This is a complete rockerbox cheesehead screw set for 1938 to 1947 type OHV Norton single cylinder models - i.e. Model 18, ES2, Mod 19, Mod 50. It consists of the cheeseheads that surround the rockerbox cover, red fibre washers for these, the extra long tappet cover cheesehead screws (fitted only to this Norton single model) and stainless washers to go with these tappet screws - all of these being CNC bar-turned in stainless steel to the original period Norton dimensions and head pattern.
As you can see from the photographs, this cheeseheaad set is shown fitted in the photographs to a 1938 OHV Model 18 engine, which is not the most common model of Norton single, but used a number of semi long cheesehead screws not found on other models - which I think gave that rockerbox a purposeful attractive look.
Also, the pressed steel tappet cover for this model - although looking identical to the later (and more common) 1948-56 type OHV model, had different cheehead screw hole spacing than the later tappet cover - and used extra long cheesehead screws, not fitted to any other model
This set consists for following:
7 x Rockerbox semi-long cheesehead screws
2 x Extra long tappet cover cheesehead screws (also available seperately - see Item 1002)
2 x Stainless steel tappet cover washers
8 x High quality red fibre washers to fit behind cheesehead screws (7 screws + 1 spare washer1)
All screws are bar turned stainless steel which we CNC manufacture in-house. For every screw, dimensions are faithfully replicated from original screws. We also ensure the cheesehead head pattern is faithfully replicated from the original Norton screw, and these are actually slightly wider diameter heads than most commerically available 1/4" diameter cheesehead and allen screws.
The set also includes 8 high quality red fibre washers (we always include an extra fibre washer - in case you lose one under the bench!).
Sorry, not as cheap as some of the mass produced type available – but these are CNC turned from stainless steel bar with milled head slots to the original dimensions in small batches.
Final assembly points:
All engine timing covers and rockerbox covers of this period were originally fitted with red fibre washers behind them, which often get omitted. We recommend always fitting these and supply a high quality example (which are much better quality than most commercially available).
This type of OHV rockerbox tappet cover looked exactly the same as the later 48-55 OHV engine, but actually had different spacing of the holes to the later engine design - and very long cheesehead screws (which as far as we know were longer than any other Norton cheeseheads used on any other models). We also sell the tappet cover gasket for this model (Item 0918) and are also looking at getting the unusual pushrod rubber seal unique to this rockerbox manufactured - please email for details.
We also sell the engine crankcase and timing cover cheesehead set for the same model - Item 1000, both together will transform the look of your Model 18/ES2 restoration project