I recently replaced the valve springs on my mustang with Explorer heads with the trick flow valve spring upgrade kit along with stock length Ford pushrods and stock replacement hydraulic lifters the roller rockers are stock so is the manifold now after startup it is quiet and very little noise but after warm up it starts ticking tapping and gets much louder as the RPM increases I'm running 10-30 oil can anybody give me any suggestions on what to look at next thank you.
Have you considered that exhaust leaks sound a lot like a loose valve? A length of hose that is long enough and flexible enough to snoop around the exhaust flanges while you listen to the other end is a helpful tool for finding exhaust leaks.
thanks jrichker took your advice and put the car on stands today and removed my cheap catted xpipe after it was removed it was clear I had leaks and a few not so tight bolts oops after installing the stock H-pipe checked for leaks non wear found and the tapping seems gone but I can still hear a tapping in what sounds like the # 4 cylinder but it does a fairly hard well serviced attleast since ive had it but hard milles on the bottom and rear end have about 180000 miles them tranny and drive shaft have low miles going to check to see if it a lifter its brand new soked in oil or a rounding cam lobe over the weekend any suggestions are welcome thanks.
I would pull the valve cover and check the rockers again for proper preload. You can get shims up to .060 to achieve proper preload, if you cannot get them within spec with the shims then measure for custom length pushrods to correct. Normally you want 1/2-3/4 of a turn past 0 lash to achieve the correct preload on the lifter.
When you are adjusting the lifters are you certain they are on the base of the lobe and the lifters have had the opportunity to pump up? I normally wait about 30 seconds or so after rotating the engine to check.
Finally, hate to say it but this wouldnt be the first time a new Ford lifter was bad out of the box.