Right rocker arm shaft bolt came out on the way home...

Matnetik

New Member
1974 CB360 -

The other day on my way home, I noticed I lost all my top-end power, then after looking down, I saw oil spewing out of the valve cover and light blue smoke pouring out of the exhaust. After pulling over, I noticed the rock rocker arm shaft must have backed itself out on the freeway. Had no other choice but to plug it with a paper towel and do 10mph for 15 miles to get home (yeah not the smartest idea). Anyway, just took the valve cover off and wanted to get some advice on the best move here. I ordered a new valve cover since the bolt threading for the rocker bolt looked stripped, and the inside of the cover had some stress cracks and chewed up metal where the cam sits. Fortunately the rocker didn’t fall off and destroy everything!

I will drain the oil, clean out the filters, and put some fresh juice in it. One other thing is some oil dripping out of the right exhaust header gasket. I had some oil on me when it broke and may have added too much, thinking this caused a lot of the smoke and the drip. Anyway, any advice on certain parts I should replace or things to clean? Valves have some burnt spots, and I am worried about under the cam (the same place that is cracked on the valve cover), there's a build-up of metal shavings or something. As always, thanks for chiming in on this!!
 

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idahofrank

New Member
Matnitik, you have some damage there. Closer inspection needed, but I figure head, rocker cover, cam, rockers and maybe more ....... Geez, do I have a 360 engine in a shop corner? It's hell getting old!
 

Matnetik

New Member
Matnitik, you have some damage there. Closer inspection needed, but I figure head, rocker cover, cam, rockers and maybe more ....... Geez, do I have a 360 engine in a shop corner? It's hell getting old!
Yeah I bought the bike used and mainly did cosmetic work, curious how it actually looked before this happened. Rocker arms need resurfacing for sure if not replacement. Cam definitely has some chips on the surfaces, why would you say new head? Thanks for the reply, I'm comfortable doing the work myself and have all the tools, just haven't done much engine work except changed the valves on my CBR600RR.
 

teazer

Over 1,000 Posts
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Matnetik, In think that IdahoFrank expects the cam bearing surfaces in the head to be damaged. I would expect so too. If that's the case, the head either needs to be repaired with split bronze bushes or replaced with another stock head.

It may well be cheaper to get a new (to you) head than to repair the damage.
 

irk miller

You've been mostly-dead all day.
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Cam journal in the center (opposite your tach gear) looks bad. There should be a clean oil groove there, but the groove looks filled from overheating and galling the aluminum. You can see where the aluminum is spread along the cam. Your two ignition side rocker pads look very worn and the journal behind the advancer also shows signs of over heating. Did it get really loud right before you lost the plug? The way those pads are worn, good chance that top end was raising hell and maybe vibrated stuff loose. You only have one good journal from what I see in your pics. I don't see the cam well enough in the pics, but it does appear that at least one lobe has pitting.

As Teazer suggests, you can get the head line bored and go with bronze bearings. I've done it on a DR350, because the heads are rare and can cost upwards of $800, so the machine work and bearings were way cheaper. A 360 head seems hardly worth the effort, since they aren't rare.
 

Matnetik

New Member
Cam journal in the center (opposite your tach gear) looks bad. There should be a clean oil groove there, but the groove looks filled from overheating and galling the aluminum. You can see where the aluminum is spread along the cam. Your two ignition side rocker pads look very worn and the journal behind the advancer also shows signs of over heating. Did it get really loud right before you lost the plug? The way those pads are worn, good chance that top end was raising hell and maybe vibrated stuff loose. You only have one good journal from what I see in your pics. I don't see the cam well enough in the pics, but it does appear that at least one lobe has pitting.

As Teazer suggests, you can get the head line bored and go with bronze bearings. I've done it on a DR350, because the heads are rare and can cost upwards of $800, so the machine work and bearings were way cheaper. A 360 head seems hardly worth the effort, since they aren't rare.
Matnetik, In think that IdahoFrank expects the cam bearing surfaces in the head to be damaged. I would expect so too. If that's the case, the head either needs to be repaired with split bronze bushes or replaced with another stock head.

It may well be cheaper to get a new (to you) head than to repair the damage.
Thank you both so much for the detailed responses! The bike definitely got really loud and that’s when I noticed the oil coming out the side. The NOS valve (head) cover is on the way and should be here Monday. Kind of hard to find rocker pads but I am keeping my eye out. I don’t mind replacing the cylinder head but also seems to be a bit hard to find. What I am worried about is taking the head off and then finding even more issues, I was told this motor was pieced together from 3 other motors so who knows what is actually good in there. I’ve only been riding the bike around town - short rides around 10-20 minutes. This was the first time I took it on the freeway and maintained 60-70mph for a solid 30 minutes - this bike has a ton of vibration and from all my little rides I always have to tighten some bolts once I get back. I am going to keep up the oil in there and get some cleaner pictures that might help. Once again, super appreciative of all the feedback and help, I will use the search tool before I ask!
 

crazypj

Split personality, I fake being smart
You need to pull clutch cover and check filter then do the oil flow mods while your in there. The head and cam could be cleaned up and work OK but there will be some damage on the middle cam journal. If it isn't across the entire journal it's salvageable without much expense but a bit of hand work.
There is a guy near Seattle who will do rocker repairs at a reasonable cost but I forget name at present
 

Matnetik

New Member
You need to pull clutch cover and check filter then do the oil flow mods while your in there. The head and cam could be cleaned up and work OK but there will be some damage on the middle cam journal. If it isn't across the entire journal it's salvageable without much expense but a bit of hand work.
There is a guy near Seattle who will do rocker repairs at a reasonable cost but I forget name at present
Hey thanks for the info, I have been looking up a lot of the oil mods. Going to send my rockers and cam off to common motors in Houston, they weld and resurface the rockers and resurface the cam for $200! the NOS Valve cover came in a few days ago and the guy included the rocker arm bolts. Once I get the cam out this weekend I am going to check out the head journals, that's my main concern. Especially because I have been checking eBay daily for a decent condition cylinder head and can't find any. Will update photos here once I get the cam out. Probably just going to tear down the head and check the valves, pistons and rings as well, would really like to be able to ride this thing on the freeway for 30 minutes without having to worry about it blowing up ha
 

Matnetik

New Member
Another thing to check is to see if you have the updated slipper tensioner installed. The tensioner holder appears to be the old version, which would indicate the slipper has not been updated. Here are the Honda bulletins:
https://www.hondatwins.net/threads/360-bulletins-re-posted.4382/
Brilliant, seems like the engine casing has both stamps on it but who knows with how it was rebuilt - will check this too, thanks! Also looking at the tensioner holder, it doesn’t look like it was updated with the recall parts.
 
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Matnetik

New Member
Update here: Ordered the tensioner holder, damper, going to pull out the slipper this weekend and check the condition and it's if the old one or new one - common-motors also manufactures these so I will get one with the cam/rocker resurface from them pending my situation. Once I get the cam out and take the head off I will get some pictures up of the head to figure out my options. Thanks everyone for all the help, info and feedback on this, beyond appreciative!
 

crazypj

Split personality, I fake being smart
I didn't know Brendan was doing cams and rockers, that's a good price.The 'new' tensioner blades were based on a slightly worn one but they work fine (I was involved a bit with the development) I thought Sparc Moto was making them, maybe CMC took over?
The top tensioner holder will be straight if original and have 'wings' pointing at an angle if it's the new style.
You can scrape and polish head journals, as long as they are round and close to correct diameter there won't be a problem. It's also possible to get them machined for ball bearings with a bronze bush on centre journal but not sure who's actually doing that nowadays
 

Matnetik

New Member
I didn't know Brendan was doing cams and rockers, that's a good price.The 'new' tensioner blades were based on a slightly worn one but they work fine (I was involved a bit with the development) I thought Sparc Moto was making them, maybe CMC took over?
The top tensioner holder will be straight if original and have 'wings' pointing at an angle if it's the new style.
You can scrape and polish head journals, as long as they are round and close to correct diameter there won't be a problem. It's also possible to get them machined for ball bearings with a bronze bush on centre journal but not sure who's actually doing that nowadays
Yeah I went ahead and purchased the new style holder and damper. Still need to pull the slipper out. I am not sure how Brendan does the rockers though, I know Web Camshafts hard welds the rockers for longer life but they charge $72.00 each and their cam prices are around $500 which is WAY more than I would spend on this thing. There is some pitting on the cam though so I do want to have it resurfaced at the least, Brendan said there's about a 12 week turnaround time unfortunately.
 

irk miller

You've been mostly-dead all day.
DTT BOTM WINNER
$500 is insane. Maybe SBC stuff is just that cheap, but a regrind on a small block Chevy camshaft is $150 max. I guess maybe I'm using a false equivalency. I wonder if they're sending the cam out, so you are paying double for them to be a go-between. I really can't make sense of a $500 price tag.
 

crazypj

Split personality, I fake being smart
Web Cams and 'the other one' charge about $500 as well.
They say it's due to lack of demand so machine has to be re-set all the time. From the little I know of cam grinding machines though that's BS and $120~$150 would be more realistic price.
It's the price that puts me off gewtting a 'semi-race' cam for 360's, having multiple motors would get to bankrupt me pretty quick :D
Doing a SBC or V-8 Ford, when machine is set up would be pretty quick rerally, even though there are more lobes so $150 is gives a very nice profit
If you look at DOHC motors the prices are also pretty crazy.
Of course, you often get inflated quotes as they probably have no interest in actually doing 'one off' cam grinding
 

Matnetik

New Member
Okay, so little update here. I have received a ton of new parts which is great, starting to put things back together, still need to get the cam out and inspect it a bit more. Instead of sending off my rockers, I found some great condition ones (at least compared to my old ones haha) since the turnaround time was so long. But, depending on the cam, I may have to send that out, wouldn't want to ruin these nice rockers. Still waiting on the other two to show up. Also got a ton of new gaskets to replace the old ones for everything I have taken off and new oil gaskets for everything in there once I do the change. The new cam tensioner is also here with all the replacement parts so I am going to put that in soon! Here is a picture of my old rockers haha and the new valve head/rockers-

Also found an 18" baffle for my exhaust, have to have it cut down to 12" and welded in, hopefully will create a bit more back pressure and make it a bit quieter!
 

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Matnetik

New Member
More updates, found another set of rocker arms and a cam shaft with minor pitting - I mean, compared to what’s in there now, this thing is like new! Plan is, rebuild with these parts, send off old rockers and old cam to get resurfaced since it’s such a long turnaround - trying to get some mountain riding in this fall!
 

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