Dear all,
I have just spent a happy afternoon stripping down my late engined Navigator cylinder heads to refurbish them. I discovered that the valve guides are very different from my memory of Navigators and Jubilees I worked on back in the day. The top of the valve guide has a step with a cone shaped end shown in the attached photo. The valve guides I remember are same shape as the ones sold by the NOC. Is my memory correct or are the ones in my bike an original Norton design or ssid they change the deisgn on the later engines? Having discovered my mystery pistons I am wondering if this is another variation?!!!
Cheers Nick
valve guides
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Valve guides
Hi Nick,
My 1964 Electra had steel guides with oil wiping lips as you describe. This was at 18000 miles. When I bought the bike in 2004 the NOC stocked 3 styles of l/w valve guide, including the iron with lip. By the time I got round to replacing there was only the bronze without lip.
I wrote up the replacement experience in Roadholder.
New valves are much easier to fit if your existing valve stems are worn.
Peter
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Valve guides
I've attached two pictures showing how I have modified the valve guides for my Navigator.
I have "knife edged" the top end to wipe off excess oil from the valve stems. There is no need to machine the knife edge to a sharp edge, a 0.010"/0.25mm land will be okay and somewhat less fragile then a sharp edge.
At the other end I have radiused the corner,well worth doing to reduce heat pick-up, particularly on the exhaust side.
John
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Valve Guides
Hi Nick,
You have the later valve guides - the 'cone' shape you refer to is an oil scraper - to cut down the amount of oil sucked down the valves on later engines with the 6-start oil pump. When blatting along, there head is probably awash with oil, and this was an attempt to keep it up there.
Its the Norton Lightweight answer to valve-stem oil seals....:)
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The guides fitted to my 1963 Navigator were identical to the replacements supplied by the NOC if that helps, Looking at your photo I am sure fitting new NOC guides will not be an issue so long as the length of protrusion in to the rocker-box and engine are the same.