Difference in Valve Gap

[doppx006]

A few days ago i recently set the intake and exhaus valve gap on my truck to the tighter side. My truck has only 38000 miles but I figured it couldnt hurt. The engine seems to actually be a little faster but it doesent sound right and I know I got the valves as perfect as I could and I have some experience setting valves on diesels. One thing I have always wondered was if you set thie intake valves tight or loose in the tolerance range what difference does it make to the enigne, and also what happens if you set the exhaust valves tight or loose inside of the tolerance range what does it do performance, sound, or efficiency wise? Thanks alotfor any help

 

[betterthanstock]

I think gapping to the mid range is best, because as valves wear, you never know whether the seat and valve will recess more (reducing gap even more, and causing possible valve/seat burnout if it leaks) or whether the linkage/cam/rockers will wear faster, which will increase gap, resulting in noise and faster wear, with a mild loss of performance.

Also, when hot, the valve stem expands more from heat than the pushrod(though the pushrod is longer) which reduces the gap even more, and that's why all engines have more clearance on the exhaust valve, since that valve runs hotter.