I inherited a 66 automatic from my dad that has the small block. The engine is original numbers matching but is locked solid. I have pulled the plugs and am injecting marvel mystery oil into each cylinder weekly for the last month. Still wont budge even with a long breaker bar on the crank pulley. Also pulled valve covers and injecting MMO into the push rod holes. Plan to pull timing cover and timing chain to take the valve train out of the equation. Any other suggestions? Dont want to damage the block.

 

It's going to have to come out for a rebuild - save your self a lot of aggravation and unnecessary cursing by pulling the engine right now.

 

Maybe the Trans is 'frozen'...and keeping it from turning...

 

If you plan on using that motor it will need rebuilt so just pull it. If you do not plan on using that motor you will need to pull it anyway to install another motor so don't kill yourself just pull it.

 

If the cylinder walls are rust-laden you're performing an exercise in futility. You could use a borescope or goose-neck inspection camera down the plug holes to examine things.
I'd bet dollars to doughnuts you're in for an engine pull.

 

I know that will cost me at least a couple grand and will do that but was hoping for a magic answer. I have pulled engines before and they cause their own aggravation and cursing as well.

 

Borescope like FTF said.
How many miles on it and how did it run before it got parked??
Maybe just take off the heads to get the birds eye view into each cylinder.

 

The TV camera is a good idea.

A friend had the patience to work on a '53 Ford engine years ago that was stuck from sitting. He soaked it for a month with diesel fuel. One day, it moved just a hair and once he got it to move back and forth it was just a short matter of time he had it running.

The engine ran great for a couple of years until the car was destroyed in a wreck.

If you have a crank bearing seized, forget it.

 

yes pulling and rebuilding is a chore...but if you take the long route

end result over-rides the complications of using a sour seized one...once it's rebuilt the investment will provide a solid car and will then be usable and increase it's value and driving experience...the matching numbers is the best part...so as others have suggested rebuild your matching #'s small block you will be happy in the end...or advertise it here on the forum with pixs of car and be happy with no hassle of the rebuild

 

Interesting idea. Have never heard of a tranny being frozen but anything is possible. Car has not been run for 30 years. Thanks for the suggestion.

 

The old myth (maybe true) was that you could pour Coke in the cylinders and, given enough time, the carbonic acid would eat through any corrosion. So, you wind up with pitting in the cylinder walls and even if it starts you're delaying the inevitable most likely.

If you post your location somebody nearby may have an inspection camera...if near Orlando you'd be welcome to borrow mine. Harbor Freight has them for $70. I use it to inspect frames, hinge pillars, plumbing inside walls, dryer vents and amateur proctology.

Considering that last use, you may not want to borrow mine

 

This happened to me once. My car sat for perhaps 10 years and then the engine would not budge. DO NOT ATTEMPT TO TURN IT OVER WITH THE STARTER!!! The starter will engage and try to turn the engine over. But when it can't, the starter might not disengage. Even when you turn the key off. Then the starter will get hot and start to smoke. Now you have a problem. You must disconnect the battery while the cables are red hot and smoke is pouring out of the engine compartment. Another reason for the green ****.

I got lots of Marvel Mystery oil in the cylinders. Then I took the clutch cover off to get at the flywheel. With a tire iron, I pried on the teeth of the flywheel (ring gear) against the bell housing and slowly got the engine to move. Over the course of a few weeks, I moved the flywheel a little in each direction more and more. Finally I got it to move 360 degrees. Then I spun it good with the starter. (OK, a new starter.) You must be careful with the ring gear teeth and the bell housing edges when you do this.

After I freed up the engine, I ran it for years, and it ran good. It did not blow smoke. I sold this engine with about 15,000 to 20,000 miles on it. The buyer took it apart and discovered that the pistons and the cylinder walls were severely pitted - probably from rust. I, of course, refunded his money. But what I couldn't understand is how the engine could run so good and not blow smoke when the cylinders were so rusted. So my point is that even though your engine may be seized from rust, you may be able to free it, and it may run just fine afterwards despite being in bad shape.

If I had to do this again, I'd buy a borescope (digital inspection camera) from Harbor Freight for $70 and look at the cylinder walls. If I didn't want to pull the engine, I'd try to free it up with it in the car. But if I wanted to accomplish some other tasks only made possible by removing the engine, I'd pull and rebuild the engine. When I did mine, I didn't have the time, money, or inclination to remove the engine. I was younger then, and didn't mind so much doing jobs twice. Now that I'm older, I take the time and spend the money so that I'm sure I won't have to do them again.

 

I freed up my 66 327 L79 last year, it turns free today after 35 years sitting.
I found the mix of 50/50 acetone and automatic trans fluid worked best.
Mine was found to have mice living in two cylinders so I pulled the heads before it finally broke loose. These two pistons are pitted badly but now rotate smoothly.
Took me a couple days starting with a 3 foot breaker bar but now rotates smooth like a new engine. I still plan to pull and overhaul mine before running it.
The 50/50 mix is proven to be the best rust remover.
I filled an old oil container with the mix and it comes in handy on rusted bolts as well.

 

How on earth did they get in?

Expiring minds want to know.....

 

I think that your dilemma is not knowing why it's stuck and the results of going one way or the other to try to get it unstuck.

If it's truly FUBAR, you'll waste time trying to get it unstuck, and it will need to be pulled and rebuilt anyway.

If it's only part FUBAR, you might get it unstuck, and it might run okay for awhile, and maybe even run decently well for some time. But, you might permanently damage it, resulting in trashing the numbers matching engine for this car, which is a non-recoverable money loss.

If it's not FUBAR in the least, you can save a lot of time, money, and effort by getting it unstuck and drivings it; however, if it is stuck so hard that you're having to put significant effort into trying to get it unstuck, what are the chances that it is not truly FUBAR.

If the rods or the crank are broken and bent, and you turn it, how do you avoid destroying the engine? I would at least pull the oil pan and take a look, and pull the heads. It's cheap insurance.

 

The 396in my avatar pic had mice living in the cylinders too. No carb on the engine so I guess they went down the intake through the open valves. Completely trashed the block. I think mice **** is like acid. Had to beat the pistons out in pieces. Required boring to 90 over to clean it up. Probably not worth it in the long run.

 

Sounds like you've done the right steps.
Mine sat for 30 years and was OK - bumped it in gear and saw the motor turn.
Coolant was drained but oil was left on mine - maybe that helped??

Remember, there is productive cursing and non-productive cursing!

 

What are your long range plans for the car?? Keep or sell?

I would bet you can get the engine free with patient soaking and movement. It may run fine for a long time if you only drive it occasionally on short trips. Will the car roll in Neutral? Pump up the tires and get some buddies to push it back and forth and see.

 

I like the borescope idea and taking the trans out of the equation. Easy enough to unbolt the torque converter from the flex plate. The best penetration oil can be made from ATF mixed 50/50 with acetone. That might free it up if the cylinders aren't rusty. It may take weeks. I have seen a few older engines brought back to life this way without teardown. The odds are against you, but it may work out. Whatever you do, don't force it....but it sounds from your posts that you already know the right technique. Good luck, and keep us posted!

 

My boat had a 350 Chevy Mercruiser engine in it. It sat over the winter with rain water coming in through the tonnuea cover. Never mind how/why.

Memorial Day coming up and the thing won't start and I didn't know that one cylinder was full of water. 24 volts on the starter and me standing on a two foot lever on the crank pulley would not budge it. I pulled the engine. Went in through the pan and got a driver bar with a five pound sledge and drove the stuck piston out the top of the bore. A new piston, rings and a quick pass with a dingleberry glaze buster and I was on the water running fine for 10 more years before I got rid of the boat.