Quote:
Originally Posted by Radiation Joe
My Redline blends (50% 5W-30 street, 50% 40W race) come out at 7k to 8k miles with the same viscosity they went in with. Here are three runs right after changing from TWS.
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Hi Joe -
How did the phosphorous/zinc get so high? I know you surf BITOG so you may have already seen this thread on excess zddp -
http://www.bobistheoilguy.com/forums...2481655&page=1
Here's an excerpt -
In December, 2007, the publication GM Techlink, distributed to GM dealers, contained an article by a GM lubrication guru, Bob Olree, of the GM Powertrain Fuels and Lubricants Group. As well as debunking certain other erroneous ideas about oil, he addresses the ZDDP question in detail. In that article, he flatly calls the concern about ZDDP a “myth,” citing the extensive testing of modern oils for scuff resistance. One paragraph is especially worth repeating here:
A higher level of ZDDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.
So, more is not necessarily better. It’s a good idea to keep this in mind before using high-ZDDP racing oil, diesel oil, or any other additives in a street engine.