Charles Navarro from LN Engineering gave his tech session at our car club
yesterday.
One of the things he said about the modern oils is that, in addition to
lower levels of Zinc and Phosphorous, they are using calcium sulfate
detergents. The wear rate with these detergents is much higher, but they
last longer contributing to the longer drain intervals many car companies
are now calling for.
Without getting into too much of the technical stuff, he said the amount of
Zn and P needed is dependant on valve spring pressures and that we should
ideally be using a minimum of 1200 ppm up to around 1450 to 1500 ppm for our
stock cars. Using more than that will do no good and, at very high levels,
will start fouling plugs. The moly additives are good, especially for race
motors, and the Boron additives work only in conjunction with high levels of
Zn and P. He said we should definitely be using the same oil with high
levels of Zn and P in our trannies as we do in our motors.
Of the DIY additives, he likes GM's EOS the best and said that the recently
re-introduced product has the same levels of Zn and P as the old stuff --
they just changed the color and made it stink. The STP additives rank as
the blue bottle being pretty lame, the red bottle has a bit more and the new
white bottle (oil stabilizer) has the most. The STP white bottle has about
as much as halfway between the STP blue bottle and the GM EOS.
As to ZDDPlus, he said he doesn't trust it. He hasn't tested it, but, when
it first came out, they called him looking for an endorsement and asking him
to sell it. When he started asking them technical questions, they couldn't
answer him. He figures that this is just a few guys that bought up some
pure ZDDP, diluted the hell out of it and are trying to cash in. He is not
saying it is necessarily a bad product -- just that these guys don't really
know what they are doing. They are just marketing people without an
engineering department.
To be continued....
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