I have a '58-'62 235 out of a car in my '53 3600. I put a new cam and lifters in it a couple months ago. Since its a car engine I went with hydraulic lifters.
When I first start the truck I get an annoying clacking noise that slowly quiets down after a few miles of driving. It never gets silent, though. There is always a noticeable but not overly loud rhythmic ticking noise.
Heres a video of the noise (when first started):
I took a stethoscope with a probe on it and listened to the valves/valve springs. I found one valve that didn't sound the same as the others. It sounds like the valve is hitting the seat harder than the rest.
I adjusted all the valves again with the engine nice and hot and the sound didn't go away. On a whim I adjusted just that valve while the engine was running and when I tightened the adjuster a quarter turn the noise would stop for a few seconds. After a few seconds the noise would slowly get louder until it was just as loud as before.
Is it possible that the lifter can't hold its oil well enough and it leaking down when it puts pressure on the valve? I have plenty of oil pressure (30+ PSI) and I am pretty sure the oil passages are clear.
