Metal shavings in oil after first 100 miles

ag12680 · Mar 12, 2016

Here is what I've found in the sump screen which looked like fiber but flocked to the magnet except for a few aluminum bits shown in the beaker.

Bike is not smoking nor did it use any oil. Top end was rebuilt with new rings and a bore hone. Bottom end left alone though the motor had not run for 32 years with 7,800 original miles. '75 MkIII

Seems like a lot of debris. Going to track down a bore scope to look in the cylinders. Any ideas what this could be? Wrist pin circlip popped out?

Very disheartening after all the effort and expense to say the least.

Thanks,

Andy --

Metal shavings in oil after first 100 miles

Roadrash · Mar 12, 2016

Sitting for 32 years and not inspecting, cleaning, replacing and or lubricating all the moving parts in your bottom end is the first and most obvious reason for your problem. Stuff gets dry, hard and corroded sitting that long.

Roadrash · Mar 12, 2016

Not to sound like I'm scolding you friend, because we all feel your pain here. Besides bearings getting torn up from crud there is also vital plumbing that could be clogged.
Pull the motor again, split the cases and do a proper rebuild.

Biscuit · Mar 12, 2016

It's kind of hard to say what that is. If mine I would give it another oil change interval before jumping to conclusions. Very small filings that may have been in there for a while will grab onto sludge that may also have been in there for a while and "bulk up" what's on the magnet. The other stuff, hard to tell. Being a MK3, and their reputation for soft cams, it could be cam and follower damage. Particularly if you did not oil up the lobes and followers before assembly and also if you let it idle at a low RPM after initial start-up.

dynodave · Mar 12, 2016

Bike is not smoking nor did it use any oil. Top end was rebuilt with new rings and a bore hone. Bottom end left alone though the motor had not run for 32 years with 7,800 original miles. '75 MkIII

Biscuit said:
snip Being a MK3, and their reputation for soft cams, it could be cam and follower damage. .

I would normally say it is brain dead to have a MKIII and do "rings/top end" and NOT SPLIT THE CASES to pull out the original garbage MKIII cam . I have diagnosed well over a dozen LOW mileage MKIII with dead cams. I know Jim C will jump in and say HIS ran to high mileage, but to be sure, the percentages I have been involved with are not on his side. I have NEVER NEVER NEVER found one to have a hard cam (and I've tested many) in spite of all preceding commando's measuring in the high 50's RC. I just did one the other day and it was a wopping 28RC...the highest I have ever seen in a MKIII.
My five mile, factory new, never registered MKIII will have a NEW NOS cam in it before I drive it. (sorry to sound like BDM).

comnoz · Mar 12, 2016

Well, I am rebuilding a MK3 right now with the original cam. It is over 100,000 miles.

And yes it will get a new cam although the cam that is still in the engine looks pretty good yet.

I am sure it is "soft" but obviously it was run with the right lubricant. Jim

ag12680 · Mar 12, 2016

Motor sat with oil during those years which I drained and inspected with no sludge in the trap.

Inspected the cam lobes and even posted photos here showing that they were not showing undue wear.

Lubed on assembly and poured oil in the galleys before starting. Kept the revs up on initial start though it did idle during the 100 miles.

First, would you agree that this is an usually high level of metal?

Second, is this what metal from a soft cam would look like?

Yes, in hindsight the bottom end should have come apart.

Thanks,

Andy

comnoz · Mar 12, 2016

ag12680 said:
Motor sat with oil during those years which I drained and inspected with no sludge in the trap.

Inspected the cam lobes and even posted photos here showing that they were not showing undue wear.

Lubed on assembly and poured oil in the galleys before starting. Kept the revs up on initial start though it did idle during the 100 miles.

First, would you agree that this is an usually high level of metal?

Second, is this what metal from a soft cam would look like?

Yes, in hindsight the bottom end should have come apart.

Thanks,

Andy

No, I would not call that an undue amount of metal. Clean it out and ride it.
Look at again in a couple hundred miles. If the cam were failing you would have a lot of very fine metal.
Once a cam begins to fail it will go from good to flat in a hundred miles or less. You will know it. Jim

Torontonian · Mar 13, 2016

Everything there looks acceptable to me for wear. Since the barrels were off , did you even look at the cam lobes. very easy to do.

ag12680 · Mar 13, 2016

Thanks Jim... Appreciate your advice.

Here are the cam shots previously posted:

comnoz · Mar 13, 2016

ag12680 said:
Thanks Jim... Appreciate your advice.

Here are the cam shots previously posted:

Well it's hard to say for sure from a picture, but if that is a divot from a piece of metal that is missing from the top of the lobe in the first picture then you better be doing something about it.

But if it's just a piece of foreign material stuck to the lobe then no problem. Jim

ag12680 · Mar 13, 2016

Jim -

I think this is a piece of lint causing a reflection from the oil it picked up. When I rolled the cam over I remember checking the tops of the lobes closely because I'd heard about the soft cam issue here on the forum.

Which cam do you replace the stock item with if I end up tearing it apart again?

Thanks much,

Andy

petejohno · Mar 14, 2016

Check you tappet clearances. Any wear in the cam should be evident tbere. I had my original cam tuffrided. Just do an oil change with maybe a straight 50w and see how it goes b4 pulling it apart.

SteveBorland · Mar 14, 2016

I do not think you can detect a soft, wearing cam from the tappet clearances - the base circle does not seem to wear at all, it's the top of the lobes that goes.
On my 850 cam, only the inlet lobes were worn. I notice that the cam followers were installed wrongly, i.e. one follower with the chamfer forwards, the other to the rear. I do not know which follower was reversed, but I wonder if it was the inlet followers that were wrongly installed, could this have caused oil starvation on the inlet lobes?

It just seems odd that there should be a difference in hardness between lobes. I always thought the cam was hardened as a unit.

Bernhard · Mar 14, 2016

I can understand your alarm signals going off, but as stated elsewhere it is hard to tell if it came from anywhere in the engine if there is no noticeable difference in performance- oil has to be kept clean when in the engine or the swarf you may have in there can be pumped around without any idea of the owner.
You have to decide if you want to strip this engine or alternately just fill it up with oil and 100 miles later drain the oil and see if any more debris pops up from somewhere.
If the latter, I suggest you fit a magnetic sump plug that are available from Norton.

comnoz · Mar 14, 2016

SteveBorland said:
I do not think you can detect a soft, wearing cam from the tappet clearances - the base circle does not seem to wear at all, it's the top of the lobes that goes.
On my 850 cam, only the inlet lobes were worn. I notice that the cam followers were installed wrongly, i.e. one follower with the chamfer forwards, the other to the rear. I do not know which follower was reversed, but I wonder if it was the inlet followers that were wrongly installed, could this have caused oil starvation on the inlet lobes?

It just seems odd that there should be a difference in hardness between lobes. I always thought the cam was hardened as a unit.

The pre-75 cams are case hardened. There is no way there could be a difference in the hardness of different lobes on the same cam. The only way of keeping one lobe from being carborized and hardened with the other three would be to copper coat it.

Being a cam distributor I see a lot of cams that are returned as cores. I see the same types of failures among the hard cams as I do the softer MK3 cams.

The last batch of cores I sent were 7 case hardened cams with one or mare flattened lobes, 2 MK3 cams and 1 Megacycle cam all with similar lobe failures.

I will say it again -the oil compatibility has more to do with the life of a cam than the hardness of a cam. Jim

worntorn · Mar 14, 2016

As in oil with a high ZDDP count, or are there other factors as well to look for?

I've been using VR1 racing oil as it has a high ZDDP count and always seems to fare well in wear testing. It's not overly expensive and normally stocked at Napa, so easy to find. Hopefully it will do the job. They even offer monograde 50 weight if you like that viscosity for hot weather riding.

Glen

comnoz · Mar 14, 2016

ag12680 said:
Jim -

I think this is a piece of lint causing a reflection from the oil it picked up. When I rolled the cam over I remember checking the tops of the lobes closely because I'd heard about the soft cam issue here on the forum.

Which cam do you replace the stock item with if I end up tearing it apart again?

Thanks much,

Andy

Andy,
If you end up needing a cam then I would recommend a Webcam #312. I normally have them in stock.

If that is just a piece of crud stuck to the cam then you probably don't have anything to worry about.

Just make sure you use an oil that is suitable for a hot running, flat tappet engine.

Use a motorcycle specific oil or a heavy duty diesel oil. Not lighter than 20-50 for warm weather.

If the oil is approved for use in a late model pollution controlled car then it does not contain the additives needed to keep a Norton cam intact. Those additives would foul the catalytic converter. Jim

JimC · Mar 14, 2016

I will say it again -the oil compatibility has more to do with the life of a cam than the hardness of a cam.

The gal who owns Web Cams said the same thing to me a few years ago.

comnoz · Mar 14, 2016

worntorn said:
As in oil with a high ZDDP count, or are there other factors as well to look for?

I've been using VR1 racing oil as it has a high ZDDP count and always seems to fare well in wear testing. It's not overly expensive and normally stocked at Napa, so easy to find. Hopefully it will do the job. They even offer monograde 50 weight if you like that viscosity for hot weather riding.

Glen

Racing oils are generally going to have the correct additives -as long as they are not approved for use in pollution controlled street cars.. What they may lack is a long lasting detergent package so they may need to be changed more often.

ZDDP is only one of the additives seen in heavy duty motor oils.

Also necessary is a heavy grade base stock so it does not have to be pumped up with VI additives. Vi additives do not last long in the high temp environment inside a Norton head. Jim

Metal shavings in oil after first 100 miles

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