How do you free a motor that seized from being stored for 2years

[Lance Johnson]

I bought a new crate motor a 1967 Cadillac 429 that been sitting in storage for 2 years and now the motor is seized what is the best way to free the motor

[Lance Johnson]

I bought a new crate motor a Cadillac 429 that's been in storage for 2 years, the motors seized because of the long storage. I was wondering how I could free it?

[Bruce Nunnally]

My late Father would put a small amount of marvel mystery oil in each cylinder and let it soak in, then turn it by hand with the plugs open.  

[Lance Johnson]

Is it really that simple?

[Bruce Nunnally]

No there is luck involved.  But in general for an iron block OHV engine, what has likely happened is a layer of rust has formed between the cylinders and the pistons.  So some form of lubricant that will help break the rust up should let you free up the engine.   There is a lot of varying advice on this topic on the internet -- everything from using a breaker bar on the crank to actually starting a fire in the cylinder to heat it up, or using dry ice on the bottom of the piston to cool it down.  I am a bit more cautious and so I would try letting it soak a bit then see if you can gingerly free it up.  You will also want to get the oil out of the cylinder before you try to start it up later to prevent hydrolock of course.

[Lance Johnson]

Thanks you for the help 

[OldCadTech]

Lance,

More than likely the cylinder walls and the rings are a little rusty. Is it on an engine stand? Does it move slightly or is it locked solid?

Pull the spark-plugs if there were any installed, or the plastic caps and with an oil squirt can, squirt about a spoon full of engine oil in each cylinder and let it sit for about an hour.

Try turning/rocking the crankshaft, if it won't move let it sit overnight and try again. If still no movement rotate the engine assembly so that one bank of cylinders is vertical, let it sit for an hour or so and then turn the engine so the other bank is vertical. Rinse & Repeat as needed. Once it starts moving, simply keep working it back and forth until you start getting complete revolutions, then you can go in the direction of normal rotation, CW if IRC

[OldCadTech]

Lance,

I responded to the engine swap that you posted and I have a couple more questions...

I made the assumption it was a long block. Yea I know about assumptions ?

Does the crate motor have an oil pan installed? If not, this means a few more steps and it would be a LOT easier if you have the engine on a stand so you can rotate the entire engine assy.

Is it a LONG block or a SHORT block? Basically, long blocks came with heads, short blocks did not...

I would approach the seized long block differently than the seized short block. So it makes a big difference...

[OldCadTech]

Looks like there was more than one thread for this.

@Bruce Nunnally or @BodybyFisher can you link this with the other one?

[Bruce Nunnally]

These have been merged 

[OldCadTech]

Thanks Bruce   

[Lance Johnson]

OldcadTech  It's frozen solid,  I put some Marvel mystery oil in it this morning and l have it hanging  on a engine hoist, but It's not level. I'm going to wait a couple of days and see what happens.  Also it is a complete engine that I bought from a gentleman, he has it sitting in  Storage for a couple of years

[BodybyFisher]

If it is hanging you may not be able to get enough force on the crank to break it loose.  Can you put it on a stand?

[Lance Johnson]

That was my concern about the torque, I didn't wanna put too much pressure on it and break Something. We can get it lowered and stabilized so we can Put some torque to it. But my main concern was to get lubricated first.

[BodybyFisher]

I hear you, you will get it, I think @OldCadTech gave you some good advice.  

Let us know how it goes.  

[Lance Johnson]

Sure will, and thanks alot

[OldCadTech]

Lance,

If the engine was stored without spark plugs in a high humidity area it could have serious rusting and pitting of the cylinder walls. That said, You may WANT to dis-assemble the engine.

You'll need to get the engine in a more stable position, either on an engine stand or on the floor/ground where you can get some torque on the crank. You can rent an engine stand at some auto parts stores, or invest  in one. They are pretty much a necessity in engine swaps, TWO of them....

Of course there IS a fine line between the right amount of torque and too much, so, as @Bruce Nunnally stated there is an amount of luck involved. A ROCKING MOTION is what you want to create. Unfortunately the timing chain will be working against you because of the slack in the chain and gears.

One option and the safest to prevent engine component damage is to disassemble the engine, clean, lube and re-assemble. Depending on your mechanical experience and tool level that may not be an option for you. As a side note, it doesn't require a lot of specialty tools to dis-assemble an engine and re-assemble it, again, most auto parts stores will rent them.

Another option is to take the engine to a reputable, and trusted repair shop and have the engine work done professionally. This option may not sound like the best economical choice but it could be in the long run. 

[Lance Johnson]

The motor was stored with the spark plug in it. He said it was a remanufactured engine so I don't think its a big problem just have to get it loose, If Necessary I do have some automotive experience so tearing it down should not be a problem. Also I checked online you can buy a engine stand from between $25 to $50 bucks 2 ton, so I might go in that direction. 

[cdgrinci]

If you could beg, borrow or steal a borescope it might tell the story in a flash.

[BodybyFisher]

I am not a big Harbor Freight fan but I bought their engine stand and it was well made.  I used it with the Northstar I must note, and the 429 is heavier, but I thought I would pass that along

[BodybyFisher]

2 minutes ago, cdgrinci said:

If you could beg, borrow or steal a borescope it might tell the story in a flash.

Good Idea

[rockfangd]

8 hours ago, BodybyFisher said:

I am not a big Harbor Freight fan but I bought their engine stand and it was well made.  I used it with the Northstar I must note, and the 429 is heavier, but I thought I would pass that along

How did you mount it?

IIRC I had issues with 1 bolt so I never put mine on stand. I wanted to, It may have been due to the crossover. It has been  a few years.

I did my 350 on it without much issue. Could use some reinforcing in my opinion though. Being afraid of tipping the stand over is not a good feeling when you want to rotate the engine on it.

 

[BodybyFisher]

Rock, The Northstar?

The crossover was off, but it wasn't a problem.  I'll post a photo

I have one on a stand in the garage

[rockfangd]

Oh ok. The crossover is still on mine. 

End Hijack

[CaddyShak]

On 9/10/2018 at 3:52 PM, Lance Johnson said:

I bought a new crate motor a 1967 Cadillac 429 that been sitting in storage for 2 years and now the motor is seized what is the best way to free the motor

I have had that problem on an unrelated stored engine, I took the spark plugs out and pumped a couple of ounces of WD40 into each of the spark plug holes, hand thread the plugs in a couple of threads.  Let it set a couple of weeks, and then the engine would turn over by hand with the spark plugs out.  Use high pressure air to blow out and clear out each cylinder. It doesn't take but a small amount of rust in each cylinder to stick the pistons from moving, but the WD40 will dissolve the small amount of rust and free up the engine.  After blowing out the cylinders with air, put a couple of pumps of new motor oil in each spark plug hole, and while leaving the plugs out, turn the engine over a few times by hand.  Now blow out any remaining motor oil from the cylinders, before putting the spark plugs back in.  The engine should be ready to start.