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CB350 1971 Restoration Project
BenPowell:
That's a good sign, will take a look at the ebay store. starting to look like really good value.
Thanks
Bryanj:
Those are good value and i know if Trigger uses them they are good. You do need to get a reborer who knows Hondas or they will bore it too big because they think Hondas clearances are too small
BenPowell:
I’ve done some work on the cylinders tonight and had a go a cleaning up the pitted bore, I’ve got out a lot of the pitting but there is a fair bit which still remains, although it doesn’t feel too bad.
I’ve also dug out one of the bore micrometers from work and took some readings.
I used the untouched section of the good bore as a reference, measured 64.02mm which is standard spec for the engine. The worn section of the bore was 64.04mm.
Then measured the pitted bore, the bottom measures 64.06mm and the top section 64.11mm.
The pitted bore is right at the limit stated in the manual (diameter 64.1mm and taper 0.05mm) and as there’s still some pitting remaining I’m probably going to go for a re-bore, at least that can be getting done while I work my way through the other engine parts.
AshimotoK0:
--- Quote from: BenPowell on June 30, 2021, 07:00:24 PM ---I’ve done some work on the cylinders tonight and had a go a cleaning up the pitted bore, I’ve got out a lot of the pitting but there is a fair bit which still remains, although it doesn’t feel too bad.
I’ve also dug out one of the bore micrometers from work and took some readings.
I used the untouched section of the good bore as a reference, measured 64.02mm which is standard spec for the engine. The worn section of the bore was 64.04mm.
Then measured the pitted bore, the bottom measures 64.06mm and the top section 64.11mm.
The pitted bore is right at the limit stated in the manual (diameter 64.1mm and taper 0.05mm) and as there’s still some pitting remaining I’m probably going to go for a re-bore, at least that can be getting done while I work my way through the other engine parts.
--- End quote ---
The tolerances in the Shop Manuals are pretty wide Ben and quite often for the the limits given... we on here would probably deem as being fooked. Trigger is your best bet for a decent rebore but he will need the pistons at the same time I think. You will probably have to go for at least +0.5 ..possibly +0.75 but I am not sure if Cruzin do +0.75.
BenPowell:
Yeah there’s no life left in that bore anyway.
I think by looking at it I would probably get away with 0.50, I might keep going with the cleaning up and measure it once the pitting is out to see what the size is, suppose that’ll tell me what piston size I will have to go with then, or could go with 0.75 to be sure.
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