Crank cases

[florence]

Very simple question, are Honda crank cases machined as a pair or are they able to be mixed?, i.e top crank case from one engine and the bottom one from another?

[hairygit]

The cases for shell bearing cranks ( mainly 4 cyl engines) are machined as matched pairs, roller bearing cranks such as your 350 are not, and you can mix and match casings for those.

[florence]

thank you sir!

[AshimotoK0]

The cases for shell bearing cranks ( mainly 4 cyl engines) are machined as matched pairs, roller bearing cranks such as your 350 are not, and you can mix and match casings for those.

Another thing is that even though the top crankcases changed throughout the '68->'73 run,  the lower crankcase can be fitted from any model 250  or 350 CB or CL. Beware the SL engine though, the K0 had basically the same engine as the CL and the CB but later on almost everything is different on the deletion of the electric starter, the crank, the cases, the carbs etc etc. are all different. Almost got caught out on that one myself!

[florence]

good, this means I can start building another engine, otherwise I know what will happen, I'll take out the old engine then the bike will sit around in the workshop and by the time I put it back together, important parts will have evaporated.