Classic/Antique Car Repair: Noisy hydraulic lifters, hydraulic valve lifters, hydraulic lifters

Question
The engine (263) of my 1950 Buick has been completly reuilt and runs superb except for very noisy hydraulic valve lifters. When the engine warms up, the lifters are somewhat less noisy but nothing like my whisper quiet 1949 Packard Super Eight that has NOT been rebuilt! I just wonder if the Buick straight eight engine is by nature noisy, and if not, what my problem might be. I use premium 10-40 oil and change oil and filter q 6 months; maximum mileage between changes 1500 miles at most.  Thanks for your help.
Sincerely,
Charlie Cain

Answer
Well, I am a lifelong Packard fan (and driver), so I could just say that the Buick is not going to be a smooth or quiet as a Packard, especially if you have hydraulic lifters in your Super 8 (there will be an "H" after the engine number), but I think there is a problem with your Buick if you are hearing valve noise.  These engines are overhead valve type, which means that there is an oil supply line that lubricates the upper parts of the engine. Buicks of this era and earlier are famous for problems with this oil supply, and I suspect you are suffering from the usual problem.  You could prove it by taking the valve cover off, and then drowning the moving parts of the valve gear while the engine is idling - if the noise goes away as soon as you supply oil to the moving parts, you know the pressure feed from down below is blocked or disconnected, or otherwise not working.

If your oil pressure is adequate (30 PSI or so with warm oil), the valves should be quiet enough that they don't bother you.

I would not drive the car until you find the cause - if the valve gear up top is running with inadequate oil, it is doing damage to your fresh new engine!

Dick