CB360 Head Work

M

motormayhem

Active Member
Hey guys,
I just picked up a CB360T for $150. From what I have been reading they are not quite as serviceable compared to the cb350's with respect to the cam bearings or lack there of. I haven't torn this one down to see if it needs anything, but I was doing some reading on converting the cam to a needle bearing setup. I could do this over the course of the next few months as I currently am in school and have a machine shop at my disposal. All the posts I could find on the subject were old and none of the pictures worked so I guess my question is does anyone know where to start with this? I'm mostly concerned with keeping oil going to the right places as I know the needle bearings will change that significantly. Also where is a good place to find parts and info for these bikes?


Thanks,
Miles
 
Why bother, unless you have some crazy plans for this bike? By "valve bearings" I assume you mean camshaft bearings, which are, of course, plain bearings in the cb360.

And they work pretty damned good as from factory, as I recall, so again, wondering why you'd need to move to a needle bearing setup?
 
I dont have any crazy plans yet. I was mostly considering doing it because it seems like a lot of people say these motors eat through the aluminum the cam rides on pretty quick and destroys the head. Just looking to make this bike as reliable as possible before my access to a shop ends when I graduate in December.
 
That happens because people do not take care of their bikes.
Proper and frequent oil changes and levels pretty much negate that kind of issue.

If I remember correctly, the real problem was exhaust valve and guide wear. The angle of the tappet or soe such causes this, and bad oil levels make it worse.

Ask crazypj.
 
The issue with the 360s is that they don't do well if held at high RPMs for extended periods of time. The oil pressure bypass is a little too effective and the head can suffer from oil starvation if you rev the heck out of it. There are a few modifications you can make and roller bearings are not unheard of.
 
I cant imagine going through the process of a needle bearing setup for an otherwise mostly stock bike.
 
Cool, well thats good to hear. Reading on some other forums made it sound like these bikes were trash, but it seems pretty solid to me. I'd like to build it up a little and do a mild cafe theme to it, but keep the engine pretty much stock for now ( I know there isn't much aftermarket for these motors). Besides the center cam bearing and chain tensioner is there anything else that is good to fix or do to these bikes? '

Also it seems like people recommend running 5w-40 to help with cam wear on these bikes, but looking through the manual it recommends 10w-30, 10w-40, or sae 30 as oils for warmer temps. I know the idea behind running 5w-40 is to run a little lighter weight oil for high rpm operation, but is there any downside to running 5w-30 since it seems like the manual is ok with 30 weight oils and thats even thinner than 5w-40 when warmed up?

Thanks for the info guys!
 
The w rating is the "Winter" rating. 5w-40 is fine. The 40 is the important part. I use Shell Rotella T 5w-40 synthetic myself.


Sent from planet Earth using mysterious electronic devices and Tapatalk
 
The little 360 that I did that modification on in that thread Myd posted is still running great, no weird noises or problems with oil starvation that I can tell. It starts and runs like a bat out of hell, well as fast as a 360 can. I would recommend doing the center drilling to anyone that plans on pulling the head off to do any other maintenance. I will be pulling that engine this winter to redo the paint and I will be revisiting the head to see how things turned out.

Otherwise, there are a few things I have learned about how they act when you either park them or start them. When you park them on side stand the left side bowl that holds the oil that lubes that side of the cam can drain back into the crank case in about 2 minutes, leaving that side pretty much dry. I tested this several times with the cam cover off before I drilled the head. If you plan on parking the bike for longer than 5 minutes, do so on center stand since that it will limit the amount of oil that flows back into the crank case.

When you start them, leave them at an idle for at least a minute before reving them much over an idle you want as much oil up top as possible before you start making things work hard. Mine is a little cold blooded and won't hold an idle by itself without me helping, so I just start it when I'm ready to go sitting on the bike. MOST of the damage is done right at start up by morons that rev the piss out of the engine right off. The left side will be sitting with no oil, grinding away metal to metal. The left side cam bearing is also smaller than the other two without any oil will just wear that much faster.
 
mydlyfkryzis said:
The w rating is the "Winter" rating. 5w-40 is fine. The 40 is the important part. I use Shell Rotella T 5w-40 synthetic myself.
Sent from planet Earth using mysterious electronic devices and Tapatalk
Click to expand...
Right, the 5 weight rating is for when it is cold or coming up to operating temp, but would a 30 weight hot rating be better than a 40 weight as it is a little thinner? Just curious since I haven't really played with oils much.

Frogman, thanks for the info about startup. I'll try to keep as much oil in the top end as possible!
 
frogman said:
The little 360 that I did that modification on in that thread Myd posted is still running great, no weird noises or problems with oil starvation that I can tell. It starts and runs like a bat out of hell, well as fast as a 360 can.
Click to expand...

It should be good for 105mph if everything is 'right'. Modded 378cc conversion with some mild porting and decent exhaust is good for 120mph
I can 'fix' early 450 DOHC carbs as well as 360 and 350's (they are all the same type but not the same size)


motormayhem said:
Right, the 5 weight rating is for when it is cold or coming up to operating temp, but would a 30 weight hot rating be better than a 40 weight as it is a little thinner? Just curious since I haven't really played with oils much.
Click to expand...

5W/30 is fine, it just means the hot temp thins as much as a 30 wt or 40 wt would at 100 deg C
When you get to actual operating temp (220 C or so) there really isn't much difference
 
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