Author Topic: CB350 1971 Restoration Project  (Read 4838 times)

Offline Laverda Dave

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Re: CB350 1971 Restoration Project
« Reply #60 on: May 11, 2022, 09:15:40 PM »
Good progress Ben. That bearing is the worst I have ever seen! The
guy who owned the engineering shop I used to use for rebores (now defunct) was working on a cam bearing shell conversion just before he closed down. He was having trouble getting the clearance correct and staying in place  and not spinning when the engine got hot. Hopefully someone will be able to advise of the clearance you need.
1976 Honda 400/4
1981 Honda CB250RSA
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1982 Laverda 120 Jota
1924 Triumph 550SD
2012 Stanley Battery Drill

Offline BenPowell

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Re: CB350 1971 Restoration Project
« Reply #61 on: May 11, 2022, 09:29:19 PM »
My CB250K had phosphor bronze bushes put in as a modification.  I replaced them in 1985 with standard ones as they had worn out.  I don't know how long they had been in there as they had been done by the previous owner but they looked like a good bit of work.  I still have them somewhere, will try to dig them out.


If you find them some pics would be great, just to see roughly how they look, I plan on putting some miles on the bike and as I said I was lucky enough to to get a NOS cam shaft so I want to make it last.

Good progress Ben. That bearing is the worst I have ever seen! The
guy who owned the engineering shop I used to use for rebores (now defunct) was working on a cam bearing shell conversion just before he closed down. He was having trouble getting the clearance correct and staying in place  and not spinning when the engine got hot. Hopefully someone will be able to advise of the clearance you need.

Yeah it’s quite rough, when I got the bike there was a screw missing from the side cover, which caused an oil leak, so guessing it’s been run low for some time, only 8000 miles on it though, on the other hand the leaking oil kept the frame from rusting.
I’ve got an idea on how to get it to stay in place, it would be a case of making the bush thick enough that when pushed into the housing I can make a drilling on the join line and insert a dowel then finish bore it to size, and for improved lubrication i can cut a spiral into the bush to get the oil flowing better, or even a couple radial grooves might help. Clearances are important to get right, I know a lot about clearances for water hydraulic bearings but not oil unfortunately

 

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