seal swelling oil additives ???

[doskow@domain.elided (MEL ODIOUS)]

i have no experience with such additives, but the addition of seal swelling
substances sounds like a really bad idea.  a chemical that would make 
an elastomer expand would alter its structure making it more likely to
break down, greatly shortening its life and causing leaks.  perhaps even
more importantly, the additive wouldn't be able to distinguish between
static and those dynamic seals which are critically sized to be able to
optimally prevent leakage while allowing shafts which pass through from
inside to outside the engine to turn.  so while perhaps temporarily helping
some gaskets to hold tight, a swelling additive might well cause premature
failure of crankshaft, camshaft, distributor etc. seals.
jak

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