Author Topic: Top End oiling Issues  (Read 2673 times)

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Offline Dave Wyatt

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Top End oiling Issues
« on: July 13, 2011, 12:05:18 pm »
I finally broke down and replaced the head studs in my 'matic.  Used the slightly larger aftermarket parts as was suggested.  After getting the bike back together and running it very little, I started hearing a squealing noise from the top end.  Turns out, the far right cam journal was dry, and I had ate up the camshaft and the base. 

Sourced a replacement cam and base, got it back together, and all seemed well.  At least until I got a few miles from home.  Sure enough the engine was slowing down, the top end was hotter than hell, and it finally stopped running when I neared the house.

That was in 2009.  Since then it has been sitting with the battery tender hooked up, but otherwise ignored.  My new Goldwing has been getting the attention since then.  But now my son has expressed interest, and I finally have some time, so I tore into it today.

Three cam journals nuked!  Something tells me the stud upgrade and my oiling issues are related.  Now I just have to figure out what is going, or not going, on inside the engine.  I pulled the rocker cover and spark plugs, removed the caps on the cam journals, and cranked her over.  The oil pressure light goes out quickly, the engine spins good, but no oil appears on the top end.  After cranking it takes a few seconds for the oil light to light up.

Can anyone tell me how the oil is routed to the top end from the pump?  I'm guessing I managed to plug something up, but I need to know where to start looking.

Not looking forward to pulling the engine out again :o
Dave Wyatt
1976 CB750A
1965 C100
2008 GL1800
I swear, the damn things are starting to breed!

Offline MCRider

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Re: Top End oiling Issues
« Reply #1 on: July 13, 2011, 12:30:26 pm »
This is a relatively common issue as catastrophes go. It is most likely NOT the stud upgrade. Tens of thousands of stud upgrades have been installed in engines that really need their oil, and no problems.

I have twisted a cam as have many others on the forum. That's the coolest manifestation of the problem. One side goes dry, seizes the cam in the bearing and it twists in half. The engine will continue running on the other two cylinders! leaving you with some cool souvenirs.

It occurs almost exclusively after a rebuild and the cause is almost exclusively the use of a silicone gasket sealer. The silicone squishes out both the external and the INTERNAL part of the seam. It will then harden and flake off. It will then travel thru the oil system like a blood clot waiting for the most restrictive area of the blood er oil system in which to lodge itself. That happens to be the oil orifice under one or the other (or both?) cam bearing block.

When fixing you almost have to remove the head and be dang sure that orifice is clear. You can clear it with a fine wire from the top but you don't know for sure if the silicone chip (it can be other debris, but usually silicone) has fallen all the way into the sump where it can be removed from the pan...or not.

(I don't even know if that's possible, for it to fall down to the sump. Maybe not.)
« Last Edit: July 13, 2011, 12:53:11 pm by MCRider »
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline raymond10078

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Re: Top End oiling Issues
« Reply #2 on: July 13, 2011, 12:42:56 pm »
Hopefully this pic will upload.  It shows the path.  The "circle" around the valve spring is the orifice.

1978 CB750A (upgrading very, very slowly)

Past bikes - Honda: SL350, CX650C, CB900C, CB1000C, CM450A; Kawasaki: several 1972 750 H2's; Suzuki: TC90J.

Bikes I want: CX650ED, a mid-sized japanese V-twin with ABS.

Offline Dave Wyatt

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Re: Top End oiling Issues
« Reply #3 on: July 13, 2011, 12:59:16 pm »
Well, you just cleared that up.  I suspected debris. and that the oil traveled past the studs to get to the top end.  I did use silicone on the pesky disks under the cam base, some of that may have gotten in the way.

I'll try spinning the engine over after the cam and both bases are out, to check for oil flow before I pull the engine.  If I get good flow I'll likely not pull the engine and remove the head.
Dave Wyatt
1976 CB750A
1965 C100
2008 GL1800
I swear, the damn things are starting to breed!

Offline MCRider

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Re: Top End oiling Issues
« Reply #4 on: July 13, 2011, 01:24:21 pm »
Well, you just cleared that up.  I suspected debris. and that the oil traveled past the studs to get to the top end.  I did use silicone on the pesky disks under the cam base, some of that may have gotten in the way.

I'll try spinning the engine over after the cam and both bases are out, to check for oil flow before I pull the engine.  If I get good flow I'll likely not pull the engine and remove the head.
That should work. I'd pull the pan and clean it and the oil pump screen also. Don't ask me how I know.   ;)
Ride Safe:
Ron
1988 NT650 HawkGT;  1978 CB400 Hawk;  1975 CB750F -Free Bird; 1968 CB77 Super Hawk -Ticker;  Phaedrus 1972 CB750K2- Build Thread
"Sometimes the light's all shining on me, other times I can barely see, lately it appears to me, what a long, strange trip its been."

Offline jukku

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Re: Top End oiling Issues
« Reply #5 on: July 28, 2011, 11:20:03 am »
This happened to me twice on the same engine!
First time 2009 32 years after Honda assembled the engine >:(
Second time 2010 about 3000 miles after the topend job was done  :'(

Any ideas whe the o-ring failed this way?

Offline raymond10078

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Re: Top End oiling Issues
« Reply #6 on: July 28, 2011, 11:28:52 am »
I assume that the machined recess (that the o-ring goes into) is clean/clear.

I'm just wondering about o-ring material capatibility with oil.  Some materials are not oil friendy.  Did the o-rings swell? 
1978 CB750A (upgrading very, very slowly)

Past bikes - Honda: SL350, CX650C, CB900C, CB1000C, CM450A; Kawasaki: several 1972 750 H2's; Suzuki: TC90J.

Bikes I want: CX650ED, a mid-sized japanese V-twin with ABS.

Offline jukku

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Re: Top End oiling Issues
« Reply #7 on: July 28, 2011, 02:06:35 pm »
It looked clean and the recess was symmetric.
I cannot figure out how it could could move tovord the oilpressure :o
Let see next summer if it do it again. Probably not because I have changed the top end to a 836-set!

Offline raymond10078

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Re: Top End oiling Issues
« Reply #8 on: July 28, 2011, 04:41:18 pm »
Again, if you compare a used o-ring with a new o-ring, did the used one swell?  The point of my question is that an o-ring, if it were to swell, will "do what it takes" to fit in the available area.  Since the o-ring is always saturated with oil, if it were not compatible, it would easily move/shift when the bike is not running.  I've seen a number of materials swell due to incompatability.  I have a hard time believing this is your situation, but it the only thing I can imagine.  I'd hope that your parts vendor is selling you the right parts.

Do a google search for "o-ring swelling oil".  Lots of info out there.
1978 CB750A (upgrading very, very slowly)

Past bikes - Honda: SL350, CX650C, CB900C, CB1000C, CM450A; Kawasaki: several 1972 750 H2's; Suzuki: TC90J.

Bikes I want: CX650ED, a mid-sized japanese V-twin with ABS.