High quality exhaust valves manufactured by G & S Valves - Following Head Sizes available (check your original) : 1.735" or 1.750". Standard Model 30\40 stem diameter : 3/8" - Stem length: either 4.565" or 4.590".

These valves already have the collet groove machined and are ready to fit. Note: Norton cammy valves were made in a variety of lengths over the years, however, this length - 4.590" is one of the most commonly used. 4.565" is one of the shorter lengths available. If you have an original then measure that. If you are unsure please email me.

High quality exhaust valves manufactured by G & S Valves - Following Head Sizes available (check your original) : 1.735" or 1.750". Standard Model 30\40

stem diameter : 3/8" - Stem length: 4.635" or 4.650" - both these being a common longer length valve (see also 0037B for slightly shorter exhaust valves of the same head diameter).  Note - only 15 thou difference between length of stem of these valve variants - so if corresponding inlet valve length is not available, but other size is - 15 thou is easily adjusted for with the rocker 3 part adjuster.

These valves already have the collet groove machined and are ready to fit. Note: Norton cammy valves were made in a variety of lengths over the years, although not as commonly used as the shorter lengths, both these lengths - 4.635" and 4.650" were sometimes used, particularly with larger inlet valve heads. If you have an original then measure that. If you are unsure please email me.

- High quality inlet valves manufactured by G & S Valves - Following Head Sizes available (check your original) : 1.635" - standard Model 30/40 stem diameter : 11/32" - Stem length: 4.875".

Left blank at end, so these can be cut to the same length as your original, and then the collet groove machined afterwards. This is the best way to ensure that you will have a valve the correct length for your cambox and spacing between cambox and head, particularly important if you are replacing a valve with a more obscure length. This type requires you undertake the final cutting to length yourself.

The last picture for this listing gives the collet groove dimensions - as are performed by G&S on the 'sized' valves, so you can machine these valves to the correct dimensions.

If you wish us to cut the valve to length and machine the collet groove, please email seperately with order - expect £12 charge per valve, and turnaround time of at least 3 weeks.

- High quality inlet valves manufactured by G & S Valves - Following Head Sizes available (check your original) : 1.635" or 1.655". Standard Model 30\40 stem diameter : 11/32" - Stem length: 4.590".

These valves already have the collet groove machined and are ready to fit. Note: Norton cammy valves were made in a variety of lengths over the years, however, this length - 4.590" is one of the most commonly used. If you have an original then measure that. If you are unsure please email me.

High quality exhaust valves manufactured by G & S Valves - Head Size : 1.635" or 1.655", with standard Model 30/40 stem diameter : 3/8" and blank stem.

This is blank stem type, where customer cuts length and groove themselves.  1.635"/1.655" head diameter are the most common sizes for 350cc Model 40 International exhaust valves. Price is each.  This is a variable listing, see listing detail for indvidual stock availability

Left blank at end, so these can be cut to the same length as your original, and then the collet groove machined afterwards. This is the best way to ensure that you will have a valve the correct length for your cambox and spacing between cambox and head, particularly important if you are replacing a valve with a more obscure length.

This type requires you undertake the final cutting to length yourself.

The last picture for this listing gives the collet groove dimensions - as are performed by G&S on the 'sized' valves, so you can machine these valves to the correct dimensions.

If you wish us to cut the valve to length and machine the collet groove, please email seperately with order - expect £12 charge per valve, and turnaround time of at least 3 weeks.

- High quality exhaust valves manufactured by G & S Valves - Following Head Sizes available (check your original) : 1.635" or 1.655". Standard Model 30\40 stem diameter : 3/8" - Valve Stem length: 4.590".

These valves already have the collet groove machined and are ready to fit. Note: Norton cammy valves were made in a variety of lengths over the years, however, this length - 4.590" is one of the most commonly used. If you have an original then measure that. If you are unsure please email me.

Price is Each

CNC Machined top cup and 11/32" (SOHC inlet valve), to take tapered collets, to fit all SOHC engines.

Note: These top cups are sold complete with a matching set of collets (pair) to fit a 11/32" inlet valve.

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

CNC Machined top cup and 3/8" (SOHC Exhaust) collets, to fit all SOHC engines.

Note: These top cups are sold complete with a matching set of collets (pair) to fit a 3/8" Exhaust valve.

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

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

CNC Machined top cup plate, with distinctive ears, which retain the hairpin valve springs on all SOHC engines using hairpin valve springs (and also pre-shortstroke DOHC engines).

These valve spring retainers fit all top cup plates (sold seperately) and are milled from solid. Unlike the originals (which were made from flimsy pressed steel and wear badly - with obvious consequences), these items are machined from solid EN24T and are extremely tough and hardwearing.

These are not a cheap item - as they are milled from solid and from a hard wearing material (high tool wear when machining), but are much stronger than the original items and fit both Inter and Manx style hairpin valve springs and our top cups very nicely - so well worth replacing your originals if you have any doubts about wear (check originals underneath, where the eye of the hairpin valve spring contacts the ear of the plate)