Seized engine , atf & acetone?

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A friend of mine got a 35-foot Chris-Craft for next to nothing, the boat ran in the last 2 years. We are pretty sure it is seized from sitting . He has put mmo in the cylinders a few times in the last month and it has been sitting but will not spin over. Does anybody have a suggestion on what else to use, we were wondering if ATF and acetone would do damage to the Rings or Pistons or cylinders. His next step is pulling the heads, he says he can get a rebuild kit for very very cheap. He has tried using a breaker bar to spin it . Any suggestions? thanks
 
Try banging on the end of a breaker bar with a rubber mallet. It could be so seized up that you're not going to free it up, especially if it was used in salt water.
 
Stern drive units can also lock up in the stern drive. There are several bearings and gears that spin all the time with the engine. The forward-neutral-reverse clutch is right before the propeller.
 
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I think it's a late 80s early 90s Chevy 350. It was used in saltwater, I'm waiting on a reply from him now.
 
IF this were a vintage Chris-Craft engine from the 30s, I'd go to all the effort to save it. But its a dime-a-dozen Chevy. Even if it breaks free, a rebuild would cost as much as a fresh crate long-block.

That said, if he wants to try it, nothing mentioned will damage the rings. I'd probably skip the homebrew and go with Kroil, as recmmended above. That stuff is a step above even PB Blaster on the penetrating oil food chain.
 
Originally Posted By: 440Magnum
IF this were a vintage Chris-Craft engine from the 30s, I'd go to all the effort to save it. But its a dime-a-dozen Chevy. Even if it breaks free, a rebuild would cost as much as a fresh crate long-block.

That said, if he wants to try it, nothing mentioned will damage the rings. I'd probably skip the homebrew and go with Kroil, as recmmended above. That stuff is a step above even PB Blaster on the penetrating oil food chain.



Agreed, my wife's grandfather has (had, he recently passed) 1929 Chris Craft that he pulled the original Plymouth motor for a blown out 350. He kept the engine for restoration purposes but if you cant get it cranking it is worth saving up and throwing in a new 350. They are common and not terribly expensive. I would be more concerned about the out drives and any salt damage. Ours is used at a fresh water lake (Saranac Lake in NY) so it doesn't have any issues with salt corrosion etc.
 
He is a heavy duty mechanic by trade and I believe his intentions are a driveway budget build probably ringsand bearings, quickly hit with a ball hone and reseal if that is possible
 
Gotta figure out why it seized? If the engine went under and it was salt water and it was not flushed and re-oiled in 48 hours (?), it's pretty much an anchor. If it had a leak into one cylinder, that's a different story...

Should be able to get at the flywheel... Long bar on some ring gear teeth with all the cylinder loaded with diesel. Kroil is great, but for an unknown, I would not put the money in. Diesel will get behind anything savable.

Do you have a dipstick oil change pump? Pump the crankcase and see what comes out? Pop the valve cover and see what you see. If chocolate milk and rusty crud, just pull the engine and get to work...
 
The ATF and acetone is a great seeping solution to help freeze stuck items. It will work. I would not be worried about the seals as gaskets, if the engine is seized, it is going to have to be torn down and rebuilt anyway, more than likely.
 
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