Ethan wrote:Thanks guys! the valves are already done, they have a little clatter but for the most part are relatively silent
Ethan, forgive me if I insult your intelligence, but I just want you to make sure you know the difference between a mechanical valve lifter, like your truck has, and a hydraulic lifter, that most modern vehicles have. The mechanical lifter NEEDS to have some gap between the moving parts. If there are no clearance between the parts, all parts of the valve train would expand when they get warm and it would keep your valves open. If you have open valves, you won't have any compression. The "click, click, click" that you hear with a mechanical lifter is the gaps that you have with mechanical lifters. Having mechanical lifters can also be a good thing with engines that run at extremely high RPMs because you don't have a lifter that pumps up and keeps your valve open, like a hydraulic lifter can.
A hydraulic lifter adjusts itself, but technically, it never has a gap. That is why they run quiet. On a brand new engine with hydraulic lifters that has never been run, there are gaps in the valve train and when you start up your engine for the first time, it will sound like an engine with mechanical lifters, at least until the lifters fill up with oil and compensates for the gaps. Ideally, you never have to adjust your hydraulic lifters again. If the clearance between the valve train increases, hopefully your lifters just fill up with oil just a little bit more to compensate for the larger clearances that can happen as your valve train wears. If your valve train clearances decrease, as in the case of when a valve seat wears and the clearances get a little tighter, the lifters bleed down slightly so that there is less oil in your hydraulic lifter.
Once again, I apologize if you already know all this. The little clatter that you hear is a good thing.
Sat Mar 22, 2014 9:08 am 
