SOHC.co.uk Forums > SOHC Singles & Twins

Early 70’s CB250

<< < (8/9) > >>

Bryanj:
400 or 500 would probably fit ok even 750 if wiring goes through the bars

Andych:
I was told to tidy up all my crap in the main garage so I decided to have a quick look at the CB360 engine to see if it was worth salvaging as the head was absolute toast.. as was the camshaft.
Well the barrels are pretty good and when I separated the cases all inside looks to be really good.. Crank is nice and free and conrods look and feel nice as well..
I also whipped the rocker cover off the latest bike to see what the can etc was like and it is like brand new.. at least as far as I can see.. I will need to take it out of the frame and strip it down.. if only to replace the gaskets (currently silicon sealant) and make sure all oil galleries etc are OK.
I would like to build up the 360 engine as a possible donor for the bike but I am short 1 Cylinder hear and they seem to be in short supply. I did find one in the USA but it will need valves, seats etc and even before that it will cost me close to A$500 landed.
I asked this question in Honda Twins and have not had an answer so I was hoping somebody here might know.. can the 250 head be machined out to suit the 360 piston crown?
I have a spare 250 head with really good cam journals and looking at it the combustion chamber seems to be the same apart from a large chamfer to account for the larger diameter Piston crown.
I guess I could always take it to my machinist and have him look at it..
Valves are identical between the 2, as is stud spacing etc. It may end up a better option for me than trying to source a 360 head.

It is actually better in the flesh than the pic looks
[ Guests cannot view attachments ]
[ Guests cannot view attachments ]

As I said.. the cam and head are toast
[ Guests cannot view attachments ]
[ Guests cannot view attachments ]

AshimotoK0:
Sorry I can't be 100% certain but I know on the CB250/350K head, the chamfer on the 325cc head is the only difference.

I never seem to get much response from question on Hondatwins forum either... dare I say it on here....  you are likely to get a quick answer on the relevant Facebook group.

If you don't use FB I can ask for you.

Andych:
Thanks Ash
I will get a chance to mostly measure it up this weekend.
I figure if the chamber shape is the same and the dome height is the same it should only be the chamfer that’s is the difference.
I have had 25 odd views on the post but no comments at all.
Certainly not as helpful or friendly as in here


Sent from my iPhone using Tapatalk Pro

K2-K6:
We had a thread on here a few years back discussing the chamber shape on these (I can't currently find it) that covered it in detail that may be worth finding.

Navigation

[0] Message Index

[#] Next page

[*] Previous page