Valve guides

[k. rogers]

I'm in the process of reassembling the engine for the Kingfisher at present and something has come to light. It was stated in the specification from 1931 that the inlet valve guides are 'positively lubricated' via a small hole near the guide collar. However, after careful examination of mine there are no such holes. I assume they are original for the crankcase and they were sleeved because of wear by the engineer who did the work. Obviously, the sleeves would make any lubrication holes ineffective anyway, but how important is it to have this form of lubrication which Jowetts continued up to and including the Bradford? Incidentally, the valves are all new supplied by club spares.

[k. rogers]

Further to this post, I can now answer my own question! I went to Geoff Wills' yesterday with the cylinders to decide what to do about the valve guides. It's amazing what you discover with someone elses knowledge and a workshop flooded with natural light. Firstly, it was apparent on examination that the guides had been sleeved with just copper would you believe? Imagine how long they would have lasted. So, it was decided that they had to be removed and some replacements sourced and refitted at a later date. The inlet guides came out relatively easily with Geoff's specially made drift tool (oh, for a lathe and the expertise to use it!) but the exhausts were swines and only came out after drilling out the bulk of the guides first. What we found when they were removed was that as if it wasn't bad enough that they had been sleeved with copper it was also paper thin!
Once the guides were removed the small lubrication holes on the inlets were then obvious, drilled in a notch cut out of the rim of the collar but now void because of the sleeving process. Interestingly, the postion of these holes changed on the later guides to the smaller diameter section of the guide. We speculated as to why this was changed and thought that it was possible that in its first postion the hole would have been continually submerged in oil so let a bit too much through. The later method was kept right up to the Bradfords.
Now to source replacements; club spares?

[k. rogers]

Just an update. Have obtained new guides from club spares for fractionally more than the original cost of having the old ones sleeved - there's a lesson! These are apparently the very last design of guide, presumably Bradford, with the exhausts having one drilling and the inlets having two for extra lubrication.