Fragged the old 440. LY rods, 2355
pistons and 6500-6800 rpm shifts. Boom. I
bought a low deck 500 stroker shortblock.
Max wedge heads, 292 cam, 2 in. TTi headers.
800 vac. sec. carb, single line external
oiling, Melling HV pump. Almost 80 psi at
cold idle, 50 hot. Way too much crankcase
pressure blows the dipstick out, oil pours
out the rear seal. Any thoughts ? I don’t
want to pull this engine, it’s a major pain.
In almost every case, excessive blowby
is products of combustion getting past the
rings. There will always be a small amount
of blowby, and I have seen guys who have
no crankcase ventilation blow oil out as
you described, but your pix shows some
ventilation so that’s not the problem.
The most common causes are rings
never seated, broken rings, or piston/ring
failure from detonation (see pix, above
right).
Since it sounds like bad news, there’s
not much to lose by trying the “nuclear”
ring-seating option: Hold rpm at about
2500 – 3000, pour a can of Comet or
Bab-O (abrasive dry cleanser) slowly
through the carb. I have seen this work,
but I sure wouldn’t do it except as a last
resort.