New production genuine Hepolite exhaust valves are made to exacting standards. Traditional finish is ideal for use with manganese bronze valve guides.
The exhaust valve is compatible with all BSA A65 models requiring a length of 3.3557″, stem diameter of .310″, and head diameter of 1.410″. The Alpha reference number is V254.
Exhaust valves are critical for proper compression. Once an exhaust valve becomes pitted, cracked, or has been excessively refaced, it may not effectively seal against the valve seat during compression and can lead to poor running and engine damage. Worn valve stems can result in excessive oil consumption.
The valves require lapping-in to make a proper seal at the valve seat. A valve spring compressor is required to install the valve and valve springs. When new valve guides are fitted to the cylinder head, they will require reaming and finishing to achieve the proper valve stem clearance.
Head Diameter: 1.410
Stem Diameter: 0.3100