smashing out stuck pistons

Is there a better way of doing this then continually smashing at these ? have to go through the top - the crank is stuck in place.

What engine?

I don't think pistons can be taken out thru the bottom on very many engines.

Pour some Winter Green on top of the pistons/around the rings, let it soak for a few days, pour in more Winter Green as it might drain away past the rings.

Turn the motor upside down, pour in more Winter Green, let it sit for a few days.

Then pound away from the bottom.

383 RR 69 - I could swear I took the 392 pistons out through the bottom - it was years ago - I could be wrong

I only know of a couple of chev engines that only a couple of pistons can come out the bottom, BUT the crankshaft has to be removed beforehand. Soak it bigtime I guess.

Its been soaking in kroil for 7 years....no joke - really. Its the original engine to one of my cars that I am not using - but i'd like to send it out for a rebuild. 7 years of soaking - thats seriously stuck

I had to break the pistons out of a 440 that sounds similar to your situation. It takes awhile.......big hammers and chisels. Not fun!!!

Start on the worst looking ones. After you get a couple out you may be able to turn the crank!

I think pouring molasses in bores will free it up.

Molasses eats the rust. Get it at farm supply stores in a big drum, soak the whole block.
The vinegar, salt, and lemon juice mixture eats aluminum so that may be even better in a case like this where the Pistons are junk.
Does pounding the Pistons to death cause any damage to the cylinder walls or block?

I'm going through the same thing right now, motor has been sitting since 1976 but is the matching numbers block to my car. I have had it soaking for over 4 months and no luck. we decided this weekend they are coming out one way or another, drilling, chiseling, or what ever it takes. I have to get started on my motor.

Knock them out from below using a long rod or pipe. Just get the pipe pushing against the bottom of the piston crown and then pop it hard with a 5 lb sledge and the piston top will break off. Only takes a couple of seconds once you get the hang of it.

Throw the block in a hot tank... All the aluminum will mysteriously disappear! Haha!!

soak in transmission fluid beat out with wood hammer handle

Drill multiple large holes in the pistons to make it easy to bust them out. Once they are out you can concentrate on the crank.

If you have to break them out, riddle them with holes with a drill to lesson the forces on the cylinder walls and make it over all easier.

Dang, got me by a few seconds...

I've never tried it and don't know how safe it is, but what about melting the center of the piston with a torch?

The heating and cooling should break the rust even if the whole piston doesn't trickle out...

Just me I would not want to chance cracking a cyl wall so I would go to town with a drill as to not risk any cyl wall damage. But I ain't been in that position so jmnho.

Do you have a way of heating the block (like in an oven)? The expansion and contraction may loosen things up. Just make sure there are no flammable liquids still in the block.

If your going to send it out to be rebuilt, why not have the machine shop do it? Yes it will cost money, but it may be better than damaging it trying to get them out yourself.

Drop the wrench and step away from the engine... sorry but from what I am reading you have NO idea what you are doing.

If you have cast pistons, this way works well. When I was a kid and made money selling scrap cast, every junk dealer would dock you half the weight because of the aluminum pistons. Removed literally dozens of pistons this way and I can't remember the block being damaged on any of them. Never encountered forged pistons but I would bet you couldn't use this method on them.

I'll go with wrong ...

Be careful smashing out those pistons , I tossed a 68 440 HP2 block because a friend smashed out the pistons , and smashed a huge hole in one cylinder wall.

Get dry molasses and a big tub and soak it in it for a few weeks ...

Kroil is useless for something like that .

I had a 400 that was stuck , but the crank wasn't stuck , i put it on an angle and sprayed PB blaster on the tops of all the pistons after hitting the walls with a wire brush on a drill to remove the scale. did one side then the other , long pipe on a breaker bar and a brass hammer hitting the tops of all the pistons I could reach and I got the thing to spin over. rust was only above the pistons though.

It was a 230 block but still needed 5 sleeves due to pitting and core shift.

Next to impossible, if not impossible, to find those type hot tanks anymore thanks to the EPA...

Plus I don't think the owner of said tank wants his solution trashed ...

Yep, knocking the tops off the pistons from below is quick and dirty. I will say that any engine with rusted pistons is probably junk though due to pitting. If the block is worth the money you can probably sleeve it but check the water jackets for rust. Usually if the cylinders are rusted then the water jackets are trash also.

yella 71 - dude - I am so clueless. ya see - I thought this was a place where I could ask questions and get answers. You ever want to match car collections let me know...champ

John RR, I did cracked and sleeved 2 years ago smashing the hell out of it - exactly what i'm trying to avoid

MRO you are doing great, post all you want/whatever you want. this is where we solve problems/dilemmas. EDIT the bore(s) may need drastic overboring and or sleeving but at least getting the pistons out WO damaging the bores is good procedure/mindset. (keeps Mr Murphy at bay). I would sharpen a bit & get after it.

Thanks - finally building/finishing my 69 RR after 13 years of metal work and body work. Went slow because of my job. Anyway - I did forget a lot of stuff on these cars from when I was younger - but not everything.

Here's how I got the pistons out of a Mercedes block that had had a head gasket leak and the ethylene glycol had literally glued the pistons in.
Before starting, the crank has to come out.
First I got a chunk of aluminum the same size as the bore, placed it on a piston top and gave it a couple of hearty whacks with a 2 1/2 lb hammer. The piston moved but was in no way going to come out. So,
I got a piece of 5/8" rebar and turned the block upside down. Placing the rebar inside the piston skirt, I knocked the tops out of the pistons. IMHO someone who gets into the cylinder walls doing this is either unlucky or careless.
Turn the block over and thread a length of small diameter wire rope around the wristpin, and out the top. Here's the tricky part, I used a hollow piston hydraulic jack and was able to run the wire rope through the center, clamp it on top.
Then I jacked the pistons out.

The first oversize is 0.5mm or 20 over. I bored the block myself at a high school auto shop and then had it finish honed with a Sunnen power hone. After the cylinders were honed to fit the pistons, there were still some small grayish-black pits visible. I put the engine back together and it runs great.

At that time, 1979, a new bare block was $1300. So I had no desire to bore any larger than I had to. Never had another problem with that engine. BTW, that engine had a forged crank and every journal showed the signs of being induction hardened. It was way too complicated but that engine was beautiful inside.

R.

I've never had to jack the pistons out after knocking the tops off. Those must have been really stuck in there. On all of the locked up Mopar engines I've worked on the assembly frees up once I've knocked a couple of pistons out. If the engine was store with the heads on usually only one or two cylinders have open valves and rust in the bore.

"smashing pistons". Sounds like a band name from the '90s.

My strategy has always been to just beat the almighty living crap out of them any way I can and somehow they come out.

Handheld air chisel?

Taking a short j bar to them with a sledge - I know they will need sleeves. I like the idea of drilling reliefs. ThANKS for all the input. m

I had a very rusty engine last summer that I went through this with. It soaked for 3-4 months in and out of the molasses bath as parts SLOWLY came off. After everything was off the engine except the crank, rods, and pistons I tried everything to get the pistons out. A couple did come out with the hammer and a heavy rod, driving them out the top. In the end after several weeks of trying I ended up pulling them out. I drilled a 5/8 hole on each side of the wrist pin, opposite of each other on the end of the pin and dropped a 1/2 wire rope cable down around the pin. A cable clamp to tie the cable together, a block of wood, a large pipe and a 20 to short bottle jack pulled them out of the holes. I put pressure on 1 at a time with the jack, heated the cylinder the best I could through the soft plug holes and used lots of ATF/acetone mix. I would give the jack a couple of pumps each morning before I would leave for work, come home and put some heat on it and give the jack another pump or two, what ever it would take. Some holes took 2-3 days before they came out, but every day you could tell they were moving. I did not hurt the bores in the block.

Interesting thread.
I have a 68 TNT 440 with stuck pistons.
I thought it was junk.
I recently read an article on this and saw a
couple pictures of holes drilled into pistons.
Not much mention of ring ridge removal.
Is it not an issue at this point?
Lots of good advice and alternatives here.
Gives a fella hope.
Thanks guys.

I would for sure would use it first IF I took em out as is.

The hammering isn't going so well. I may not have the hang of it -
though...but none seem to move - the backstory - this engine came with one of my RR and it is numbers matching....the reality after thinking about it is it might have been a junk engine anyway. My thought was to have it rebuilt - and put it back in. I mean - the original owner must have pulled it for a reason. Anyway - I beat it last night - NOTHING MOVED...outside of my shoulder. And the engine in the car will probably stay there. I figured the rebuild to stock would be 3500 - start adding removal and sleeves - it will escalate quickly - and for what ? Just thinking - I don't know. Not sure.

You can't get any pistons out? You should have a least a couple of pistons near TDC at any one time so work on those first. Take the rod caps off and tap out the rod bolts so you don't scratch anything and then pop those pistons from below. Once you get those guys out move on to the next couple of pistons that you can get to. Once you get 3 or 4 easy ones out you might be able to rotate the crank and get the next ones out.

I thought the same thing - none moved.

Will go try again right now - i have about an hour to work it

I am visualizing a multi-ton hydraulic floor jack with some type of arrangement with a chain to strap the block to the jack,,,or some other mechanism to make it immovable,,,and a very stout metal (metal pin or some such) held against the pistons from top or bottom. And the other end against the jack pedestal.

Something like placing block onto a hydraulic press and pressing them out. Have no idea how to manipulate and manage a block of several hundred pounds onto a press,,,,perhaps possible using a cherry picker,,,or perhaps the heavy duty jack idea may do it. Under extreme pressure and a few well placed slams with a big hammer may work things loose.

As I said, just visualizing.

Don't give up.

Likely you have checked out all the heavy duty liquid wrench type products. There are a wealth of them. I have often read of auto transmission fluid mixed with acetone that some swear by.

Sounds like a trip to the ER just might be in the mix here.

I have and idea that might work, as with bearing races that you can't drive from behind for one reason or another.

Drill a large enough hole in the center of the piston to get a hacksaw or Sawsall in and carefully work your way to the perimeter of the piston, use a hand file or hacksaw blade to do the last few thousands so you don't mar the cylinder walls.

With the piston's integrity thus diminished, it may free up the circumference and release itself??

Good luck, I'd really like to get my nose in there with you as I love a challenge, Joe

I like the idea of the bottle jack sitting on a block of wood across the bores. That is the easiest and safest method I've seen in this thread.

It uses the strength of the piston by pulling on the piston pin.

Now that's funny, the idea not if it actually happened.

OK - I really actually beat the living hell out of one. It moved about a 1/16 - or at least thats what it looks like between the rod and crank. Probably not a great question but it there a way of cutting the connecting rods without destroying the cylinder walls ? If I can remove the crank I can hit these right

The pitting on the lower walls is horrible. This might all be a waste O time.. will post a pic

This, and what Andy said earlier.

I've had pistons that I could not remove with a 2 ton hydraulic jack but I could beat out.

If you have not hit it hard enough to bust out the piston top, you have not hit it hard enough. You have to use a sledge hammer, unless you are a really big guy that know how to swing a 3 lb hammer.

I have used an acetylene torch to cut the connecting rods on a 383 to get it apart.

Good bar. Bigger hammer. You will get it.

Wont lye dissolve the aluminum? 55 gallon drum with the block in it for a week or two...or more

You guys are overthinking this. It isn't brain surgery or rocket science. Take a small steel rod or a piece of pipe and a 4# beater, go from the bottom and take the tops out. The rest will follow.

Got my pistons out today. Here is carnage.

As long as you did not hurt the cylinder wall you may be able to use that block....of course aluminum melts at 1270 degrees, so you could have just melted them and had some puddles of aluminum to play with or maybe make some new pistons...

Once the tops were knocked out the pistons came out real easy.

Cylinder walls look perfect.

A voice, crying in the wilderness.

Thats great and I see no signs of blood on the floor.

Nice batch of.... destroyed pistons ya got there.

Yes it's a miracle as one time I lost a finger tip pulling a motor out of a car by myself.


Think I will keep one around for a conversation piece and when they asked what happen I'll just say too much NOS and blew the top of piston off.