O/T - Sorta... Pistons Stuck in Bores

[BigNate]

I guess it is kinda FE - in that the engine in question is an FE... so...   

Anyway - I have a D2TE based 390 that I bought for the block.  I paid next to nothing for the long block (either $25 or $50 if memory serves) and did not do much if any inspection on it before hauling it home.

Anyway - it looks like the rings are rusted to the walls.  I've had Marvell's in each bore for the last few months.  A month or so ago I checked and they were still solid...  If memory serves the block was already either .020 or .030 over.  I've never dealt with this before - so I've got a few questions...

What I've done so far is....
* Pull the heads... find rust / water in a couple of holes...  dried the block out, filled each hole with Marvell's Mystery oil... 
* Attached an old fly-wheel and made a make-shift lever with hooks for a couple of holes in the flywheel - and then proceeded to hang my 300# butt off the end of the 4ft lever - with no luck...
* Pulled the crank (the journals look surprisingly clean) flipped the thing over and gave the top of the offending pistons a decent tap with a soft faced dead-blow hammer... no joy....
* Grabbed a 12" chunk of 2X4 and used it as a big soft punch - whacking it with a 16 oz framing hammer... no joy...
* Tossed the 2X4 and grabbed a 3lb sledge hammer...  decided that while I did not care about the pistons or rods... I didn't want to do something stupid and ruin a potentially otherwise good block...

SO....

1) What are the odds that the rust at the rings is so deep that the bores are shot to the point that a typical 390 block would not take more over-bore?  I can do the "drill bit test" on the block (need to pull the freeze plugs) - but candidly don't want to mess with it if the answer is "yeah when they get that rusted the block is scrap"
2) If the block is not likely scrap - how gentle do I need to be with this deal?  I am not interested in the pistons - but don't want "aggressive piston removal" to result in unnecessary damage to the block.  I've thought about hitting the pistons with a 3 lb sledge, a 12 lb sledge, or possibly mocking up some sort of flat surfaced attachment for an air hammer and going at the piston with that.  I even gave some thought to mocking up some sort of structure that bolts in to the head bolt's home - and having at the piston with a porta-power...

Advice?  Do's?  Don'ts? 

thanks in advance...

Nathan

[blykins]

Well, the way I look at it, you really don't have anything to lose.  You can't use it the way it is and there's no way of seeing what you have until you get the pistons out.

I would take a piece of wood and a 3 lb hammer and try to drive them down instead of up.  If there's rust and ridge both, that could really make things rough for you.  Just try to drive the pistons and rods down towards the crankcase.

[Rory428]

If moisture got inside the cylinders, chances are the pistons are corrodedand stuck in the cylinder walls. I have had them stuck bad enough that I had to cut the connecting rods, to save the crankshaft. Soaking the cylinders for weeks with oil and ATF did not free it up at all.Block was junk.

[machoneman]

This works, if you have the engine out of the car:

http://forums.sohc4.net/index.php?topic=84354.0

[jmlay]

I was going to say flip the block over & Marvell the bottom side of the pistons but Bob's solution look more promising .

[BigNate]

Thanks much all...

jmlay - I should have mentioned - I have rotated the block over and let Marvell's soak in the bores from the bottom as well...

mackoneman - I didn't mention it above cause I didn't want folks thinking I was nuts - but I thought about hitting it with a rose-bud for a while - but was afraid of the damage to the cylinder walls from the extreme heat.  I'm thinking that I'll escalate one notch with the hammer - and then give the suggestion you posted a shot.  Thanks.

blykins and Rory428...  thanks - I guess you are right - either the block is shot or it isn't.  I'll get them out of there somehow and find out...

[machoneman]

Hang in there Big Nate! You'd be surprised how often the block is still good even after beating out old, stuck pistons. Just be careful not to hit machined surfaces (deck, main bearing bores, etc.) with a steel punch or hammer.

[thatdarncat]

And if all else fails, breaking up the pistons by any means.

[MT63AFX]

Thanks much all...

jmlay - I should have mentioned - I have rotated the block over and let Marvell's soak in the bores from the bottom as well...

mackoneman - I didn't mention it above cause I didn't want folks thinking I was nuts - but I thought about hitting it with a rose-bud for a while - but was afraid of the damage to the cylinder walls from the extreme heat.  I'm thinking that I'll escalate one notch with the hammer - and then give the suggestion you posted a shot.  Thanks.

blykins and Rory428...  thanks - I guess you are right - either the block is shot or it isn't.  I'll get them out of there somehow and find out...

Your concern about using a torch may be unwarranted. Cast iron blocks are poured at about 2,800+ F and ignition produces a higher temp. If all else fails maybe try melting the piston out by burning about 1/2" from the cylinder walls to burn the center out. I see no one mentioned the "melted candle trick",  , jmo, Rod.

[wayne]

Try this it has worked for me many times put a bell housing bolt in the block. Then use a jack handle in the ring gear teeth wedge the handle against the bolt .You will have a lot more leverage like a starter.

[BigNate]

Thanks all... I'm going to make another run at it this weekend.

[Qikbbstang]

 are dealing with eight pistons/cylinders all connected via the crank. Everyone knows it is impossible to unbolt all eight rods and drop pistons out w/o rotating the crank. At most when things are seized you can get at the rod nuts and have a straight shot at driving the piston out of one or two cylinders. You can also hammer the rod bolts out of the rods to gain extra clearance. If all pistons/cylinders are frozen you have a nightmare. I never had a really hard seized motor but I think a cut-off wheel could cut through rods like butter and allow the crank to be taken out. Once the cranks out a 4"x4" and a sledge could provide shove. One thing I always wondered about is just like tree roots cracking a driveway and ice cracking a block the growth of corrosion of cyl walls and pistons may provide enough expansion by themselves on the bores to crack them. Ditto forcing a corroded piston through a corroded bore could that crack a bore. A drill could be used to stress relieve the pistons . I have a high end electric die grinder and that could really weaken pistons in a hurry.

[My427stang]

I am not sure if it would do a thing, but I have used Evaporust on some very rusty stuff and its almost magical

Water based, cheap, available at the mega hardware stores, disposable down the drain...

Takes 24 hrs, but you could fill 4 bores, let it sit overnight, roll it over, do the other.  Might weep its way down and make it loose enough to push the pistons our   Typically I am not a chemical guy to solve my problems, but this stuff is pretty slick

http://www.theruststore.com/Evapo-Rust-P1C21.aspx?gclid=CNSqntWX-7oCFSvl7AodZkMAWQ