Hi guys. I will make a long story short when I was driving my 69 ss with a 402. I heard a pop and the car died out I opened the hood and saw that the positive battery cable was melted. Then I fixed it then the car still did not run right. I heard a vavle noise and did a compression test and #8 #2 had no compression. I took the head off and the valve was broke. One of my frined said that the hole engine was shot because the valve went back into the head and messed up the heads and the block. How could this happend? I was not racing the car. The car did have a 573 lift canm in it and the springs were not changed. Please someone help me how this could happen from just driving the car. Thanks everyone.

 

Sounds like a spring broke and your valve hit the piston. I'd guess that the piston would be messed up enough to need replacement. As for the heads, the can probably be repaired, I don't see where you block may be messed up, unless the piston seized in the cylinder. The battery cable being melted doesn't make any sense to me though, it might be unrelated.

I'm sure some more knowledgeable members will give you a better answer, but I hope that helps a little.

Jeremy

 

Thank you very much. I still am not sure on how it happend? I mean what would cause a sring to break? Thank you for your help!

 

Well, you said your cam has .573" of lift, what are your springs rated to? Did you install the valvetrain and assemble the heads yourself? Are you using rocker arms with a higher ratio than stock (i.e. 1.6, 1.7, 33.4...)?

 

The cam was changed before I had the car. The springs I am sure that they were not changed in the car. As for the rockers I am not sure if they are 1.6 or what I do not know. Sorry for the lack info but all I knew about the car was just it has a bigger cam. If the stock springs were on the car would that cause them to break? Also what kind of things would you think that would cause a valve to break? Because I was thinking that maybe the valves were not adjusted right? But I do not know. Thank you again for your help.

 

Well, a piston hitting the valve is a sure way to break one. If the valves were not adjusted right it would cause damage to the rest of the valvetrain, not necessarily the valves themselves. As for the springs, I wouldn't guess they are good for much more than .550 lift, but I don't know much of anything about stock SBC springs so don't quote me.

My personal opinion, springs were not intended for that much lift and that is your culprit. Don't scrap the whole motor yet though, take it to someone who can tell you what is or isn't damaged. Or tear it down and inspect each piece of the valvetrain for wear yourself. You should be able to tell if the cylinder heads are damaged as well as the block. And buy some new springs

Jeremy

 

Thanks once again. I was tring to find out what happend and then I can go from there thank you very much! I think that was the problem was that the valves were not adjusted right.