Author Topic: Line boring camshaft and pinion bushings  (Read 882 times)

Offline roadrocket

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Line boring camshaft and pinion bushings
« on: 20.02. 2011 15:15 »
Hello!

I have tried to search the web for information about the nature of line boring the A10 camshaft and timing side pinion bushings. I fear these are getting a bit worn after 57 years, and now that I have to split the cases to fix a crack near a barrel stud, I might just as well see to the bushings. Will it suffice to ream the bushings after new ones have been installed and temporarily fix the inner timing cover? Or is line boring something more sophisticated like the procedure required for the crank main? I know I should renew the blind bush in the drive side as well, but this is most likely too cumbersome, and renewing the two others must be to some advantage?

Regards, Otto in Denmark
Otto in Denmark

Offline BSA_54A10

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Re: Line boring camshaft and pinion bushings
« Reply #1 on: 21.02. 2011 12:26 »
Bearings on the same shaft must always be replaced as a set.
You risk bending the shaft if you don't and at the very least the shaft will not have sufficient support area and will very rapidly wear the new bushes out the be in line with the old one again.
Bike Beesa
Trevor

Offline terryk

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Re: Line boring camshaft and pinion bushings
« Reply #2 on: 21.02. 2011 14:25 »
An engineering shop should be able to line bore them with a milling machine etc. You will need to take the cam you intend to use as well.

The blind bush can be removed by tapping a thread in it, then screw in a bolt of the same thread, then heat the case in that area and hit the bolt head and the bush should come out. The new bush can be pressed in while the case is hot or put new bush in the fridge for a bit and it should drop in.
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Offline roadrocket

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Re: Line boring camshaft and pinion bushings
« Reply #3 on: 21.02. 2011 16:36 »
Thanks chaps!

I thought I was taking Bodgery Lane again... I will now either leave as is, or go along the path of of righteousness, and get it all done by people who know.

Otto in Denmark
Otto in Denmark