1.c Norton SOHC Head and Barrel

SOHC (and Early DOHC) Valve Section

The following listings detail a selection of inlet and exhaust valve sizes for SOHC engines.

Read this listing for some general information on Norton SOHC valves

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- High quality inlet valves manufactured by G & S Valves - Following Head Sizes available (check your original) : 1.750" or 1.790" diameter. Standard Model 30/40 stem diameter : 11/32".  This listing is for a valve with a blank stem (no groove machined) so you can cut it to length and machine the collet groove yourself, if the valve you are replacing is not one of our standard lengths. Variable Listing - See detail listing to check stock availability for each variant 

- High quality inlet valves manufactured by G & S Valves - Following Head Sizes available (check your original) : 1.735", 1.750" or 1.790" diameter. Standard Model 30\40 stem diameter : 11/32" - Stem length: 4.590" or 4.625". Variable Listing - See detail listing to check stock availability for each variant.  New interim batch - April 2024

- High quality inlet valves manufactured by G & S Valves - This valve is in a larger head size - 1.825". It was sometimes fitted to later International's and SOHC Manx's (but can also be fitted to earlier engines if req'd) - standard Model 30\40 stem diameter : 11/32" - Stem length: 4.590". Price is Each. Variable Listing - See detail listing to check stock availability for each variant 

- High quality inlet valves manufactured by G & S Valves - This valve is in a larger head size - 1.825". It was sometimes fitted to later International's and SOHC Manx's (but can also be fitted to earlier engines if req'd) - standard Model 30\40 stem diameter : 11/32" - Stem length: 4.650". Price is Each. Variable Listing - See detail listing to check stock availability for each variant 

- High quality inlet valves manufactured by G & S Valves - This valve is in a larger head size - 1.855". Probably the largest diameter head inlet valve fitted to SOHC Norton engines, this head would normally only be fitted to racing engines (I think I have one of these fitted in one of my racing methanol heads. Standard Model 30\40 stem diameter : 11/32" - Stem length: 4.650". Variable Listing - See detail listing to check stock availability for each variant 

- High quality inlet (or Exhaust) valves manufactured by G & S Valves for later SOHC heads fitted with 5/16" stem valves. - Following Head Sizes available (check your original) : 1.750 and 1.790". Valve stem diameter : 5/16" valves were sometime fitted to late SOHC Manx engines and early DOHC engines. Variable Listing - See detail listing to check stock availability for each variant 

- High quality SOHC valves manufactured by G & S Valves - This listing being for those fitted to roadgoing Featherbed (500c)) International models. Inlet valve with 1.750" diameter head or exhaust valve with 1.735" diam Dimensions: both valve types being slightly longer than earlier Inter engines - with a valve stem of 4.750" length (sized for collet).  Price is each. Variable Listing - See detail listing to check stock availability for each variant   

- 'New Old Stock' (i.e. not our modern G&S manufacture):  11/32" stem Inlet valve - with the most common original Model 30 International head diameter - 1.735" and with a length of 4.600" sized with collet groove.  New Old Stock - may be original Norton SOHC Inlet valves.  See detail listing for more information.  Price is each.

- High quality exhaust valves manufactured by G & S Valves. - Following Head Sizes available (check your original) : 1.735" and 1.750". Standard Model 30/40 stem diameter : 3/8". Stem length: 4.875". Variable Listing - See detail listing to check stock availability for each variant (New batch: April 2024)