Cylinder Head Assy, complete, stage 2, unleaded, aluminium

Stage II cylinder head – uprated road - New valves, guides, springs, polished and ported to stage II.
Modifications include gas flowed ports and reshaped combustion chambers. New standard diameter valves are reshaped and fitted with new guides and uprated spring valves.

Our range of gas flowed heads are available to suit all needs. All heads are supplied with stainless valves, bronze-alloy valve guides and valve seats suitable for unleaded petrol unless requested otherwise. These cylinder head specifications are based on a 9.5:1 compression ratio on an 87mm engine. Please advise us of the engine capacity and any planned changes when ordering.

These have been manufactured as close as possible to the original TR4A specification , with the exception of a few upgrades, notably, the webs between the spark plugs have been improved and the flange thickness has been increased to give added strength especially if it is skimmed for a higher compression ratio. The inlet valve shroud(the overhang directly below the inlet valve) has been removed, which is what you have to do when skimming a TR4A head, this may look a little unusual when fitting a head gasket against it but it works absolutely fine.