This is an exact reproduction of the valve guide bottom collar that held hairpin valve springs on the Norton SOHC International model, as well as original SOHC Manx heads. These are based on an original International valve collar - even including the patent number, but we have them cast in stainlesss steel so they do not rust, and are CNC machined.
Price is Each.
Update May 2023: New batch now in stock (please note - since we manufactured these last, in 2015, the price of stainless steel castings and CNC machining has risen very considerably. Therefore, hope you will understand why this hard to find item is not cheap)
This item is cast from a Lost Wax casting, which we had patterns made for - which provides a higher quality finish than normal sand cast type, and even includes the correct cast in Patent numbers. It is CNC machined to a high standard of finish. Note: we also make our exhaust valve guides in the same style as the inlet guides, so this same collar can be used in conjunction with the Exhaust guide, rather than the original single piece exhaust cast bronze guide\collar (which is no longer commercially available) - see the Exhaust Guide description for more information.
Fitting Information: These collars are a close fit over our valve guides (which helps heat dissipation from the guide - which I think may be why the exhaust guides/spring holders were originally made as a single casting), and are easily tapped on, after fitting the valve guides.
The machined collars on their underside have a countersink that fits neatly over the lip of the valve guide .. . but most importantly they also have an additional hole on either side - which corresponds to a peg which should be in place on all SOHC original heads that employed hairpin valve springs. This peg was to ensure that the hairpin valve spring holder did not rotate, and that the springs were kept in the correct position. If you look closely you will see the holes on the underneath of our collars are slightly different sizes - these are to fit the two most common size of pegs I have seen on original heads. I have found the larger of the two holes should correspond to the most commonly fitted peg - but either hole can be used, providing they fit the original of your head (normally heads only have the peg on one side of the valve guide). Note: You may find your head has had the original peg replaced with a bigger version over the years - if so - it is a simple task to open up one of the holes of our collar, to fit your peg.
Note: valve guides and hairpin valve springs are sold seperately, this listing is for the collar casting only
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