The original Arden 8 port head tooling was purchased from Jim Whitehouse in 1990, sadly genius Jim died in 2008 aged 89.

Designed with racing in mind it was developed in 1966/7 to take full advantage of the change in Group 2 racing regulations that allowed more freedom in cylinder head design. This revolutionary 8-port concept took the world by storm when Alex Poole took the 1000cc class and British Saloon car championship series outright in 1969 in an Arden Equipe team 970cc Cooper S with the 8 port head and Tecalemit fuel injection.

BMC Special Tuning who were developing the cast iron 8 port head C-AEG612 decided alloy was the way to go and dropped their version and commissioned 200 Arden 8 port alloy heads which were fully homologated under FIA regulation amendments 21/15V/GRI and sold as C-AHT346.

Now well over 40 years old the wooden casting boxes are still being used but only one person knew the art of feeding alloy into the water gallery jackets to ensure there were no flaws causing leaks, so along with the internals all needing refurbishment Mini Spares decided to revamp the original tooling with new internal state of the art casting boxes to produce a high precision casting for road and race, but bring it up to date enabling a few needed changes, namely a larger 21cc combustion chamber which facilitates sensible compression ratios on large bore engines plus valve guides with a step to retain the valve spring platform as per all modern day race heads.

After extensive gas flowing tests it was also found that the exhaust ports chambers were too large and making them smaller to work with the 30.5 mm valve increased gas flow. It was also found that increasing the inlet valve to 37mm with a new inlet core provided further substantial increases in power so now there are 2 versions, original homologated size 35.6 mm and the new 37mm inlet size and will handle cam lifts up to .500".

All heads are now numbered with their specifications and valves sizes recorded In the event of spares being required as these heads are now slightly different. All heads are supplied fully assembled with new stud kits for block to head and head, gaskets for inlet and exhaust manifold plus longer push rods to ensure the rocker geometry remains correct.

Fully assembled roller rocker sets are also available to further increase performance and ensure correct rocker geometry. A special exhaust manifold and camshaft with transposed lobes on No2 and No4 cylinders are also required. Original "S" rods/bolts will need modifying to stop fouling or a special modified set is available from Mini Spares.

3 A Plus type camshafts are available and with Fuel injection using the 37mm Inlet valve the   following figures were obtained by MBE Engineering.

• C-AEG312 Road cam produced 120BHP and 107 lb/ft maximum.
• C-AEG311 Rally cam 140 BHP and 109lb/ft torque maximum
• C-AEG310 Race cam 145 BHP with 113lb/ft torque maximum.

Available as :-

Gains - Much more power and especially torque compared to 5 or 7 port heads.
When comparing costs of doing engine rebuilds it is only slightly more expensive in extra machining works and cost of an 8 port exhaust manifold as one usually expects to be changing the camshaft and carburation or fuel injection anyway.