CB360 "high rpm" oiling problem ?
- Thread starter dp9
- Start date
crazypj
Split personality, I fake being smart
You can only make some sort of educated guess.
cruising at a steady 6000rpm should be fine forever, 7,500rpm should be OK for tens of thousands of miles
It's fine to run it to red line (and beyond
) when accelerating, but, not to hold it there
Problem is, not sure if it's a cumulative effect?
Bits wear a little, metal particles get embedded, oil pressure drops and cam seizes, or, high rpm, oil pressure drops to cam, and rockers overheat, cause oil breakdown, then bearings 'pick up' or seize
I couldn't really say a definite rpm as some motors seem to run fine at higher rpm (although I haven't stripped one recently)
I would say sustained 9,000 or more rpm and something bad will happen, but, it still takes several miles and does seem to be cumulative (cam is done around 130~170 miles of 5th/6th gear running, even with pulling clutch and allowing rpm to drop every 3~5 miles)
It was never designed to be beat up and down interstates or motorways (although I knew several people who did it, me included )
At present, the 'secret weapon' is Shell Rotella 5w/40 full synthetic
Idle speed probably needs to be slightly higher than normal to keep oil pressure up at idle (have mine set around 14~1500)
I'm still working/playing with remote oil line to head and drilled cam, probably the most cost effective way to go, pretty sure just about all 360's are eventually going to 'eat' the top end eventually (except for a few modified ones )
The worst thing you can do is use thicker oil (40 wt, 20w/50, etc)
cruising at a steady 6000rpm should be fine forever, 7,500rpm should be OK for tens of thousands of miles
It's fine to run it to red line (and beyond
) when accelerating, but, not to hold it thereProblem is, not sure if it's a cumulative effect?
Bits wear a little, metal particles get embedded, oil pressure drops and cam seizes, or, high rpm, oil pressure drops to cam, and rockers overheat, cause oil breakdown, then bearings 'pick up' or seize
I couldn't really say a definite rpm as some motors seem to run fine at higher rpm (although I haven't stripped one recently)
I would say sustained 9,000 or more rpm and something bad will happen, but, it still takes several miles and does seem to be cumulative (cam is done around 130~170 miles of 5th/6th gear running, even with pulling clutch and allowing rpm to drop every 3~5 miles)
It was never designed to be beat up and down interstates or motorways (although I knew several people who did it, me included
)At present, the 'secret weapon' is Shell Rotella 5w/40 full synthetic
Idle speed probably needs to be slightly higher than normal to keep oil pressure up at idle (have mine set around 14~1500)
I'm still working/playing with remote oil line to head and drilled cam, probably the most cost effective way to go, pretty sure just about all 360's are eventually going to 'eat' the top end eventually (except for a few modified ones )
The worst thing you can do is use thicker oil (40 wt, 20w/50, etc)
dp9
Coast to Coast
Thanks PJ! I'll throw rotella in on my next oil change.
I dont have a tach, but I can "seat of the pants" it, or do the calculations when I'm feeling less lazy. 130~170 miles in top gear and the cam is DONE?! no matter what??? or do you mean running at 9 grand for that many miles?
where do you measure oil pressure? I forget if there is an oil light because its been so long since i took the idiot lights off :
I'm interested to see how you solve the oiling problem. Ive heard about putting needle bearings in, but havent looked too far into that. running lines direct to the head would allow for an oil cooler too ;D . been wanting to do that for a while now.
I dont have a tach, but I can "seat of the pants" it, or do the calculations when I'm feeling less lazy. 130~170 miles in top gear and the cam is DONE?! no matter what??? or do you mean running at 9 grand for that many miles?
where do you measure oil pressure? I forget if there is an oil light because its been so long since i took the idiot lights off :
I'm interested to see how you solve the oiling problem. Ive heard about putting needle bearings in, but havent looked too far into that. running lines direct to the head would allow for an oil cooler too ;D . been wanting to do that for a while now.
crazypj
Split personality, I fake being smart
130~170 miles at 9K or more will kill top end
Holding motor over 9K will probably start rattling around 30~50 miles, damage starts happening about 10 miles in
There is no oil light, it would only irritate you flashing on and off ;D (and would probably be worthless as Honda only use a 4psi switch : )
There is no easy way of measuring oil pressure without drilling and tapping crankcase or clutch cover
If you keep it around 70mph in top gear (and correspondingly lower in lower gears) you should be fine.
I have a spare head and a few NOS rocker arms as I'm pretty sure I'll need them (hopefully, NOT )
I'm going to do a 'long term' test of oiling mods and find out (couple of thousand miles then pull top end for a look)
May take a while though, haven't been able to ride bike for months and last time I tried I could only do about 6 miles without stopping to rest my arm (I did manage 19 miles in total though 8) )
Holding motor over 9K will probably start rattling around 30~50 miles, damage starts happening about 10 miles in
There is no oil light, it would only irritate you flashing on and off ;D (and would probably be worthless as Honda only use a 4psi switch :
)There is no easy way of measuring oil pressure without drilling and tapping crankcase or clutch cover
If you keep it around 70mph in top gear (and correspondingly lower in lower gears) you should be fine.
I have a spare head and a few NOS rocker arms as I'm pretty sure I'll need them (hopefully, NOT
)I'm going to do a 'long term' test of oiling mods and find out (couple of thousand miles then pull top end for a look)
May take a while though, haven't been able to ride bike for months and last time I tried I could only do about 6 miles without stopping to rest my arm (I did manage 19 miles in total though 8) )
dp9
Coast to Coast
thanks for the clarification. I can probably keep it around 70 on the highway. worst case scenario I can plan a longer trip using the "avoid major highways" function on google maps.
I wish there was an easier way to put a gauge in. That would be great to have. I dont have any spare motor parts, so 'll be playing it conservatively.
keep up with your rehab therapy. thats what gets you back to normal.
Thanks again for all the info.
I wish there was an easier way to put a gauge in. That would be great to have. I dont have any spare motor parts, so 'll be playing it conservatively.
keep up with your rehab therapy. thats what gets you back to normal.
Thanks again for all the info.
frogman
'74 CB360, '71 CB450, '75 CB550SS
One thing I can say with mine is that if you change the gearing some, you can move that cruise RPM down a bit and maybe help with longevity of the engine.
As an example I'm running a 17 tooth front sprocket which has helped to lower the cruising RPM by about 1000. Most of the roads I drive are 65 mph so 5200-5500 is about where that is and the bike does just fine pulling my skinny ass up most of the hills. Yes passing a car requires 2 down shifts but it still goes around with no issues. It gets up and goes just fine, just not as fast as it did before. I'm more looking for a rider that I can get places in, not one that will go 0-60 in 3.2 seconds. 70-75 is right around 6200, hard to tell with the old tach.
I was sorta studying the ignition side cam journal and I almost wonder if the placement of the grove that is supposed to fill that bath tub with oil is in a bad spot. The oil will flow path of least resistance and that is right out the hole then right out of the slot into the tub and not UNDER the cam. I have a couple of heads that I have gathered up, both will get drilled for the oil passage for the center bearing and I am thinking one will get that notch welded up and maybe a slight grove cut in under that journal to help the oil get under the cam.
As an example I'm running a 17 tooth front sprocket which has helped to lower the cruising RPM by about 1000. Most of the roads I drive are 65 mph so 5200-5500 is about where that is and the bike does just fine pulling my skinny ass up most of the hills. Yes passing a car requires 2 down shifts but it still goes around with no issues. It gets up and goes just fine, just not as fast as it did before. I'm more looking for a rider that I can get places in, not one that will go 0-60 in 3.2 seconds. 70-75 is right around 6200, hard to tell with the old tach.
I was sorta studying the ignition side cam journal and I almost wonder if the placement of the grove that is supposed to fill that bath tub with oil is in a bad spot. The oil will flow path of least resistance and that is right out the hole then right out of the slot into the tub and not UNDER the cam. I have a couple of heads that I have gathered up, both will get drilled for the oil passage for the center bearing and I am thinking one will get that notch welded up and maybe a slight grove cut in under that journal to help the oil get under the cam.
Treesus
Probably not sane.
DP9,
Sorry to bring this back up again if you've already put everything at ease in your mind or taken the trip.
I took my '74 360 on a 3,500 trip cruising between 55-75mph (indicated, anyhow) with the stock gearing and my head is still doing alright for now with no mods. This was before I began to understand the head oil issues, but luckily I was changing the oil about every 800 miles out of beginner paranoia. So nothing clogged.
I stuck to state highways because of a combination of wanting to actually see the passing scenery, and because at elevations of 4,000-10,000 ft out west where I was traveling, I didn't feel comfortable keeping up with the 80+mph traffic.
Anyhow, I think if you keep the oil clean, keep the speed reasonably down, and (as they said) use a good thinner oil, then you should be pretty safe.
That being said, I am working on modding my head before any more long trips...
Tree
Sorry to bring this back up again if you've already put everything at ease in your mind or taken the trip.
I took my '74 360 on a 3,500 trip cruising between 55-75mph (indicated, anyhow) with the stock gearing and my head is still doing alright for now with no mods. This was before I began to understand the head oil issues, but luckily I was changing the oil about every 800 miles out of beginner paranoia. So nothing clogged.
I stuck to state highways because of a combination of wanting to actually see the passing scenery, and because at elevations of 4,000-10,000 ft out west where I was traveling, I didn't feel comfortable keeping up with the 80+mph traffic.
Anyhow, I think if you keep the oil clean, keep the speed reasonably down, and (as they said) use a good thinner oil, then you should be pretty safe.
That being said, I am working on modding my head before any more long trips...
Tree
crazypj
Split personality, I fake being smart
Brendon has been riding his 360 at high rpm with Rotella 5w/40 full synthetic with a small amount of ZDDP and hasn't had any issues (yet)
Done about 2,000 miles, 100~200 miles at a time.
Things don't get blocked so new oil every 800 miles is just a waste of resources.
Using thinner better quality oil seems to be the secret to prevent over pressure?
Done about 2,000 miles, 100~200 miles at a time.
Things don't get blocked so new oil every 800 miles is just a waste of resources.
Using thinner better quality oil seems to be the secret to prevent over pressure?
frogman
'74 CB360, '71 CB450, '75 CB550SS
This is what I did to the replacement head I just put on my bike after the last thread on the right side holding the sparkplug in gave out. I have 2 spares and I knew about the plug hole before I put things together. I may fix it one day I may not, bearing looks a lot worse than it is, was full of crap and grime.
Yes I drilled the gallery out, was a PAIN.
I used a 1/4" set screw and some silicone to close of the end, I wanted to be able to clean out the gallery if need be.
Had enough room to clear the advance unit
Next part was to JB weld the notch up on advance/points side. I didn't take a final picture but I went back and cleaned off the surface the cam comes into contact with so there would be no issues there.
With all that done and like a bone head I didn't take final pictures with everything on. I put the cam in and got it tensioned correctly then kicked the kicker till I got oil up top and watched the difference. The point side bearing flowed better than I remembered from the last time I was in there and watched it. The oil now passes over the top of the bearing and exits the front side into the bath tub instead of right off like before. There are plenty of places for it to get to the tub, it just has to go around a little bit more.
The Center bearing required me to clamp on the spare valve cover that I have without the followers in it and then kick the heck out of the engine for a while to get that center passage to flow. And it did, and I am happy. Time will tell, it has been too freaking cold to ride much but I took it out for a quick 20 mile spin right after the goop set under the valve cover and worked it hard the entire time. Ran like a champ, made no weird noises, timing needs to be reset again but it usually takes 2 tries to get it right and I wanted out of the house that day. 8)
That was just part of it, but it looks like a nice weekend around here in the high 40's, will prolly taker her out for a nice easy ride and put 100+ miles on it, see what happens. IF it grenades I still have 2 heads that work. IN reality it would have taken less time to fix the plug hole but would have cost me 35 bucks and still needed me to take the head off. The only cost to me for drilling out that center passage was the aircraft drill bit that was 4 inches longer than standard and I got it on sale for 3 bucks, regularly 7. I had the JB weld and the time, and the gaskets. Well, there was the 12 pack of beer but who's counting. :
Yes I drilled the gallery out, was a PAIN.
I used a 1/4" set screw and some silicone to close of the end, I wanted to be able to clean out the gallery if need be.
Had enough room to clear the advance unit
Next part was to JB weld the notch up on advance/points side. I didn't take a final picture but I went back and cleaned off the surface the cam comes into contact with so there would be no issues there.
With all that done and like a bone head I didn't take final pictures with everything on. I put the cam in and got it tensioned correctly then kicked the kicker till I got oil up top and watched the difference. The point side bearing flowed better than I remembered from the last time I was in there and watched it. The oil now passes over the top of the bearing and exits the front side into the bath tub instead of right off like before. There are plenty of places for it to get to the tub, it just has to go around a little bit more.
The Center bearing required me to clamp on the spare valve cover that I have without the followers in it and then kick the heck out of the engine for a while to get that center passage to flow. And it did, and I am happy. Time will tell, it has been too freaking cold to ride much but I took it out for a quick 20 mile spin right after the goop set under the valve cover and worked it hard the entire time. Ran like a champ, made no weird noises, timing needs to be reset again but it usually takes 2 tries to get it right and I wanted out of the house that day. 8)
That was just part of it, but it looks like a nice weekend around here in the high 40's, will prolly taker her out for a nice easy ride and put 100+ miles on it, see what happens. IF it grenades I still have 2 heads that work. IN reality it would have taken less time to fix the plug hole but would have cost me 35 bucks and still needed me to take the head off. The only cost to me for drilling out that center passage was the aircraft drill bit that was 4 inches longer than standard and I got it on sale for 3 bucks, regularly 7. I had the JB weld and the time, and the gaskets. Well, there was the 12 pack of beer but who's counting. :
dp9
Coast to Coast
PJ: am i reading that speedo right? youre comfortable doing 90 for extended periods of time with the rotella?
side note: is 378 the biggest you can go? any way to stroke this little engine?
frogman: thats a great write up, man! I'm trying to keep this top end alive without opening it up, but with that road map you posted I'm not entirely concerned about it any more, laugh. I may even pick up another head to mod!
side note: is 378 the biggest you can go? any way to stroke this little engine?
frogman: thats a great write up, man! I'm trying to keep this top end alive without opening it up, but with that road map you posted I'm not entirely concerned about it any more, laugh. I may even pick up another head to mod!
frogman
'74 CB360, '71 CB450, '75 CB550SS
I was going to do that to my first head but it is a different casting and the points area doesn't not allow easy modification like the head I replaced it with. If you do get a head make sure the points area looks like that. Cheap decent spares show up all the time on eBay, I've gotten most of 3 engines for less than 200 bucks that way.
Sun is gonna be shining here in about an hour, temps gonna top out at 50 today, may just take the silly thing to work today. 8) ;D
Sun is gonna be shining here in about an hour, temps gonna top out at 50 today, may just take the silly thing to work today. 8) ;D
crazypj
Split personality, I fake being smart
You can't stoke it without a lot of work. 378cc is about biggest you can easily bore (pretty much plug and play )
I'm going to build a 74mm motor but its a lot more work.
Been thinking of a stroker but crank pins are machined directly onto flywheel forging on one side (makes crank more rigid)
If I had a spare 'dead' crank I would try it, I think a full 500 may be possible but would also have to source rods, pins and pistons with shorter crown height
It was still accelerating in pic, went 'off the clock' (on a slight downhill) probably only a mile or two.
That motor as already done multiple dyno runs with various carb and exhaust configurations (right up to major points 'bounce', around 12,500rpm)
I've posted dyno runs in build thread, power varied fron ~33 to 40 bhp ( for comparison, stock GS500 twin made around 36~38bhp, DRZ400SM, 36bhp)
Brendon is running 80+ for extended periods though (his speedo is running slow, thought it was 70~75)
)I'm going to build a 74mm motor but its a lot more work.
Been thinking of a stroker but crank pins are machined directly onto flywheel forging on one side (makes crank more rigid)
If I had a spare 'dead' crank I would try it, I think a full 500 may be possible but would also have to source rods, pins and pistons with shorter crown height
It was still accelerating in pic, went 'off the clock' (on a slight downhill) probably only a mile or two.
That motor as already done multiple dyno runs with various carb and exhaust configurations (right up to major points 'bounce', around 12,500rpm)
I've posted dyno runs in build thread, power varied fron ~33 to 40 bhp ( for comparison, stock GS500 twin made around 36~38bhp, DRZ400SM, 36bhp)
Brendon is running 80+ for extended periods though (his speedo is running slow, thought it was 70~75)
dp9
Coast to Coast
frogman: go to know about the points area, I'll keep a look out.
PJ: I was thinking maybe an offset crank grind for an extra mm or 2. is the bore for the 378 dictated by the size of cheap available pistons?
damn, i dont think ive gotten mine above the low 90's. gatta find a hill, laugh. I'm still going to get the highway sprockets just to be on the safe side.
PJ: I was thinking maybe an offset crank grind for an extra mm or 2. is the bore for the 378 dictated by the size of cheap available pistons?
damn, i dont think ive gotten mine above the low 90's. gatta find a hill, laugh. I'm still going to get the highway sprockets just to be on the safe side.
