Thread: chevelle 383 bent valves

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ok i havent opened the motor yet but i think the valves were hitting the pistons. it sounds like a major exhaust leak trough the header but the headers are sealed right and like if the rockers are lose but i checked them and there fine. i have no engine power when i accelerate and it sounds horrible. am i right did the valves hit the piston if they did what should i do

it sounds like it is spark knock either from the timing not being right or having bad gas (not enough octane) that would explain your lack of power try retarding the timing turn the dist. counter-clock wise? someone correct me if im wrong i never really give it much thought i just do it.

A compression tester or a good ol thumb over the spark plug hole will tell real quick if the valves are bent ,you will get no presuure or very litlle pressure.The readings may be wildly different from one cylinder to the next also.

I recently had a similar experience, and my valves were clipping the top edge of the valve relief pocket on the piston. I too thought that my rockers were not adjusted properly, then thought it was a header leak, then thought it was a bad lifter and proceeded to dissassemble the motor. I only pulled the head on a whim and discovered what the REAL noise was. I hope you do not have the same problem but...

BEFORE YOU RUN IT TOO MUCH MORE...Do what ShawnLee suggested (probably easiest) or pull a valve cover, fire it up at a low idle, and use a short wood dowel (14" piece of broom stick) on each rocker stud and it will be VERY EASY to hear where and which ones are making the most noise.

You could also throw a vacuum gauge on there while its running...your vacuum will be all over the place if you bent your valves (like I did, I also had worn valve guides though).

be sure to check the timing also it could be too advanced and put some octane booster in it, to the untrained ear spark knock can sound like a motor coming apart.....does it do it at idle bc if it does then its deff. not timing