[Supras] First oil analysis: high lead

[Michael Bringle]

For comparison here were my oil analysis's...
http://www.cygnusx1.net/Supra/TechTips/blackstone_lab.aspx


-Mike
http://www.CygnusX1.net/Supra


-----Original Message-----
From: supras-bounces at supras.com [mailto:supras-bounces at supras.com] On Behalf
Of joe at wilmcd.com
Sent: Friday, November 30, 2007 4:23 AM
To: supras at supras.com
Subject: Re: [Supras] First oil analysis: high lead

I can see the oil analysis is showing something, but is there a problem
you are trying to solve? What made you decide to do an oil analysis?

>From what I can tell from the other posts... it drives well, right? Don't
go looking for problems :-)

-Joe


> Just got results of my first oil analysis and found that a lead content
> of about 43 PPM was reported, whereas the norm is about 4.  Blackstone
> Labs attributed it to break-in wear, but I used the same main and rod
> bearings as the 35K mile (?) engine had since they were in good shape
> with about .002" clearance.
>
>
> I did "refinish" the cam bearing caps because of the wear, as I had
> written about before.  Cams in the head are not the ones which were in
> it originally.  I'm starting to think the soft coating on the cam
> journals was responsible for the high lead content, as it must have worn
> off to some extent.  If all of the lead had wound up in the oil, 43 PPM
> in 5 quarts of oil would amount to a square of lead 1 centimeter square,
> by .006" thick.  I opened the oil filter and found metallic bits, not
> unexpected in a rebuilt engine.  Still need to rinse the element in
> solvent, pour it through filter paper and examine what is left.  As a
> test, aluminum will dissolve in lye, but lead will not.
>
>
> The engine has no startup knocks, no knocks when hot when teasing the
> throttle.  Also, I moved the pickup back by 3-1/2" which has to help
> starvation tendencies under acceleration.  It has 40 PSI oil pressure
> when hot at about 2500-3000 RPM, although it does read close to zero at
> idle (all on the stock gage with a new sender.  I still need to check it
> with a real gauge although the sender was replaced).
>
>
> Tin was low, at 5 PPM, which would indicate that main and rod bearings
> are not at fault.  Anyone have any ideas?
>
>
>     Bernie
>
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>



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