- Coil Valve Spring Bottom Cup to fit early SOHC (coil spring variant) Model 30/40 International, CS1/CJ as well as all Norton OHV models.
These valve spring parts (see also Item 0673 and 0674 for the two different types of corresponding coil valve spring top cups that match with this item) are CNC manufactured by us, copied from original patterns. They are steel as per originals, then they are chemically blackened to protect from rust. They are also stored in light Duck oil.
Coil springs were used on all early Norton SOHC Carrol engines - Model 30/40 and CS1/CJ until 1935. Works engines first used hairpin valve springs in 1934 and Model 30/40 International engines switched to hairpin valve spings in 1935, but CS1/CJ engines continued with these coil springs . They were also fitted to OHV engines (Model 18,50,55, 19, ES2) all the way through the 1940's and through the different later design of 1950's OHV engines until the late 1950's. This bottom spring cup plate is of the correct type for all these coil spring engines
Note see item 0674 for corresponding top cup for later 1948 onwards OHV valve engines, or item 0673 for the earlier top cup plate fitted to all coil spring SOHC engines and pre-48 OHV engines.
The corresponding valve springs for these cup plates are Item 0677. Note however, collets for SOHC and OHV engines are different, of which we sell all the different types
You will see in the corresponding photographs I have shown a picture of the bottom cup sat on top of an original OHV cast iron valve guide. The photograph following that one shows our (freshly blackened) item next to the original item for compariison.
I have also shown a line diagram of the original coil spring SOHC engine - if fitting these to an SOHC engine you need to check it is the correct coil spring cylinder head - not a later Inter hairpin head (normally identifiable because hairpin heads have the seat where the spring holder sits milled flat). To help with this identification - I have attached a picture from the 1937 Norton Spare Parts catalog which shows a hairpin International cylinder head (8771) next to a coil spring CS1 cylinder head (8772) so you can see the detail differences