SOHC Valve Spring Top Cup and Collet - Late Manx Valve (5/16") - Pair

CNC Machined top cup and 5/16" valve stem (normally early Manx DOHC engines or late Manx SOHC engines) collet. 

Note: These top cups are sold complete with a matching set of collets (pair) to fit a 5/16 Manx Inlet or Exhaust valve.

Regarding 5/16" stem diameter valves:  Most SOHC International (road going) and earlier SOHC racing engines were fitted with 11/32" (inlet) and 3/8" (exhaust) stem diameter valves.  However, some later SOHC racing (M30/M40 and Manx) engines, as well as most DOHC Manx engines were fitted with 5/16" stem valves, for both inlet and exhaust valves.  We do sell a small selection of 5/16" stem valves, as well as the 5/16" collets to fit those valves.  And here are listed the 5/16" collet, complete with top cup.  If your (Manx) engine is fitted with 5/16" valves then two of these will be required per head.

Although these are made using the original taper, I have found many pattern collets have slight variations and do not seat properly. Therefore these top cups have been machined with exactly the same taper as the collets and are sold as a matching pair.

These top cups/valve collets fit inside the Top Cup Plate (our Item 0284) on SOHC (and DOHC engines), to retain the hairpin valve springs.  Top Cup Plates are sold seperately