Leading A-Series engine specialist since 1981
Flow bench designed and tested for maximum airflow on our Superflow 110 flowbench, this head uses the very latest development in port design with high roof inlet ports and negative radius valve guide boss removal.
The combustion chamber is modified with full radius side walls and double radius valve seats, all cut to race tolerances to help maintain equal combustion chamber volume. The valve seats are blended into both chamber and port to maximise airflow.
The head comes with 31mm exhaust valves with offset centre line positioning, enabling us to fit extra large 38mm inlet valves. These give the extra airflow required for large-capacity race engines.
The valves are our own bespoke design produced from a one-piece plasma nitride forging with a lightweight 6mm stem and three-angle valve seat, probably the best valve available for the A-Series engine.
Before our own 6mm high-flow bronze valve guides are fitted, the valve spring platforms are machined to maintain equal fitted length valve springs.
Finally the head is carefully assembled with our lightweight titanium valve caps, dual rate valve springs and bespoke 6mm collets. Supplied with the cylinder head are our button lash caps, which locate inside the titanium cap for the roller rockers to run upon, giving a greater wipe area for high-lift camshaft applications.
Options which will be confirmed via email after initial order;
Please note, these cylinder heads are machined to order - once you have purchased this product a member of our sales team will contact you to finalise the specification and advise delivery.
We aim to deliver with 20 working days from the initial order, however during the race season this can vary with demand. Please contact us for the most accurate lead times.
Please select the 'exchange' option above if you intend to supply a serviceable 12G940 cylinder head casting to be modified. If you do not have a cylinder head to send in, there is now a £350 surcharge applied to encourage a continuous supply of head castings.
For race heads we insist on using castings without valve seat inserts, so the exchange unit must be of this type. Please contact us for further information.