From the 1961 fiche, CA and CB have the same part number:

CYLINDER 12100-267-000 So yes, at least in 1961, they are the same.

 

Excellent. Thank you for the quick response. I will just double check the years that I am dealing with.

Where do you get your parts numbers from online? I used to use a source to compare stuff but they stopped listing the part numbers if they didn't have it in stock. Thank you again.
Billy

 

Hi,

CMSNL.com is a good place for obtaining part numbers.

Anyway, make sure you dont use the 000 version on later engines, check the amount of holes !

What you see hre are some early 8 hole cylinders from very early bikes. Later cylinders have an extra oil hole.
If you mount an early cylinder on later crank cases, oil is not getting to the cylinder head !!!

Also make sure you get the right gasket.

 

What about the other way around? What if you were to put a late cylinder on an early crank case? I would think that the oil flow would take the path of an early model and have no problems...thoughts? Thanks!

 

Why not just change the cylinder liners rather than mixing and matching the whole assembly? Then you've got no worries when it comes to oilways or any other passages.

Stick the barrel assembly from the bike in the oven at around 200deg C for about ten or fifteen minutes and you should find the liners drop out - you sometimes hear a clang as gravity acts on the case and it drops down the liners. Repeat with the donor and while they're hot, switch the liners from one to the other. Place the final assembly face down (so the face that mates with the head gasket is resting on the tray) and heat it to get the liners in place. Again, gravity is your friend but this time it's to get everything seated.

Once everything's cooled down, check for flat on the head gasket face. You may need to flat that face with sandpaper if there's any discrepancies. Search YouTube for flattening an engine block to see how easy it is.

 

Thanks for the fast reply! I agree with what you are saying but unfortunately the only early jug I had was in terrible condition with many busted fins. The way it looks is that it should just bypass that additional port and function like an old head since all the old ports are open all the same.

 

Putting a newer set of cylinders on an older bottom end might not be a problem, but that'll depend on whether the diameter of the holes on the '8' version (which I assume are engine stud holes) that are responsible for carrying the oil to the top end. So long as there's sufficient clearance for oil to be pumped to where it needs to be, go for it.

Chances are Honda used the same bore for all of the studs, so if that checks out - and everything else lines up - you should be OK.