[mrennie]

Have 100 miles on new engine, built around 2014 and first drive last weekend. Stump Puller roller cam with first gen Comp lifters and KRE heads. Running 15W40 oil (why 15W40? I have loose main and rod clearances plus a lifetime supply of free oil).

Multiple lifters had TERRIBLE ticking noise when engine first fired up in 2014 until they pumped up. At the time I built the engine, I was not aware of the issues with sticky plungers and recommendation to clean in acetone before install, and installed them after a quick wash in solvent. After the first startup, they were quiet will all subsequent testing.

Fast forward to last year when I got the engine in the car and fired it up for first time in 9 years. Had bad ticking that I traced to #8 exhaust. Readjusted to 3/4 turn from zero lash, plus added a can of Seafoam and it seemed to get quiet.

When going for first drive last Friday, was originally quiet but after 20 miles I could hear a tick again and traced to back of PS bank, thinking it was #8 exhaust again. Took the car out again Saturday and tick still there but not getting worse. Regardless, I don't like it.

Took PS valve cover off last night and decided to readjust valves using the method Cliff uses, bottom out plunger of each lifter, using a feeler gauge between the valve and rocker (I chose 0.020"), and locked them down when lash was gone then removed feeler gauge.

I marked the rocker nuts on most valves and checked how many turns I had originally tightened them down, and most were around 7/8 turn from zero lash, however #8 exhaust was 3/4 turn from zero. I then started readjusting and ensuring that once the lifter stopped bleeding down and the pushrod just stopped turning, I locked the nut (with feeler gauge in place).

Some interesting findings:

-#8 intake and exhaust pair were very easy to get to bleed down. Each 1/4 turn of the wrench past zero lash took about 30 seconds for pushrod to start being able to spin again.

-most others took over a minute or two to bleed down after 1/4 turn. One in particular took me close to 25 minutes to get completely bled down. Clearly they are very inconsistent

-After adjusting them 0.020" from bottomed out, the new locknut position is clearly much lower than 3/4 to 1 turn from zero lash. My marks were hard to see at this point, but it appears many were 1 1/2 to 1 5/8 turn compared to the previous adjustment.

So I button everything back up and start the car, and initially was disappointed because it still ticked, and thought it was a bit worse than before. Let the motor warm up and after about 2 minutes ticking seems to go away but now I hear the "sewing machine" noise that others have mentioned. Didn't hear this before at all...seems like I have traded the tick for the new sound.Ran the air conditioning and engine got nice and hot, still no tick. Well that is a bit of an improvement I guess.

My #1 goal is to get miles on this engine and do some tuning and enjoy the car. I am not about to spend another 1K on lifters and tear into the motor changing parts unless it is being hurt. The new sound bothers me, but slightly less than the tick. I know (now) that these lifters are a known issue but did not when I assembled the engine and not much I want to do at the moment.

So...aside from the sound, should I be concerned about this? How many have driven with the older Comp (Singer Sewing) lifters without issue?