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I've begun a full teardown and rebuild on my CB360, and am in the process of engine/transmission dissassembly. In looking at my cylinder walls and pistons, there is some scoring. Before dissassembly, my compression numbers were a bit low (150ish if I remember correctly). While the engine is apart, I'd like to get the bores machined, and get some oversized pistons and rings.

I'd like some opinions on oversized pistons and rings for the budget minded garage restorer. I hear that Honda still stocks oversized pistons and rings. I've also heard that CB450 pistons work well. How far oversize should/can I go? I've done some research around here, but haven't found anything definitive.

Thanks in advance,

-MK
 

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Hey everybody. New post on a super old thread, I know. But, I'm in a similar predicament with choosing pistons for a cb360. I have a knack for choosing unusual or challenging projects rather than just going the easy route, and I would love to make a "sleeper" out of a cb360. I've done a lot of research on piston swaps in cb360's, and have seen the gs850 pistons are a common and fairly straightforward swap. However, they are harder to come by, and fairly expensive when they do show up. I had in mind something around the 69-70mm bore size, as this is the maximum "safe" diameter I've seen a cb360 sleeve bored to. CB450 pistons are 70mm stock, have two valve reliefs, and are seemingly much easier to find. However, the wrist pin diameter is 17mm vs 16mm, and I can't seem to find any specifications on the pistons such as compression height, skirt length, etc. to confirm if these pistons are a viable swap into a CB360. My current wrist pins seem to have a little "wobble" in the small end of the connecting rod, so honing/boring the small end of the connecting rod from 16mm to 17mm doesn't seem to outrageous....? Or perhaps they could be machined to a press fit rather than a full floating wrist pin? Anyway, I would love to hear some sage advice from a Honda twin veteran who might have first hand experience with this. I realize I could probably purchase a "junk" cb450 piston for size comparisons, but figured I should ask before I leap. The stock cb360 bore size is 67mm, with common oversizes in 0.5 and 1mm over, from what I've found. So cb450 would be 3mm over. Thanks in advance for any feedback, I suppose I should open a thread on my build at some point... lol
 
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