[Vwdiesel] Vwdiesel Digest, Vol 42, Issue 27 (fwd)
James Hansen
jhsg at sasktel.net
Sat Apr 28 00:59:12 EDT 2007
Val Christian wrote:
> Higher vis oil, combined with leaky rings, can aggrivate carbon
> buildup in the ring area. This have the effect of increasing the
> leakage, by making the ring "sticky" in the groove. A lighter oil
> may reduce the effect. This is counter general wisdom, which has
> always been, higher viscosity oils in older engines.
And it's only recently that at my level of stock car racing has begun
accepting lighter grade oils. Conventional wisdom was to use high
viscosity 20-50 to "seal better". Now it seems to finally be accepted
that low viscosity synthetics are the way to get better cylinder
sealing, less windage, better bearing lubrication at low clearances (and
yeah, that's what I meant, thanks Val.) Better cooling, maybe because
of thinner oil has less windage, it cools better when not wound around
the crank like toffee.
-james
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