Topic: Oil starvation to part of camshaft. Blocked oil supply passage?

[disco]

They will fail fast... 15 minutes run time and a couple miles riding was all it took for one of mine to end up like Ekpent s

Wow! Good to know.

[PeWe]

sure it was the nut that came loos or the stud coming up from the head? Might be time for tread insert if threads are bad

[jonda500]

I was only 5 minutes from home (very lucky!) when my chirping noise started, but I still wrecked the rockers and cam lobes on that side... when I get around to taking it apart fully I will post what I find out about what blocked the oil supply on that side - I suspect that somehow something got in there when I changed the oil filter (half an hour before it happened).
John

[Mr. Clutch]

OK, I FINALLY got a chance to open my engine up. There is widespread devastation on the far right side of the camshaft. The journal bearing surface and cap are really chewed up. Also, the cam lobes on that end of the camshaft are extremely worn.

There's so much metal debris pooled on top of the head I'm surprised it ran at all!

[Mr. Clutch]

Busy day.

So while I'm in here I figured I'd split the cases to clean up the bottom end and replace the primary chains and tensioner.

In the meantime I want to get the cylinders honed and a valve job with new valve guides. I'm having trouble finding a shop in the Detroit Metro area that is equipped or willing to do the work. And I thought this was Motor City!

Does any body know a good shop for this?

[seanbarney41]

Excellent mc specific machine shop here in Kalamazoo...perhaps you have other business in the area and could kill 2 birds with one stone?

[Mr. Clutch]

Well I found one machine shop that may be able to do the valve job but I they don't know if they have the fixturing to hold the head. They mainly specialize in high-performance Big Three engines but have been known to do old Harley heads from time to time.

I tried most of the bike shops around here. The Harley shops want nothing to do with it. The dealer service centers tell me it's too old and the shop I used to use that worked on old Japanese bikes recently switched to custom work only.

I'm thinking about sending my head off to CycleX in Wisconsin. I hear they have a great mail-in machining program.

[seanbarney41]

that is another good option

[pjlogue]

  You did mention in an earlier post that the nut on the cam tower bearing stud was loose. If indeed that bearing shell was loose fitting on the cam it could create an oil film failure resulting in a burn out.

Hmm, that's right, there was a nut on one of the cam towers that was completely loose. I could see a breakdown in the oil film of this journal causing the debris I found in the oiling hole of that cam shell, but do you think it could explain the lack of oil to that end of the camshaft?

Here's a few pictures. The oil on the cylinder 4 cam lobes and rockers are from me adding a few drops to confirm that was the contact area causing the chirp. When I first opened it up it was completely dry beyond the lobes of cylinder 3.

If it was a bolt/nut holding the cam carrier to the head then it could cause oil starvation to the cam.  Oil would squirt out between the head and the cam carrier.  What bolt/nut was lose in relation to the bad journal?

-P.

[Mr. Clutch]

If it was a bolt/nut holding the cam carrier to the head then it could cause oil starvation to the cam.  Oil would squirt out between the head and the cam carrier.  What bolt/nut was lose in relation to the bad journal?

-P.

It was the nut on the failed journal that was loose. The bolt on that same journal was still tight.

I guess the question is what happened first? Did the nut backing out cause a loss in oil pressure to the journal or did a loss of oil pressure create enough friction and wear to work out that nut?

[Kevin D]

American Wings is on Michigan Avenue in Wayne. I have been in there once or twice, but I never had any work done there. It is a decent sized shop and has been around for at least 10 years.
The Doctor of Hondas in Waterford closed their doors recently.

http://www.motorcyclerepairmichigan.com/services.html

[PeWe]

Check if stud is creeping up from the head. A small radius of alu from head up around the stud where it enters the head is a bad sign. If it is like that inspect all 4 studs since they might been over torqued.

[ekpent]

Pull out the little oil jet with the rubber ring to see if it is plugged. If it wasn't though it may be now with metal now. Any sign of silicone sealent bits in the pan or around side covers etc..

[MRieck]

I'd disassemble and clean out the oil pump too.

[Mr. Clutch]

I checked the stud in question (see image attached) and I can't see any evidence that it has backed out. All four studs are roughly 45.25 +/-0.2 mm long when measured from tip to cylinder head, which seems reasonable to me.

I pulled out both oil jets and wouldn't you know it, one is plugged up pretty good. The trouble is, I'd swear the plugged jet is from the OTHER side of the head. But it is possible I accidentally laid them out in the opposite spots when disassembling it yesterday so I can't say for certain.

Is it also possible for the oil passage through the cam carriers to become blocked? It's just a little strange that the far journal on that carrier was completely starved yet the journal nearest to the oil jet seems to have been relatively unaffected.

[Mr. Clutch]

Also, there is evidence that this engine was apart before.

First I noticed a few fins on the jugs were bent up as if they had been pounded on before. One fin broke off when pulling the jugs (oops) so I'll need to JB Weld it back on. Second, the loose nut was a little suspicious to me but with all the damage on that journal it wasn't out of the question.

But the smoking gun was a missing washer under one of the cylinder head nuts. That shattered my confidence in the last rebuilder.

[Mr. Clutch]

American Wings is on Michigan Avenue in Wayne. I have been in there once or twice, but I never had any work done there. It is a decent sized shop and has been around for at least 10 years.
The Doctor of Hondas in Waterford closed their doors recently.

http://www.motorcyclerepairmichigan.com/services.html

I just called American Wings and they recommended I try Stoney Creek Motorsports down in Belleville. They're closed on weekends so I guess I'll call on Monday.

[seanbarney41]

Were orings at the outer ends underneath cam towers​ present?   These are at the end of the oil passage and also can cause cam failure if not present and often left out by sloppy rebuilders

[Mr. Clutch]

Yes, both outer O-rings were present.

The O-ring on the failed side was stuck to the bottom of the carrier while the other remained in the recess on the head. Is this normal or might this suggest the O-ring wasn't seated properly?

[seanbarney41]

Totally normal

[700504]

Did any threads come out with your cam carrier or cam bearing bolts? I've had these be stripped and cause oil starvation, the threads are so brittle and only require 7ft/lbs torque. I've had to helicoil many of them.

[Mr. Clutch]

Surprisingly no threads were damaged. I'm leaning towards that nut not being torqued down properly. Or not at all!

[Mr. Clutch]

This past weekend I've made plenty of progress in tearing down my engine.

I took the jugs and the head to Stoney Creek Motor Sports. It's one of those old school engine shops run by an old school guy. My type of place.

It took me two days and almost an entire bottle of propane to bust those blasted JIS case screws loose. They had obviously been knackered before by my least favorite engine builder, probably using the incorrect screwdriver. Good thing I have SS Allen Head replacements.

Also of note, after pulling off the covers I saw the distinctive orange tint of Silicon RTV oozing from between the cases. Some people just want to watch the world burn...

The last thing I have to remove before splitting the cases is the bearing retainer on the left side of the transmission but those pesky cross-head screws are sure putting up a fight. Is it necessary to remove this bearing retainer to split the cases?

I'm only asking because the manual also says to pull the rotor but I know that isn't required.

[Kevin D]

Do you not have an impact screwdriver? It is the key to getting the phillips screws out.
I have read stories where guys have drilled the screw heads off after buggering the Phillips.
 Yes that bearing holder should come off and yes the screws are tough because they are staked in place.

[Mr. Clutch]

I have a pretty nifty impact screwdriver in JIS #3 from Vessel.

So far the screws on the bearing retainer don't want to budge. I'll just have to be more persuasive.