Part #: 800-1426
New round top SU carburetor kit for Datsun 240Z. New design SU round top carburetors that are a direct bolt on to 1970-72 Datsun 240Z engines. Includes a pair of 44mm made in UK, SU carbs with all hardware needed for bolting up to a 240Z manifold. Includes 2 carburetors, insulators and gaskets, oil, throttle shafts and correct collars. We were able to bolt up this set on a 72' 240Z in under 2 hours with no mods needed. * The inlet bolt pattern of these carburetors are slightly different than the original Datsun SU's so that these will not directly bolt up to the stock air cleaner. K&N air filters available. * Your existing choke cable may need to be modified. *See 800-1427 for K&N filters to fit these carbs.
Advantages of the modern SU carburetor:
-Improved materials are now able to accommodate ethanol mixed gasoline. -Adjustable metering allows a selection of fuel types, either for highway use or racetrack. -Internal float system is more stable with cornering forces. -Bi-metallic thermally compensating mixture adjustment adjusts for temperature changes. -Improved manufacturing technology and materials for more consistency. - The cold start on the HIF has the advantage of being an enclosed enrichment valve and not repositioning the jet as on the HS carb. This should lead to fueling being more consistent over the life of the carb between servicing
Vaporlock Improvement: The original design used external floats with flexible tubes running to the metering needle and seat, these doubled as a 'choke' used for cold starts. These parts are directly above the exhaust manifold on the L6 design engine used in the 240/260/280 Z cars, it gets very hot in this location, and the un-shielded floats do little to protect the fuel supply. The HIF44, the basis for the ABF973, encases the float and replaces the moving seat with an internal enrichment valve, thus providing additional metal mass around the hottest areas. Additionally, we use dual-pass-through fuel feeds that help dissipate hot spots in the fuel supply, and help prevent fuel starvation from cornering and acceleration. Finally, the new design uses a temperature compensation valve that increases flow at higher temps as the fuel becomes less dense. The new design works better than the old design that was designed for the cool British climate.