MED STEEL CONRODS - STD LENGTH - 18MM PIN - 'S' 1.625 ENDS
( £741.67 EXC VAT )
The original eight-port cylinder head - this is the race version with larger inlet valves and special seats available. Ports and combustion chambers are CNC machined and ready to use. Combustion chamber is approximately 21cc.
Heads are supplied fully assembled with titanium top caps and race valves springs, using larger 1.464-inch inlet valves and 1.216-inch exhaust valves. This will handle valve lifts up to 0.500-inch
Also included in this kit is a set of correct length MED solid push rods, complete head stud set and a competition manifold gasket.
Steel conrods will be needed for clearance due to cam lobe configuration.
The Arden eight-port offers the ultimate performance upgrade for the A-Series engine, converting from the siamese inlet port design of the original five-port head to a crossflow setup. Although excellent gas flow and overall power can be achieved from a full-race five-port, the upgrade to a crossflow design removes the scavenging problems associated with shared inlet ports.
This allows for a more consistant fuel/air mixture across all four cylinders, while straighter inlet tracts, large ports and race valves all help to unleash more power. Using aluminium also reduces overall weight and greatly improves heat dissipation compared with a regular cast iron cylinder head.
We keep two different lengths of inlet manifold for mounting 45DCOE carburettors up front, although fitment within a regular round nose Mini is made far easier with an upgrade to fuel injection. Not only are the throttle bodies a more compact setup, but increased performance across the entire RPM range will also be achieved, making it the most effective option for both road and competition. The kit uses a DTA ECU and professionally made wiring loom.
The Special Tuning Arden eight-port head was originally developed in the late 1960s for use on 970 Cooper S engines, but the latest design has been tweaked for use on 1275s, with larger 21cc chambers. With a carefully built bottom end and fuel injection, maximum outputs of well over 150bhp are possible.
Please note that the head is not a direct bolt-on upgrade over the original five-port head, requiring a different type of camshaft, rockers, steel con rods, longer pushrods and different manifolds. Therefore the engine build should be based around using the Arden head, for which we keep all of the parts in stock, including a range of Piper camshafts.
For full-race engines we would highly recommend the use of a steel crankshaft package, four-bolt steel main caps and an MED dog-engagement gear set.