Oil Analysis

#1

I know oil has been beat to death on this and other websites, but I feel inclined to share my recent oil analysis results. The engine has 21 hours since rebuild and 13 hours on Mobile 1 15W-50 EP. I would be interested in hearing all comments and comparing results with others. Please post your results if you have them.

#2

FishMan wrote:

Fish got my comments off line. That being said…the trouble with oil analysis is that we don’t put our best foot forward. OA is best at showing trends. But to do that you have to have multiple samples and good documentation. It’s hard to take one sample in isolation and get interpretations that can be relied on.

In isolation (meaning no history of analysis to compare to) all you really can tell is whether or not the oil’s additive package was what it should have been. For example, I tried Valvoline Premium Blue last year because a article I read made it sound like thiss diesel oil a good inexpensive solution. But the oil analysis indicated that it’s additive package was not that great. What happened is that Valvoline had changed it’s additive package after the article was written, in order to gain a later certification. So the oil I had read about was not the same oil that I bought.

I’ve gotten 3 oil analysis. All of them with different engines and all with different oils. So I can’t really compare anything. The way to do this right is to take an oil sample after 10hrs and pay the extra for the TBN. That will tell you how much life is left in the oil. Once TBN has lost 50%, change the oil. Then get a sample from every oil load and watch the trends that develop.

#3

The report looks normal to me. It is also one of the rare reports that I agree with the Blackstone lab technician’s discussion points and recommendation. I have read hundreds of oil analysis reports over the years and have seen many inconsistent recommendations by Blackstone technicians. This one looks good.

I second Ranger’s thoughts and have a couple of additional comments.

Oil analysis on race engines is best used to provide peace of mind that nothing unusual (like a bearing going, a piston ring breaking, or a head gasket issue leaching water into the oil) has happened. In this case, this reports shows all is well in this engine and Fish should have complete confidence wringing it’s neck the next time out.

The trouble with race oil analysis is that the oil is in the engine for a very short time. Thus, additive depletion usually is negligible unless one of the catastrophic events discused above allow excessive fuel or water in to dillute the oil. Water and/or fuel dillution can deplete the additive package quickly.

Finally, I am not sure I agree with Ranger about TBN for race applications. Ranger is correct that TBN (total base number) is an indicator of additive health and that a change in TBN is an indicator that the oil is loosing it’s ability to protect the engine. It is most widely used however, in extended drain interval applications where a small sample of oil is extracted for analysis and most of the oil is left in the sump for continued use(keep in mind many over the road trucks have 30qt sumps and changing the oil is very expensive). When the TBN starts dropping (say after 10000-15000 miles in a street engine) then it is time to start thinking about changing the oil. We typically change our race oil so frequently that we’ll never see a TBN drop.

Don

#4

Gents,

I appreciate the comments. At this last change, I switched to Amsoil Dominator Racing Oil 15W-50 in hopes of decreasing wear a bit. I’m hoping the silicon levels will be very low and the other metals will decrease a bit.

#5

Fish,

I use Amsoil 15W50 Dominator as well. Be sure to sample/drain the oil at the same interval you did the Mobil-1.

It will be interesting to see the differences.

Don

#6

Here is the following oil analysis, after running at Putnam Park and Road Atlanta (8 hours on engine). Metal content is still high and I’m starting to think I might need a baffle system in addition to my crank scraper. Then again, is it possible that racing our engines results in high metal numbers?

[file name=E26292.pdf size=18585]http://spece30.com/media/kunena/attachments/legacy/files/E26292.pdf[/file]