Tin in UOA?

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Just hoping I could get some feedback on this - had a few UoAs on the Mini, but just recently had one come back that had some tin in it - never had it before. Just wondering if this is something to look into, or if it's related to the oil itself? (all oils had minimum of 50-60 autox runs on them)
 
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MolaKule

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Tin is sometimes used as a bearing coatings and/or bearing alloys. Z-ROD has no tin in it's formulation. Even with the autocrosses you have done, the overall wear values are quite good.
 
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Lead and Tin are normally used together as an overlay on leaded bronze bearings. But there is no Lead in the sample. Probably not a problem.
 
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Tin usually increases if the oil is too thick or run too long that it thins out. In your case it may be the former. What was the viscosity of the last oil run in the middle column?
 
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Tin is the primary ingredient in babbit, which is the metal your crankshaft touches in the main bearings. Babbitt name ASTM B23 / QQ-T-390 Lead % Tin % Antimony % Copper % Number 1 Grade 1 0% 90-92% 4-5% 4-5% RotoNickel -.15% Monel Grade 2 0% 88-90% 7-8% 3-4% Super Tough Grade 3 0% 83-85% 7.5-8.5% 7.5-8.5% Grade 11 (SAE-11) Grade 11 0% 86-89% 6-7.5% 5-6.5% Copper Hard Grade 6 + 50-52% 35-37% 11-13% 0.5-1.5% Formula 0 Heavy Pressure Grade 7 74-76% 9.3-10.7% 14-16% 0% Number 4 Hardware - 84-86% 1-2% 12-14% 0% Grade 13 Grade 13 83-85% 5.5-6.5% 9.5-10.5% 0% Merit Babbitt 73-75% 9-10% 15-17% 0% Royal Grade 8 79-81% 4.5-5.5% 14-16% 0%
 
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I'd not get too concerned over a one-off appearance of a tiny proportion of tin. If it continues or gets worse, it might be time to start considering what might be wrong. OT, what's so special about this oil? I can't see anything special in the add pack. Why not just run M1 0W-40, an oil with all of the important certs that would also cost less and call it a day?
 

kyoo

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Originally Posted By: deven
Tin usually increases if the oil is too thick or run too long that it thins out. In your case it may be the former. What was the viscosity of the last oil run in the middle column?
gotcha. first oil is the OEM 5w30, second oil is Pennzoil Ultra 5w30, and third is Amsoil ZROD 10w30. It's interesting how much variance there is.
Originally Posted By: leeharvey418
Thirded - tin is commonly found in bearings.
Thanks for the info
Originally Posted By: A_Harman
Lead and Tin are normally used together as an overlay on leaded bronze bearings. But there is no Lead in the sample. Probably not a problem.
Thanks for the info
Originally Posted By: MolaKule
Tin is sometimes used as a bearing coatings and/or bearing alloys. Z-ROD has no tin in it's formulation. Even with the autocrosses you have done, the overall wear values are quite good.
Thanks for the info. Thanks, I think the oil did okay for the number of runs I did on it.
Originally Posted By: fdcg27
I'd not get too concerned over a one-off appearance of a tiny proportion of tin. If it continues or gets worse, it might be time to start considering what might be wrong. OT, what's so special about this oil? I can't see anything special in the add pack. Why not just run M1 0W-40, an oil with all of the important certs that would also cost less and call it a day?
Thanks, I'll definitely continue to monitor. Just thought it was odd that it suddenly showed up. Maybe the motor doesn't like the oil? I'm actually in the process of testing a bunch of oils for the Mini. This was just one of them. This is supposedly quite good for the Evo, which does a lot of (1) sitting for long periods of time and then (2) run pretty hard at autox & is turbo. I have a list of a few others I'll be testing for next season, I just don't drive the car all that often except for racing.
 
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With a copper count of 5, I would think the tin count of 3 is from a tiny amount of wear of a bronze component (I would guess something in the valvetrain?). Lead is 0. Iron of 11 could be better ... but the engine is till new and you are likely running this thing kinda hard. This is a good UAO, though, considering the hard use.
 

kyoo

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Interesting, thanks for the input. I'll be continually keeping on eye on things. Just FYI for anyone who's unfamiliar, autox is ~40-60s runs from courses made of cones in parking lots. You don't typically go above 60mph. 83 runs (last oil) is about 14 events worth of autox. Most people do 5-10/yr max. I've done ~30 this year
 
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