Oil analysis after new cylinder breakin

I just changed the mineral oil after 25 hours with new Superior Millenium
cylinders (standard cast). The rings are broken in and consumption has
stabilized. My analysis came back with high Lead, Chrome, and Nickel
levels which Superior says it normal with these cylinders. However, the
analysis also came back with very high levels of Tin (13.6 vs 1.2 before
the new cylinders). Aviation Laboratories said on the analysis sheet that
this could be caused by bearing wear. My A&P said the lower half of the
engine looked good when he installed the Cylinders. Superior says the Tin
shouldn't be in there from breaking in the cylinders. They suggest retesting
in another 25 hours.

Anyone know what may be going on with the Tin? Thanks in advance....


Trip Farmer
N8501N
PA28-235

I am thinking that the tin is coming from the white metal piston big end and
crankshaft support bearings.
You can easily draw your own conclusion what the eventual result will be.
If the bearings are stripping metal, for sure you will soon see a gradual
drop in oil pressure.
They may have been under increased strain from tight piston rings in new
cylinders as you broke in the new Millenniums.
How would your A&P know the bottom end "looked OK" if the bottom end was not
stripped and the parts checked for dimensional wear.
I would keep a very careful eye [and ear] on that engine until it has done
another 25 hours and results of another oil check are to hand.
Good luck with that one !

--
Roy
N5804F - PA28-181

"TripFarmer" wrote in message
...
I just changed the mineral oil after 25 hours with new Superior Millenium
cylinders (standard cast). The rings are broken in and consumption has
stabilized. My analysis came back with high Lead, Chrome, and Nickel
levels which Superior says it normal with these cylinders. However, the
analysis also came back with very high levels of Tin (13.6 vs 1.2 before
the new cylinders). Aviation Laboratories said on the analysis sheet that
this could be caused by bearing wear. My A&P said the lower half of the
engine looked good when he installed the Cylinders. Superior says the Tin
shouldn't be in there from breaking in the cylinders. They suggest
retesting
in another 25 hours.

Anyone know what may be going on with the Tin? Thanks in advance....


Trip Farmer
N8501N
PA28-235

I currently own 1/3 of this plane and am making an offer to buy the other 2/3.
Now I'm not sure if I should buy the other 2/3 or whether or not I should
sell my 1/3.


Trip


In article . net, says...

I am thinking that the tin is coming from the white metal piston big end and
crankshaft support bearings.
You can easily draw your own conclusion what the eventual result will be.
If the bearings are stripping metal, for sure you will soon see a gradual
drop in oil pressure.
They may have been under increased strain from tight piston rings in new
cylinders as you broke in the new Millenniums.
How would your A&P know the bottom end "looked OK" if the bottom end was not
stripped and the parts checked for dimensional wear.
I would keep a very careful eye [and ear] on that engine until it has done
another 25 hours and results of another oil check are to hand.
Good luck with that one !

--
Roy
N5804F - PA28-181

"TripFarmer" wrote in message
...
I just changed the mineral oil after 25 hours with new Superior Millenium
cylinders (standard cast). The rings are broken in and consumption has
stabilized. My analysis came back with high Lead, Chrome, and Nickel
levels which Superior says it normal with these cylinders. However, the
analysis also came back with very high levels of Tin (13.6 vs 1.2 before
the new cylinders). Aviation Laboratories said on the analysis sheet that
this could be caused by bearing wear. My A&P said the lower half of the
engine looked good when he installed the Cylinders. Superior says the Tin
shouldn't be in there from breaking in the cylinders. They suggest
retesting
in another 25 hours.

Anyone know what may be going on with the Tin? Thanks in advance....


Trip Farmer
N8501N
PA28-235

Do you have a full flow oil filter (I hope so!)? Otherwise break-in
steel from the cylinders could be scratching in the bearings.

I would think it strange that a bearing would fail just because you
changed one or more cylinders. Increased loading from new jugs sure
isn't going to cause it.

wrote:
: Do you have a full flow oil filter (I hope so!)? Otherwise break-in
: steel from the cylinders could be scratching in the bearings.

: I would think it strange that a bearing would fail just because you
: changed one or more cylinders. Increased loading from new jugs sure
: isn't going to cause it.

Perhaps a cylinder isn't on exactly perpendicular to the crank and it's
side-loading a big-end bearing? Are the base O-rings pooched out somehow,
or is there paint around the cylinder base nuts?
--
Aaron Coolidge

Yes we have a filter. Still can't figure out the reason for higher
tin levels.

Trip

In article , says...

Do you have a full flow oil filter (I hope so!)? Otherwise break-in
steel from the cylinders could be scratching in the bearings.

I would think it strange that a bearing would fail just because you
changed one or more cylinders. Increased loading from new jugs sure
isn't going to cause it.

I'm not sure about the O-rings or paint...........


Trip

In article , says...

wrote:
: Do you have a full flow oil filter (I hope so!)? Otherwise break-in
: steel from the cylinders could be scratching in the bearings.

: I would think it strange that a bearing would fail just because you
: changed one or more cylinders. Increased loading from new jugs sure
: isn't going to cause it.

Perhaps a cylinder isn't on exactly perpendicular to the crank and it's
side-loading a big-end bearing? Are the base O-rings pooched out somehow,
or is there paint around the cylinder base nuts?
--
Aaron Coolidge

In article , (TripFarmer)
writes:

Yes we have a filter. Still can't figure out the reason for higher
tin levels.


The trouble shooting guide from Cleve Tech Center re oil analysis says:

TIN (Sn)

Origin Bearings, Pistons

Purpose Tin is a conforming material used to plate and protect surfaces to
facilitate break-in.

Maybe there is no problem with tin during the break-in.

Chuck