Re: Stewart's 1955 Packard 400

Posted by HH56 On 2013/12/30 17:28:27

Just asking because I don't know. I went to the expense of hardened valve seats also and was wondering if it was money wasted after reading some comments.

IIRC, The thinking of those against is with hardened seats the valves will be what is taking the wear disproportionately. In a normal strength valve that is ground to a relatively small contact area it will degrade faster because the seat will be hard and valve will be softer and hotter so material will be easier to pull off or rearrange. With both components of a same relative strength then it would be a more even wear.