- Coil Valve Spring Top Cup to fit 1948 onwards OHV models - Model 18, ES2, Model 19 etc
These valve spring parts (see also Item 0672 for the corresponding coil valve spring bottom cup that match with this item) are CNC manufactured by us, dimensions 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.
This is the coil spring top cup fitted to 1948 onwards OHV engines - identifiable from the earlier top cup in that it has a flat top. It was fitted to all Norton single cylinder OHV engines from 1948 onwards to the late 1950's, i.e. those engines with a single casting rocker box. I am not sure why the design changed, but I think resulted in fractionally less pressure on valve springs as the height slightly different to the earlier type (which we also sell - see Item 0673).
However, this top cup is used in conjunction with our coil valve springs and bottom cup (see items 0677 and 0672) which were used on all single cylinder coil spring models - as the bottom cup did not change.
The last two photographs show the later (post 48) OHV engine design which are of the type that this valve spring top cup is intended for