Subaru KX21 Go Kart Engine Cylinder Heads
many hours of testing have been spent on the flow bench, we tested the stock kx21 Subaru carburettor, straight intake manifolds, curved intake manifolds & round slide carbs. We were surprised at the flow at low valve lift. The heads maximum flow is just before coil bind occurs there became a point where opening the valve more didnt increase flow. Some more development is required with a longer valve to see if the head will flow more with more valve lift.
The curved manifold offers a step up in performance over the standard carb to head set up & also repositions the carb away from the rear tyre.The shape of the intake runner with its high port roof & low raked floor has a very wide low angle short turn for the air flow to fill the cylinder.
The angle of the valve on the Subaru cylinder head is definitely an advantage in performance.
WE WILL SOON HAVE MODIFIED PERFORMANCE EXCHANGE CYLINDER HEADS
In its standard form the improved components need for your EX21 engine, KX21 cylinder head including valve train components, sports camshaft & KX21 carburetor