Senior Tech Team
Join Date: Apr 2012
Location: Yerington, Nevada
Re: Blue Smoke
So, I never suggested a "blown piston", I wanted the info to see if the crank case pressure was too high, pushing oils past worn components that would have worked correctly, IF the pressure was regulated correctly, BY A PROPERLY FUNCTIONING PCV SYSTEM, with lower crank case, valley and valve cover area pressures. For the record, with excessive crank case pressures, air/oil vapor can be pushed past worn rings and pumped into the combustion chambers, to be burned as the engine runs, and if there isn't a great volume of mixture being pumped into the chan=mbers, the plugs could handle the burn off of the small volume of mix.
As I said, I NEVER suggested a blown piston.
And, a compression test with the throttle closed to its idle position, is not accurate, gives low numbers, as seen on this engine.
And, a 1965 engine, with some sort of factory turbo having a blown seal, come on, nothing was said like that at all.
Another area that might, LONG SHOT, be an issue, if, and this is a giant IF an automatic transmission was allowing air/oil to migrate up a blown vacuum modulator hose into the base of the carb, or inlet manifold, but you'd expect to see that in all 8 cylinders. OP says the plugs are clean. Blue smoke isn't indicative of calves leaking, whiter smoke is, could be exhaust valves only, leaks into exhaust ports, doesn't alter plug cleanliness, other areas.