seized slant six

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roadripper

roadripper

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hi there have a 68 valaint 2 door post 19000 original miles been sittin for a long time !!! the six is seized :angry7: any ideas how to break this free without doing too much damage to motor or am i better off to tear down and rebuild:-?
thanks



mike
 
Haven't done this in a while, but you can use diesel fuel, it will act similar to WD-40. Pull the plugs and fill up each cylinder. Let it sit a couple of days......... Drain it out, add a little ATF or MMO to each cylinder for lubrication then get a large breaker bar and try to bump/crank the motor and free it up.... If you can get it t crank then fully drain and clean it out. Add new fluids, spark plugs, wires, cap and rotor etc....... Change the fuel filter. Use some brake parts cleaner spray and flush out the carb. I find that the brake parts spray cleans out varnish and crud better than carb cleaner....... If you can get it to start then grab a timing lite and set that as well. Let it idle a while and warm up.... Once this is done you will also want to run a compression test to see where it's at condition wise...... Judging by the miles it will most likely be fine unless it seized due to broken internals. If it's just from sitting it can be saved. Clean out and flush the radiator, power steering, etc....... Basically all fluids. Drop the gas tank and clean that out as well.
 
It's been a while but I've used the methods above to bring back plenty of cars as well as even some lawn equipment. Fun taking a free dead mover that sat to long or gunked up and bring it roaring back to life........ Then clean up the body and tune it. Sell on CL for a quick profit to spend on more car parts......
 
I kind of agree with what the MoparMan laid out. I'd go straight to the Marvel Mystery Oil and put enough in each cylinder to make sure the entire top of the piston is covered. Let set overnight. Bump with breaker bar. Be prepared to deal with what ever comes out of the spark plug holes. Recommend a big sheet metal drain pan.

You'll probably wind up with scored cylinder walls, so a rebuild and honed bores will be the minimum necessary. You can run it for a while, but the engine may not get proper compression or have effective oil control. Hold off getting a rebuild kit until you find out if the block will need an overbore or not. If on the other hand, you get good compression and the engine doesn't smoke like an old outboard motor, pat yourself on the back and enjoy. Of course, once you know the outcome, change the engine fluids while the engine is fairly warm.
 
50% ATF and 50% acetone.
 
Or try kroil, or pb blaster, some kind of penetrating oil. Fill the cyl to cover the top of pistons to cover the rings all the way round. I'd let it sit for a few days and keep sticking oil in it. Then I would remove the valve cover and squirt some down the stem of each valve, pre oil if you want. Break it loose with a bar then with the plugs out crank it over for a few seconds, spray oil down again and crank it a few more seconds this will blow a lot of crud out. Good luck
 
Before you get too involved it pays to make sure the starter isn't hung up in the ring gear. I have ran in to this a couple of times when trying to loosen up what I thought was a seized engine.
 
Dealt with this on a 65 V-8 that had been left outside with the intake manifold off, and facing up. After pulling the heads and trying everything suggested (ATF, brake fluid, kerosine, WD40, ...) for 2 weeks and periodically working on it, I got frustrated and beat the pistons out with a wood block and sledge-hammer. Messed a few up, which is a shame since the rare HiPo pistons. I should have waited 1 yr and beat on them a couple times a week, since the engine has been sitting since. Anyway std pistons aren't much value today unless one finds a pristine block or sleeves all cylinders.
 
+1 on the marvel mystery oil, i have freed up a vw engine and countless small engines with it.
 
hey there thanks for all the ideas , i ended putting diesel fuel in each of the cylinders let it soak for about a week and tried cranking it with the starter. The fan moved about 2" but wont move anymore :wack: so i put more diesel in the cylinders to let it soak :prayer:hope fully this works. Do they make a tool that will attach to the pulley on the bottom of the 6 ,so i can crank on it without using the starter ??


thanks mike


68 Valiant
 
Yes. It's called a bolt. Clean the threads out in the end of the crank and get a bolt for it. Chrysler tapped threads in the crank, but never used a bolt.
 
After you use the lubricant of choice on top
of the pistons, I usually try turning the engine
over by the flywheel with a flywheel wrench.
I get more leverage there.
I move it back and forth small increments until
it frees up so I don't ruin the rings or score the cylinders.
After it frees up I run it through a couple of cycles by hand
then with the starter.
I usually mix Marvel in with the fresh fuel to help lube and
clean things up.
Hopefully its not stuck too hard and the rings are not
seized in the ring lands.
Good Luck!
 
RustyRatRod said:
Yes. It's called a bolt. Clean the threads out in the end of the crank and get a bolt for it. Chrysler tapped threads in the crank, but never used a bolt.
Click to expand...

Yep....3/4" UNF they are.....which is lucky....coz I gotta fit a bolt n washer for drag racing rules.
 
Had no idea that the end if the crank had threads in it :D, so much crap in the hole , and hard to see with rad in place :protest: Thanks !!! will keep u posted Mike
 
Clean out the center of the crankshaft pulley. A ½" drive 24" breaker bar with the appropriate socket is usually enough to bump the crank around.
 
Since it move a bit one way, then stuck, try reversing it. Keep adding diesel and going back and forth. If you try to force it one way, the rust junk will stay stuck under the rings and may score the cylinder walls. Your goal is to flush the rust out.
 
Tried soaking motor with diesel /oil in cylinder walls no luck motor won't turn even with A big *** swing bar on the end of the crank:banghead: so last night pulled the motor trans out to do a tear down :protest: may go v8 after all Lol

Mike
 
lot of work and money to change from a 6 to an 8, if you do it right. my 69 2 door slant, broke a ring and then the ring broke the top of the piston. i have a newly rebuilt 360 on the garage floor and thought about dropping that in, but dont want to make all the other changes.
 
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