Been looking around Craigslist for a 4 bolt Chevy 350 block to build into a 383 stroker motor for a future project and I ran across a "grat deal". The guy selling the motor said it ran fine until it overheated. Well further questioning revealed he ran the car hot till the radiator puked. A few hours later the motor would not turn over with the starter. What are the things that could have siezed it? Oil looked free of antifreeze, no obvious outside damage or cracks. All I really need is a decent block to build off of this one can be had for 80 bucks. So now I am wondering is this motor a big turd not worth bringing home?
Drop the pan, look at the crank, for black and blue discoloration on the connecting rods. Chances are, if he got it that hot to seize up, the crank, rods, and possibly the block are damaged. When in doubt / check it out.
There's an outside shot you'll be paying $80 to haul his scrap away. Good deal for him. Known good blocks are not that hard to find, and not that much more $. I'd pass.
Have you tried a breaker bar on the crank bolt? I'd have to see for myself whether or not it was actually seized. Dropping the pan is a good idea if the seller will go along with it. Bob
You are going to be replacing the whole rotating assembly anyway and boring it....so all that matters is it doesn't have a hole in a cylinder....even if it does it can be fixed.
Then there is the chance of spun/warped main bearing, Warped deck, spun cam bearing, cracks in deck and above the cam/lifter area. Pass on the deal. offer him scrap iron value if you must have it and want to take the chance.
summit sella a completely machined 350 clearenced to build a 383 around $600 . you will probably drop almost that much on what could be a junk block
Does it spin by hand? If it does, I'd give it a shot. If not--- goodbye. Apparently you looked at the oil. Was it black and chunky? If so it was really cooked, if not then I'd have some confidence that it was a minor overheat. A simple boilover usually wouldn't cause a seizure. This guy may have driven it to death (people tend to do things like that). A seizure results from some metal actually melting and fusing to other metal. That requires a lot of heat and total loss of lubrication. I'd give the guy half now and the other half after inspection. If it fails, you can at least recoup around $0.08/pound at the scrapper.
I've seen more than a few heat-seized cars and trucks come into one shop I worked in. I recall that all would spin once they were cooled off. If this one remains to be stuck, I'd be inclined to pass on it. Even a decent complete core engine for $200-300 is better than a potential bag of snakes. Bob
ran a vortec block without water in TX and it seized, cooled of and turned over, long story short, cracked heads but saved roller 4 bolt with new rings and bearings.
There are many places including GM that sell new 350 blocks. You will be money ahead buying new that is already machined and ready to assemble.
Where you save your money now, youll spend it again later. I'd do some more searching if I were you. Posted using the Full Custom H.A.M.B. App!
Did anyone mention it may have just blown a head gasket and filled a cylinder with water? Pull the plugs and see if it'll turn (while looking for water out of a plug hole)
I'd pass. There's far too many good SBC's out there to take a chance on this one. FWIW, you could get a 2-bolt main and buy some splayed-bolt main caps. Then it'll be stonger than a stock 4-bolt main block.
^^^ what he said if you have to have a 4 bolt this is your best bet but get ready to spend some money and you must be planing on some big H/P to need it.
severely overheated 4 bolt blocks crack in the main webs---studs in a 2 bolt block are much better than factory 4 bolts, according to many top engine builders...
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