rayjr01

Walter, I believe exactly what you just stated. Then he realized that he messed something up and then left it for me to buy and have the headache .

There are marks on all 6 pistons, the one that had 0 compression has the biggest mark. I got very vague information from the guy I bought it from 3 months ago, as it was abandon on his farm 14 years ago and he thinks the guy may have done some work to the motor but he isn't sure. I personally think he may have, that's why he abandoned it knowing he wrecked something internally. But what puzzles me if the timing chain jumped, why would it still run?

ok, thanks for your post. How would I know if it was assembled wrong because I have the motor apart now? It was running before I took the motor apart, but it was running only on 3 cylinders.

I have a 1972 240z I got the car not knowing what the past of it was. After getting it running, it ran really rough. Upon a compression check, 60 psi in 2 cylinders and 0 in one, and 140 psi in the remaining 3. To find out what was wrong with it, I removed the head and inspected the valves. I found 3 bent exhaust valves. Can the distributor be turned far enough one way or another to cause the valves to hit the tops of the pistons? And how did this occur?