Andy my handsome, I need a little more than Andy B to find your address in my admin address book, so if you'd like to PM me as my e-mail is inside front cover of MPH.
Bananaman.
Bananaman.
Thanks Peter, any chance of a picture of both types of valve? Pretty please?Well actually no, Marcus, it's not my knowledge; I was merely quoting the findings and knowledge of the late great Bob Stafford.
But the Series 'A' spring collet issue doesn't end here. I have several crusty old used (original?) valves and some old stock new ones too. All have the correct "squared" 90 degree interface between the large and small stem diameters to take the correct "squared top" collets. Great.
But I also have some new Series 'A' valves which I purchased in the UK about 2 to 3 years ago. These are most probably manufactured by the G & S valve company. However, whoever got them made(?), forgot to specify the need for the stem interface to be square; what they actually have is a small taper for about 1/32". So, if you intend to use standard 'A' collets on a standard set-up (and why wouldn't you?), each valve needs that tiny taper machining square on a lathe with a very sharp tool.
Anyone in the process of, or about to start, head-building - would be wise to check what they have in respect of collets and valves.
Peter B
Excellent detail Peter thank you, I also have approx 12 used valves mostly according to your research,are old stock, fortunately I have at least one good pair that I have had refinished. Thank you for your knowledge and time.Andy,
I've got 6 crusty old used valves, decades old - all the same (ie square stem interface).
I've got 4 "new" valves - 2 square and 2 tapered.
Not sure these photos will do them justice, but here's a sample, numbering from the left:-
1 & 2 = crusty, decades-old valves (square).
3 = new valve, (square), bought about 2005/6 during Colin Jenner's custodianship of Conways.
4 = new valve, (taper), bought around 2016/17 (can't be sure who from).
As an aside, from the marks on the old valves, I would estimate the split collets used were 1/4" high.
Peter B
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I will enjoy buying you a beer if I get the pleasure of your company Marcus, look me up if in Melbourne. I will be travelling to Liverpool and Portsmouth in March for a reunion of my old RN colleagues and hope to call in at the new club rooms on my travels. Thanks a bunch.Here you are Andy,
Back row 2 NOS inlets (50 + years that I've had them) 2 used v/v's
front row two used and one new in last twenty years. with mandrel to machine collets
note : all v/v's have 5/16" dia upper stem, all my inlets have 11/32" lower stem dia and exhaust's have 3/8" dia stems
None of them have a sharp 90 degree at the change of diameter
assorted collets with four shiny new pair from VOCSC and Andy's pair in an envelope ready to be posted.
Now you know what rubbish I hang onto.
bananaman.
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