[4pipes]

I finally have one that doesn't leak, by paying attention to each source and driving them to zero.....but it's probably temporary and not really worth the cost. My Fe is all aluminum and since it is held together with ferrous materials the differential expansions can be enormous. After many heat cycles I think it may be unrealistic to expect them to not leak. I think one of the most effective insurance policies is to make sure that there is plenty of crankcase venting. At high rpm's the internal pressure is high enough to create leaks.