Help diagnosing source of copper in oil analysis

[xyz]

This has to do with a 2004 Mercruiser 496HO 425hp marine engine. The engine has been heavily modified by me over the years now is 625 hp. 382 hours on boat but last engine full rebuild was 152 hours ago. I have done an engine oil analysis every season since new. Never had a red flag show up till last year in the form of high copper (199 ppm) in the oil. This was discounted at the time because it was thought the source was copper oxides from the install of a new copper and bronze oil cooler. I am told that should have been a one time event. This season the copper has increased to 261 ppm. Previously I have seen season copper numbers of 16ppm (90 hrs),35ppm (80 hrs, installed new heads with bronze valve guides, new cam same bearings),10ppm (40 hrs new cam same bearings),13ppm (36 hr full engine rebuild including new bronze valve guides). My question: is the copper coming from the main bearings or other since the bearings are a copper and lead metal matrix (Clevite-77 'H')and no change in lead levels has shown up along with the increased copper?

The current oil is Mobil 1 15W50 sliver cap the last two seasons, Mobil 1 15w50 Gold Cap before that, then going back further Amsoil S2000 20W50 racing oil, Mobil 1 V Twim 20W50 and the Mercruiser OEM 20W40 oil.

 

[Trav]

Quote:
since the bearings are a copper and lead metal matrix (Clevite-77 'H')and no change in lead levels has shown up along with the increased copper?



With the lead being on top of the copper the lead would have to wear through before the copper would be exposed,i would think that lead levels would also be elevated.
My best guess would be the oil cooler is still shedding some copper.

 

[saaber1]

I wouldn't assume the oil cooler is a one time event. If the higher copper levels started after the oil cooler installation and no other metals are out of the ordinary it is logical that it is the oil cooler. I have noticed that some cars show elevated Cu levels due to oil cooler for a very long time. 2 cents...

 

[TC33]

xwz, Just wondering what oil cooler you used?? During my Mercruiser engine build, I replaced my factory cooler with a thermostatically controlled unit from Hardin Marine. Im sure someone builds them for them but I dont know who. I have never done an OA on my boat oil but am now considering it. I also used Mobil 1 15w50 gold cap until they stopped putting it gallon jugs and have been using silver cap since. Break in oil was Valvoline 40 weight. Engine is a 496 (stroked 454) and is in the 600HP range.

 

[xyz]

Tray, the bearing material is a matrix of copper and lead ie a mixture and not a layer of lead and a layer of copper.

I used the Hardin Marine 3x18 thermostaticily controlled oil cooler. The initial comment form Blackstone on the cooler was that the new copper/bronze interior would have some copper oxide present because it was exposed to the air (oxygen)that would cause the oxidation of the copper = copper oxide. But after the oil is present the air/oxygen is no longer there to react with the copper therefore no more copper oxide would develope. An additional in depth dicussion with Blackstone tech revealed that some Duramax engines , they have a copper oil cooler. have had high levels of copper as an ongoing issue. Anecdotal evidence is that certain oils and high oil temperatures may be the cause....but that is not confirmed. Blackstone did say since I disturbed the copper coated valve spring shims when I changed the valve springs is a real possibility because I did that while the last oil was sill in the engine. Clevite will, I hope, advise what is the ratio of lead to copper in the metal matrix which could confirm that the bearings are not involved if the lead % is significant.

 

[spasm3]

Don't the cam bearings have a lot of copper in them? some times this shows up in car engines for the first 10,000 miles. I'm not sure how marine hours compare with miles.

 

[Trav]

interesting i have never seen these bearings,i thought the Clevite 77 was a triple layer bearing.Do you have any more info on these?
I have seen copper lead matrix in diesel engines but even these had some sort of overlay usually babbitt for particle embedability,i have seen tin overlay also in some diesels.
I have never seen just a steel back with copper lead matrix and no overlay at all.If you get some more info please post it.

In any case i would suspect that the other element would also show a rise in the UOA.

 

[Mokanic]

Man the oil cooler will leach for a long time to come if there's alot of cooper in it. Your readings are not that high. Some oil chemistries seem to cause copper to leach worse than others but even then it ain't nothing to loose a seconds sleep over.

 

[mechtech2]

I doubt any one of us would have guessed that you
had copper plated shims in that engine [from the first post]!

So they, the oil cooler, or the bearings that are worn down to the lead/copper alloy [past the surface babbit material in the 77 H bearing]could be the source.

I think it's the oil cooler at this point.

 

[xyz]

Yes the Clevite 77 bearings have a flash top coating of tin except for the thrust surfaces where it is machined away.

 

[xyz]

Mokanic, your "Man the oil cooler will leach for a long time to come if there's alot of cooper in it. Your readings are not that high. Some oil chemistries seem to cause copper to leach worse than others but even then it ain't nothing to loose a seconds sleep over." is the news (the best news)that I have been waiting for.

This cooler was a shelf warmer at some boat dealer that they decided to get rid of. I found it on ebay. It was heavily heavily oxidized on the exterior which I cleaned up and painted. The fittings all had the plastic plugs but some significant level of interior oxidation could be expected ( based on the exterior condition) to be present in the inside (100% copper tubing & bronze casting). Blackstone labs also said that copper oxide disolved in the oil is no problem and can be leached by some oils. I am only concerned if the copper is from an excessive wear problem like from thrust bearings, etc.

 

[xyz]

I doubt any one of us would have guessed that you
had copper plated shims in that engine [from the first post]!

I appologize for the early omission but actually I forgot about them until someone asked if the shims were copper coated so I updated this post.

Thanks for your vote that the oil cooler as the source. I hope you guys are correct. That would be the best.

 

[xyz]

Originally Posted By: Mokanic
Some oil chemistries seem to cause copper to leach worse than others


Do you have a handle on what in the oil chemistries cause copper to leach more?

 

[mechtech2]

BTW, 625 HP should get you to your favorite fishing hot spot in a rapid manner!

 

[xyz]

Originally Posted By: mechtech2
BTW, 625 HP should get you to your favorite fishing hot spot in a rapid manner!


Yes but all my fishing gear is in the Champion bass boat (only 175 hp OB and 63 mph MAX). So a little longer to the hot spot if I am fishing.

 

[Kestas]

Your typical journal bearing for engines are made of copper powder placed on a backing of plain carbon steel, sintered, then infiltrated with lead and electrocoated with tin.

If they are wearing, that means you should initially get high tin levels, then get high copper and lead levels that are in a constant ratio.

 

[Steve S]

Rollercam? what is the thrust bushibg made from in that engine?

 

[xyz]

Update of the copper in the engine oil analysis: 2009=199ppm, 2010=261ppm, 2011=181 & 2012=203ppm. All with the Mobil 1 15W50 silver cap.