What oil are you running?

 

10w30 VR1, that’s been the same oil I’ve been using since the first build

 

High zinc, created for flat-tappet cams...... I don't see how that would really be a problem..... but, might be tempted to run a standard 10w30 dino oil for one change, and see if it makes any difference.

 

I did do that for both break in periods for the cam (I know they really don’t need one), and for a ring break in (300 miles or so), just using basic conventional. I use VR1 for the interval oil changes. Didn’t make a difference

 

You have a head-scratcher there. Valve stem heights are all the same and correct, I assume. Keep us posted, I love a mystery.

 

This thing is going to make me go bald by the time I turn 25 lol.

The heads are from Odessa, which HeyYou actually recommended to me in another thread, and I trust his judgement. My biggest confusion is just that after all this preload change, lifter change, and rocket arm change, that the sound itself did not change.

It seems like it could be a cracked primary, but then the dead cylinder test I’d imagine would change the sound. It could be piston slap but again I feel like the sound would get worse with higher rpm, and go away with a dead cylinder. And it also sort of reverses the expectation of an exhaust leak. Quieter cold, louder hot, and normally it’s the opposite. I don’t get any sparkles in my oil either. I barely had any even during the ring break in.

 

Well... as my ex-father-in-law used to say, his bald head was a solar panel for a looooove machine.

 

I got a stethoscope today, and poked around the engine as it currently sits. On the intake runners, valve cover itself, and the baffle, I can hear a faint ticking sound everywhere around the engine. But on the headers, both on cylinders 3 and 4 (second from the front on both banks), I can hear a very different clicking sound vs the other 6 cylinders. Do I have my smoking gun? Or am I just hearing weird sound dynamics

 

I am late to the game, but I don't mind jumping in... I can be the water boy. Perhaps grab your stethoscope and probe the underside of the engine around the cylinder. 3 & 4 (pan area), sides of the block... I feel you are in the general area. You running flat tappet or rollers?
Completely unrelated, but I recall in the old days, when a Chevy mechanical pump would start going bad, it would make a clicking noise that transferred around the motor.

 

It’s worth a try, I’ll see if I can do it at work later on. I’m running rollers.