Re: Why do Valves Stick?

Posted by HH56 On 2013/7/6 17:28:29

They do stick -- carbon, varnish, rust you name it can build up on the valve stems. The hot stem can bake it into something hard as a rock and act like glue between the stem and guide. Sitting seems to be the big contributor. I know I bent a few pushrods on a V8 that had sat and the valves rusted to the guides.

I don't think V8's were quite as prone as the long 8's but there are several tech bulletins -- particularly on the early 40's 356 engines where it was a continuing problem. Packard mentioned several causes and tried several "fixes". Ultimately it came down to more use, slightly larger clearances and better crankcase ventilation for those engines.

As to the fix, a couple of people recently have had to tear their engine apart using brute force to free them. If the situation hasn't gotten too bad possibly some snake oil for sticky valves in the gas or down the carb throat might help.