Big Valve cylinder head for 998cc engine

Approx 23.5cc combustion chambers for use with dished pistons. This specification of cylinder head is the only modified version for the small-bore based engines Mini Mania supply as it is judged to be the only one worth up-grading to. Based on used core castings, it is modified to current road-sports style to maximize road-sports and track day/weekend-warrior performance when used with road-sports and super-sports camshaft specifications. That means optimized BHP and torque out-put through port shape and dimensions and valve throat shapes developed on airflow bench and dyno/rolling roads to work with the aforementioned camshaft types, along with suitable compression ratios given modern lead-free fuel specifications. High quality Serdi lead-free exhaust seat inserts are fitted. Latest specification manganese-bronze valve guides are used along with the latest specification plasma-nitrided EN214N stainless steel (30.93mm inlet and 26.5mm exhaust) and 180lb (nominal at maximum valve lift) double valve springs to give a cylinder head capable of withstanding a maximum continual peak rpm limit of 7,500rpm and 0.475" actual valve lift. Suitable for auto-testing, hill-climbs and track day use. Combustion chambers are set at an average 23.5cc for dished pistons. 9-stud fitting as standard. This head has the heater take-off port open and a by-pass hose adapter fitted. Both or either can be blanked off as needed.