Just started up my dad's 65 f100 after sitting for around 10 years. I let it idle for around an hour and it's still smoking out of the exhaust pretty bad. What can I do, or are the rings toast? It's a 390.
Italian tune up? Is it blue, black, or white smoke? I'd make sure its not running on all cylinders first, then check the plugs, then heat cycle it a few times (warm up, cool down, rinse and repeat), then do a compression check and go from there. My f100 with a 390 sat for about a year and I just got it running again this week, it smoked a bit (blue, oil smoke) the first few times I started it but now its not, just took a bit to get its joints loosened up I think.
Try new oil & filter, exchanging 1 quart of oil for Marvel Mystery oil. Start engine and bring up to operating temperature. Dribble a pint of MM oil through carb just enough to keep running, then before it is all gone, dump the MM oil fast enough to kill engine. Let sit for an hour, then start up and drive for 30 minutes at a brisk pace. It should blow out the carbon and loosen the rings. Once it cleans up, replace oil and filter. I've had good luck on several vehicles using this process. Good luck!
Two things you can do is pull the rocker covers and check the valve seals, if the seals seem intact then slowly pour some Bonami through the carb while the engine is running, it will break the glaze and help the rings reseat.
Intake gaskets on fe motors are nortorious for failing and either sucking in oil or water into the combustion chamber
Bon Ami and water mix: Old trick used by the 'masters'. Used it personally on 4 or 5 old flathead V8s, (couple of them 'stuck', had to pour brake fluid in spark plug bores for 3-4 days to free them) One in particular came from a '46 Merc, sat in a field for 8 years. Stuck solid, soaked it with brake fluid, forced 'turnover' with 4 guys, rocked back and forth in high gear...finally broke loose, rocked it more and more...until we could push it in high gear, engine turning over. Changed oil, replaced plugs... Started engine, smoked to beat the band. Ran it for 15 minutes, mixed some Bon Ami and water, poured it down carb @ about 2,000 RPM. Smoke persisted for 2 minutes (tops) then just vanished! Ran the engine for awhile, started it when cooled off, no more smoke. Engine was installed in my channeled '30 Coupe, got a Navarro 2 jugger with rebuilt 97s, ran smooth and strong...did steady back and forth between Santa Clara and L.A. 7+ times, never a problem. Sold engine to a guy with a '36 Coupe, he ran it for years. Of the few flatheads I did this to, only one failed the test. Head and pan removal revealed 3 pistons cracked, broken rings and lands. (damage had occurred years before the Bon Ami test)
Pull the valve covers spray the parting line between the head and intake with choke cleaner with engine at idle. Any change in idle means bad gasket. Retorque manifold and try again. Also check oil drain back holes.