nailhead has been sitting for years, oil in engine and coolant level was topped off when parked..Seems as though the engine has seized from rings to cylinder walls...Tried bumping it with starter, juice hits solenoid and seems to engage flywheel with no turning of the crank...Cannot turn crank bolt to the right with breaker bar and socket and turn crank. I do not want to sheer off bolt head so I didn't continue with the breaker...I'm wondering what crankshaft socket for the nailhead would work....I cant seem to find any info on BUICK BIG BLOCK CRANK SOCKETS....anyone know which make or brand and from where that will do the job? I have filled each cylinder with mystery oil to see if it will loosen up the pistons from the walls...Trying to prevent a complete rebuild....This engine has only 67,000 miles on it...Any info would be appreciated..Thanks!
You need to pull the heads. (at least). It's like pain in the body, sometimes you need to pay attention and not push beyond the pain, else, suffer unrecoverable damage. That's my opinion, retired aircraft mechanic, auto and motorcycle mechanic with more than 40 years experience. But in the end, it's your stuff and experience. "...it's been sitting for years...) <---- we call that , "a clue".
I'm glad you stopped before you sheered-of the damper pulley bolt. I had a 401 that was stuck pistons and crank bearings. I tried to break it loose using chain wrench wrapped around the damper pulley. Bad Idea. I split the hub of the pulley where it goes onto the crank which shattered the timing cover. That engine was so stuck I could have broke the end off of the crank and it wouldn't have budged. The best way to do it is to take the gravel shield off of the trans and rock it back and forth with the starter teeth on the flywheel. If that doesn't work you'll need to pull the heads and figure out which cylinder is stuck and hit that piston with a block of wood and a big hammer. I broke a straight 8 loose that way and it was fine with no further rebuild.
