How to unseize an engine?

[FastOrange]

Hey guys, i bought a very complete low mile 1976 454 the other day for $100, this thing is complete right down to the vacumm lines, but the engine is seized.

dude said it ran awesome when he pulled it 20 years ago.

i have had ATF and penetrating lube (Moovit) in it for a couple days now, still is tight as hell.

i do realize this is going to need at the very least a re-ring afterwards, if it was a 350 i would just scrap it, but being such a complete 454 i have good hopes about it.

any ideas? how long should i let it sit? should i put the plugs back in after i put lube in the cylinders?

 

[KReePiN]

Buy a gallon jug of wd-40......,pour it into each spark plug hole/cylinder.....,,let it sit for a week.....leave the spark plugs out cause you need to try to turn the motor over by hand with a breaker bar after its been soaking for a good week or longer....90% of the time your going to need to rebuild the motor but ive seen a couple friends get lucky,and actually have a good running motor after unseizing it


Sent from my iphone while im sitting on the toilet

 

[great white]

20 years of Canadian winters with at least some open valves?

Put it on the stand and whip the heads off.

Then flip it over, tear it down to just block rod and pistons and shatter the pistons if you have to to get them out of the bores.

Forcing then down the bores will likely score the bores at this point. I'd just collapse them. That's not an easy job either and can ruin the bores also.

The rings and cylinders are likely rust welded into one piece by now.

Likely looking at oversize pistons at this point anyways.

You can keep soaking it, but my money is on a teardown to get it done.

It's usually not this hard, but sitting 20 years is going to make it a mess....

 

[badazzbulldog]

marvel mystery oil load the cylinders let it sit for a few days,breaker bar with a pipe on it for leverage, good luck!

 

[FastOrange]

20 years?

Tear it down and shatter the pistons if you have to to get them out of the bores.

The rings and cylinders are likely rust welded into one piece by now.....

I dont think its that bad, had the plugs in and the carb on it the whole time, in a shed with a tarp over it.

ive been reading online, 100's of people have gotten engines to free up that have sat for way longer then this.

in the long run you might be right, i just dont have the space to tear this down, god i hate living at home again!

 

[FastOrange]

marvel mystery oil load the cylinders let it sit for a few days,breaker bar with a pipe on it for leverage, good luck!

cant get MMO here, sadly.

im going to get a couple cans of Fluid Film, load the cylinders right up.

 

[poncho62]

WD40 is crap......You have the right idea with the ATF. Mix it 50/50 with some acetone. Put some in the cylinders and let sit. Try and turn it each day. If it gets slightly loose, move it a bit.....let sit again, move a bit more. Taking the heads of and looking at the cylinders is a good idea too. Will show you where it is likely seized if nothing else.

Also, loosen the valve train off......makes it a bit easier

 

[FastOrange]

WD40 is crap......You have the right idea with the ATF. Mix it 50/50 with some acetone. Put some in the cylinders and let sit. Try and turn it each day. If it gets slightly loose, move it a bit.....let sit again, move a bit more. Taking the heads of and looking at the cylinders is a good idea too. Will show you where it is likely seized if nothing else.

Also, loosen the valve train off......makes it a bit easier

Ill loosen the valvetrain for sure. i forgot about ATF/Acetone mix, ill try that first.

my buddy said he has done it with diesel fuel, but i know it smells pretty strong.

 

[FastOrange]

this is the engine btw, After i cleaned some stuff off of it. (Distrbutor, carb, wires, lines, etc)

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was attached to a TH400, we picked up the whole package for $200, My dad and I split it 50/50, i get BBC, he gets TH400.

 

[great white]

Spark plugs installed is not the problem. Open valves and humidity on bare iron bores is the problem.

Lots of humidity in BC.

Load 'er up with oils and let 'er sit. If it comes loose: great.

If it doesn't, well.....