Learning as I go, I have discovered that camshaft timing side bushes are flanged (part No 22925) and drive side bushes are non flanged (part No 20772A). I have been sent two non flanged bushes by the NOC spares team that are annotated on the accompanying paperwork as part no 22925, timing side only, which I now believe to be wrong. Not realising that the opposing bushes were different, I then asked for two more 22925 bushes from a well known Norton parts supplier (WKNPS), as the NOC team had sent me their last two bushes. Luckily, the WKNPS sent me one 22925 and one 20772A, which set my alarm bells ringing. Just to confuse the issue further, the Jubilee spare parts list from 1959, lists the timing side flanged bush as Part No 20771A.
Assuming that my deductions are correct, I'm planning to order two more opposing bushes from the WKNPS and ask for my money back from the NOC spares Dept. I'd just like some kindly Lightweight owner to corroborate my findings before I go off the deep end without my little blow up arm bands on. After all, £47.99 could have been a 22925, non flanged, drive side disaster.
Happy Easter
Kev
Camshaft bushes.
- Log in to post comments
Much appreciation.
Thanks for that Peter. I can go round to the shallow end and put my arm bands away now.
Kev
- Log in to post comments
Camshaft bushes
Great care is needed in replacing the bushes to ensure they are the right bore diameter, they are inline with the opposite bush and they must be in the right position so meshing of the timing gears is correct. Not a job to be undertaken lightly!
I needed to replace one of the bushes in my Navigator engine. Once the new (undersize bore) bush was fitted in the drive side case, I set up from the timing side bush. Interestingly, the new bush, after boring, showed that the hole in the case was slightly off centre .
Looking at Peter's drawings, I was surprised that sintered bronze was specified. Ideally sintered bronze should not be machined after fitting, as specified on the drawing, it can "smear" the metal and close the pores that should hold oil.
- Log in to post comments
cam bushes
Good Stuff Kev, Peter & John.
I gave Kev the steer about the Bushes that Neil had - sadly, it sounds like he may have applied the incorrect P no to the 2 bushes he had. I only went by the WebSite.
Interesting note about Sintered Bronze bushes & reaming. Perhaps the factory drawing that Peter reproduced had work notes on it, or with it? Some of the drawings do have machinists instructions with them.
- Log in to post comments
Hi Kev,
Same bushes specified in all lightweights except the very earliest Jubilee without plungers in the drive side ends of camshafts.
After fitting the bushes must have oil holes and other features for lubrication added. Make a note or keep your worn originals to supply to the fitting person.
Then advise fitting person the bushes must be reamed to 15/16 ins bore. The bushes are an interference fit in the crankcase and the bores will shrink 2 or 3 thou on fitting.
Peter