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47 Special Motor stuck


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So the stock 248 in my buick is stuck probably due to the hood being off the car for 10 years outside and nothing more than a rock and a peice of rubber over the carb. I've seen a few posts here that suggested marvel mystery oil or various other fluids and lots of soaking. But due to even the carb being frozen up solid from the elements, wouldn't it just be better for me to pull the motor and trans for a teardown? I'm gonna have it hot tanked anyways to clean out all the oil passeges and coolant. Basically is it worth the effort now to see if it will turn or just avoid doing any damage and go straight into pulling it for a tear down? Probably a good idea to do a once over on the internals anyways right? It drove to where it sat for 10 years and we all know the classic ran when parked.:cool: Lastly I've done stuff with sb chevy motors but never a straight 8 besides get the one in my old road master running. Anything I should watch out for or know before teardown?

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Let me tell you a story. I recently took part in this little dance and its not easy. I purchased a 1950 buick that was supposed to be a running car, well it wasn't. It had water intrusion in 2 cylinders via the open intake valves on 8 and 6. I tried every oil and time and heat but that thing was stuck. I ended up pulling the motor and trans as a unit, pulled the head off and beat the crap out of those 2 pistons and they never moved. I just sold that car and engine this week with those two pistons still stuck in the block. Then there was my 52 buick. This car the head was removed in 93 and placed in the trunk until i got the car last year. This engine was also stuck but the bores looked good. I tried atf, brake fluid, paint thinnner, and would let it soak for a week and then i would put a breaker bar on the crank. After weeks of failure i got serious. I machined a adapter to fit over the crank snout that would utilize the the crank key way. This allowed me to put a 48" inch pipe wrench over the the adapter i made with about 6 feet of pipe over the wrench handle. Then i put kerosene into all 8 cylinders (head off the block) stationed a fire extinguisher close by and lit it on fire for about 30 minutes. Then i let her cool down. Then i fired up the fireball (pun intended) again for another 30 minutes. Once she the block was nice and warm i had a 250 weight (my buddy) on the end of the wrench. Finally it broke loose. We danced around the yard doing the we just broke the motor loose dance. I removed all the pistons from the block to find all the rings were stuck to the pistons. It was bad they had no ring gap and would not even rotate around the piston. So i replaced the rings and rod bearings. So to answer your question i would throw a 50/50 mixture of gas and oil, marvel, sea foam or just plain engine oil directly in every plug hole and let it sit for a week. Then try the starter. If she dont crank it doesnt look good. I would save your self the trouble and yank the head. Then you will be able to see exactly what is going on. It is also possible that the crank and pistons are not stuck but actually the drivetrain.

Good luck

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You will get more turning force using a 2 foot pry bar on the ring gear teeth than a 6 foot bar on the front of the crank.

Using the head bolts or substitutes fashion a heavy steel plate over the piston and then construct a large fine thread screw in the plate over the piston. Place a piece of wood over the piston and some steel plate over that for the screw to bear against. Even this will not break it loose instantly...let it sit with tension and try turning the screw daily. This will only work if there are only one or two stuck pistons. Another way that most of us don't have is to remove the rocker assembly (and hopefully the valves on the offending cylinder will be closed) and apply hydraulic pressure through the spark plug hole...even forcing grease under pressure has a chance of working. Be aware that if it is stuck hard the cylinder walls will be pitted and may not clean up with just boring...may need a sleeve.

Willie

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I had a hard time getting to the teeth on a 50-53 dynaflow trans. The cover only allows access to the front of the flywheel for removal of the flywheel to converter bolts because the belhousing is a complete shroud. The piston method will only work if it is in between the top or bottom of its stroke.

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I never tried the starter but thats because all the wiring for it is missing. If I remember right these are positive ground? Anyways I only tried with a 2 foot breaker bar on the crank with no results. I'm gonna pull the plugs when it gets a little warmer out and see what i've got going on the the cylinders rust wise. If I don't see anything I will move on to the marvel mystery oil and so on routine. Laslty would the jarring force of an impact be of any use at all or the straight force of a breaker or pry bar?

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Fill it up with some marvel and or atf and forget about it for a while. While you have the plugs out shine a flashlight in there and see if you can see any rust. Also a rusty spark will indicate bad things. Throw a pipe over your breaker bar. If still no luck pull the head.. Two reasons why i made an adapter to go over the crank was because i was paranoid about breaking the bolt off in the crank snout and also it allowed me to rotate in both directions. If you have a manual trans you can try pull starting but i wouldn't love the idea. An impact gun will barely turn a free engine so i dont see it doing much.

Edited by flintbuick
i am dumb (see edit history)
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