It says it is a universal power brake check valve for most GM/Ford/Chrysler applications. If you can't order online for UK delivery, maybe you go print out the image from the website and go to your local auto parts supplier or the service/parts counter at a GM or Ford dealer to see if they have it, or something equivalent.
I was with Pete Lovell the other day (having oversize guides fitted) and he showed me a reed valve fitted into a beautifully made aluminium alloy assembly such that would fit directly in the oil breather line.
His details are at this link http://petelovelldevelopments.com/home.cfm. He is the chap who does the machine work for Andover Norton and Norvil. He is based in Smethwick, Birmingham, UK. Well worth talking too, as he has so much experience. I ended up talking for an hour or more until my wife dragged me away.
Personally I found a Ducati Paso oil breather valve on eBay for a fiver and fitted it into the line to the oil tank. It has a dual reed and works rather well. If you really wanted to, you could fit one of the rather natty later Ducati valves to the back of the Norton timing chest. They look neat, but the billet variety are expensive and it would require a bit of machining to create a screw thread in the back of the timing case. http://www.yoyodyneti.com/ProductInfo.a ... uctid=LSFT
I just picked up a used anodized billet late Ducati reed valve from a bike breaker for cheap. I was going to get a friend to turn up a hose connection to screw on the end, but I like your idea of mounting it at the back of the timing chest. Then I would just need the right size large metric tap!
I read your post about the paso valve & have been looking for one.
I have spoken to the manufacturer & they tell me they do not have a uk supplier. However they have kindly asked me how many I would like!
I think I will ask for a dozen & offer them to others
all the best Chris
I've just found another alternative. Citroen 2CV's also suffer from increased crankcase pressure causing oil leaks, increased fuel consumption and loss of power. They are also a twin cylinder (albeit flat) with pistons going up and down in unison, akin to most British vertical twins and boxer BMWs. Here's a cure in the UK... http://www.ecas2cvparts.co.uk/valve-cra ... -1401.html