Diagnostic question
I guess I need to go back and do a compression test.
jos, don't bother; repeat the LD with a different gauge. If you get the same results, the engine has been hurt.
One second at 6000rpm is 100 revolutions. If the springs couldn't take it, the lifters pumped up and the cam drove the valves into the pistons, the usual result is all bent intakes, and some bent pushrods; because the valves are opening as the piston is coming up to TDC, at the top of the exhaust stroke; BAM!
If you exceed the springs ability to keep it together, under load and the valves float, the engine usually stops revving. It just goes flat.
But if you overspeed it in neutral, like in a missed shift, flywheel inertia will continue the revs way past the onset of float. It will take a while for the rpms to come back down below valve float, and even longer for the lifters to bleed down. Sometimes taking several to many minutes with the engine at high idle, to keep it running.
If it stalls, you might have to leave it overnight, and at least two cylinders will likely still be dead in the morning. If the valves survived, you will be able to get it running on the six, but just wait; keep it running at say 1500 and soon the other two will come on line.
But if the engine stalled, and won't restart, you can bet the valves are bent. It stalled because of the high rate of leakdown/ lack of compression.
An engine will run thousands of miles at 8 to 10% LD, but it sure won't make power. It will be hard to start, may suffer from detonation, and is guaranteed to make lousy fuel mileage; and if it's the ringseal gone bad,will dirty up the oil pretty quick.
If I ever noticed my engine trending towards 8%LD, I would already be taking it apart. Last time I checked, it was at ~4%, with ~80,000 miles on it.
