I have been working on an 8n that had been setting for 6 or7 years. Replaced Battery, coil, plugs, points, condenser, rotary button, dist cap, plug wires. Intake Tapets were sticking on cyl 1& 2. Got them freed up through side panel. Hydraulics would not lift. Valve was sticking in pump, got it freed up, changed transmission fluid (seems to be working fine). Changed oil and filter.
While running it lost oil pressure and head a screetch. Engine was not locked up. Put oil in oil canister got oil pressure back. Itís around 40 psi. When hot it drops to around 20 or a little below. The problem: sounds like a valve chattering. Compression test show about 70 on cyl, 90 on 2 & 3 and around 70 on 4. Compression test seems to indicate good rings. It does seem to indicate valve sticking. But they look like they are moving free. It does have adj valves. Does it sound like valve adj or something else? Thanks