (44mm) diameter throttle butterfly. If you remove one of these carbs from the manifold, you will measure a 1.75" diameter outlet on the back of the carb. The opening on the inlet (air filter) side on all of these 1.75" carbs is 1.625" diameter.
