High lead content in my oil analysis?

[TowDawg]

I've taken apart and put back together most everything on the car by now, but I have not been inside the engine myself, so I need some help from you more experienced guys.
I send an oil sample to Blackstone Labs at each oil change and I have a concern that I'm hoping someone can help me with.
I had gotten a high lead result two times ago, but it was also after I had been at the track and running a roughly 50/50 mix of 93 unleaded and 112 leaded race fuel, so I (nor the guys at Blackstone) were too concerned about it. I only put 2k on the car since then with 2 more weekends at the track. The first weekend, I was running the 0W-40 I always had, and ran mostly leaded 112 as usual. After that weekend, I decided to switch to 15W50, so I did a drain and fill, but did not change the filter since there had only been about 500 miles since my last oil change. After 1.5k more miles and another track weekend, where I did NOT run any leaded fuel (pumps were broken, so only 93 straight from the local gas station), I just did a complete oil change and sent off the sample. By the way, the car is tuned for 93, but I run the mix just as extra insurance against detonation, so running just 93 should not be causing any issues. The car also ran just fine with no hint of detonation or hesitations. I got the results yesterday and I still have a very high lead content. Since there shouldn't be near the amount of lead from fuel, I'm getting a little concerned.
In our engines, what is made of lead, that if it were wearing, would cause the lead content to be high in the oil analysis?

 

[Tail lights]

Main and rod bearings

 

[Viper Specialty]

If the engine is all stock, there is no lead to speak of contained. Viper bearings, except for 2008+ Rod Bearings, are aluminum and do not contain a babbit layer which would contain lead.

 

[TowDawg]

Thanks Dan.
Aluminum readings have been consistent and are not high. Since I just bought a track car, the Viper will only being going to the NARRA event at Road Atlanta each year, so the track usage is going to go way down. I'll just keep an eye on future levels and hopefully see the lead start coming down.

 

[Tail lights]

Thanks for the correction Dan, you are so right, I was thinking old school. Those newer bearings are rock hard. They seem to be harder than the crankshaft serface.

 

[Viper Specialty]

Thanks for the correction Dan, you are so right, I was thinking old school. Those newer bearings are rock hard. They seem to be harder than the crankshaft serface.

Yes and no. Aluminum bearings are harder than the babbit layer of tri-metal bearings, and more immune to corrosion damage [not a problem these days] but are actually softer overall. One of the problems with aluminum bearings for connecting rod use [but ideal for mains] is that they can get "beat out" over time in high power applications because the aluminum layer is quite thick. Tri-metal bearings do not tend to do this. Its a toss-up. Aluminum offers better embeddability, but tri-metal offers higher strength. IMO, Aluminum Mains and Tri-Metal Rods are the ideal configuration.

 

[Allan]

So................where's the lead from? ........besides, maybe the foot.