Still produced from the original tooling purchased in 1990 from Jim Whitehouse these Arden alloy 8 port heads were never a straight bolt on conversion. Designed with racing in mind it was developed in 1966/7 to take full advantage of the change to Group 2 racing regulations which allowed more freedom in cylinder head design.

The revolutionary 8-port concept took the racing world by storm and when  Alec Poole took the 1000cc class and championship in 1969 in the Arden car, BMC Special tuning who were developing a cast iron 8 port item decided it 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 as “Eight port head; Part No C-AEG612. These heads were sold by ST Abingdon under part number C-AHT346.

Beware—This head is not a straight bolt on conversion and we recommend you use one of the following companies who have experience.

• Ex ST mechanic and original user of these heads Bill Richards Racing - 01233 624 336 - www.billrichardsracing.com
• Swiftune - 01223 850 843 - www.swiftune.com
• With an electronic injection package as well MBE - 01522545189 - www.mberaceengines.co.uk

The cylinder head is taller than the original A series castings and certain modifications will have to be made depending on how much material is machined off the face of the head, to achieve the compression ratios required.

1. 4 longer studs 51K282 must be used on the inlet side
2. If the rear block studs are not long enough 51K281 can be used
3. Standard push rods will not be long enough so the following alternatives are usually used
   

   1. Machine rocker posts, original sintered are shorter than the steel type used on Hi-lift rockers. Do not machine posts on roller type alloy rockers as they will foul valve top caps.
   2. Use longer adjustable screws C-AEA692 (except full roller rockers)           
   3. If possible get longer carbon fibre push rods made approx 0.220” (5.60mm) longer or modified standard type from Bill Richards Racing 01233624336
   4. Old 1500cc Leyland Rover B series push rods 11G241 are slightly longer but require machining to fit through head
   5. Ford 105E Anglia cam followers/push rods and modify.

4. Cooper S Con rods and crankshaft should be used with 1.625” big end

Journal size---number 2 and 4 con rods will need modifying as the top edge of the bolts may foul the special camshaft, which has a non standard valve sequence. On Keith Dodd,s road use 8 port car the standard A-Plus 1.75 con rods and crank were used by modyfing the con rods and bolts on one side only.Machining 2mm from bolt head area and recut radius-modify top of bolt. See or apply for diagram. The nominal 16cc combustion chambers are left in a basic shape with enough metal for those with the latest advanced ideas of shape to apply them and create the correct compression ratio for the desired use. Valve and seat material specification allows use of unleaded petrol.

Thoroughly clean the cylinder head before final assembly. Check that the small circlip is in the correct position in the valve guide at a point where the guide protrudes through the cylinder head beneath the valve seat. Place valve spring seats over the guide. Fit valves using anti scuffing paste, fit rubber valve guide seals.

The head should be fitted using head gasket C-AHT188 or if you prefer late black composite type head gaskets use TAM1521 (but not GUG702560HG)

If the heater is not being used, fit blanking plate 2A180 to the heater valve take off at the rear of the head. Use standard water elbow and gasket.

Check rockers are central over valves (forged rockers may require machining) and ensure all rockers do not foul the top caps.

Check that all valve train is functioning correctly and valves not hitting pistons on modified blocks.Most people machine the pistons to get desired compression ratio

If the cylinder block being used has undergone machining to bring the piston to within 0.10” (0.254mm) of the block face, machining the piston crown is always necessary.

A special exhaust manifold C-AHT343 will be required.

10mm spark plugs are required for this head-C8E for road use and C9E for race.