Hot Rods Help Removing pistons from block

I've got a 400HP 409 block with the pistons frozen in the block. What is the best way of removing them, I don't mind sacrificing them at all as long as I don't loose the block.. I guy told me that I can bust them out............

 

Acetone&ATF 50/50 mix and soak,vinegar,PB blaster.Patience x3.Coca-cola works too.

 

Ok just to let you know the skits are pitted bad too, as well the rust on top of two of the pistons has pocked the top real bad. I'll try the acetone and ATF over the next few months of soaking.

 

If they are that bad I don't think soaking will help a whole lot. On ones that bad I usually just bust a hole in the piston top with a sharp punch and then break the rest of it out instead of waiting on a solvent to remove something I will throw away anyway.
My 2¢

 

be careful not to damage the bores. if the pistons are really rusted then they are probably swelled up, so you need to break them up carefully, rather than try to drive them out.

 

Soak the bores with Mexican coca cola(old formulation)

 

would it be a idea to drill holes in the top if the pistons to relieve some of the stress?

 

Get a couple of 2 liter cokes and pour it in on the cylinders and give it a few days,then you can knock them out with the handle of a hammer.

BTW,I don't think diet coke works. HRP

 

You guys do know the active ingredient in coke is phosphoric acid, right? Why not skip the syrup and get right down to it with a diluted phosphoric acid/water solution? Is there any reason you shouldn't do that?

 

it won't relieve the stress, you have to cut all the way thru the edge of the piston, from top to bottom, to relieve the stress.

 

phosphoric acid does not go well with a burger and fries

 

I didn't work for me, I am still fat!

 

me too!!

 

the phos acid they sell in the rust removal stuff works good , so does dilute hydrochloric acid ( saved a 63 413 block this way ) , just do not smoke or light a match near it as the fumes are hydrogen and will make a nice bang , have to change the mixture ever 2-3 hours as the reaction nuetralizes the acids . I have drilled holes on both sides to get a sawzall blade down along side and cut a kerf in the piston and broke the skirt and they released have to do it 90* from the pin as thats the thinest point . have to be careful not to scratch the bore .

 

If ypu can get the crank out first do that and begin by driving the pistons down. Then use 50 or 80 grit sand paper and clean the cylinder walls of rust and whatever gunk you used to free the piston. Remove any ridge and try pushing the piston out.

 

I'll disagree on this. We have removed many EarlyHemi pistons by drilling through the tops and removing as much material as possible to reduce the hoop pressure against the walls/rings.
Obviously, great care must be used so as to not nick the cylinder walls, but with most of the piston gone it is easy to knock the rest loose with a hammer and drift.
The option is to soak the entire mess in a hot tank over the weekend and then change out the chemicals.

.

 

I think that's what I said....

 

Coke is probably cheaper. HRP

 

How about some pics, let's see what we're dealing with, just rings rusted to the walls or big bubbly rust areas on the walls with pitting. Soaking with any of the above mentioned, remove the main and bearing caps and oil the crank surfaces reinstall caps with loose torque, and throw a breaker bar on see if it will rock back and forth at all.

 

White vinegar let sit overnight and a block of wood smacked by a bfh

 

Ok I'll post photos Monday night. The engine is out at the farm

 

If you can drive the pistons down, use the grease-gun trick. It has never failed me.

fabricate a steel plate (1/4" or better) that you can bolt over a single cylinder, and put a zerk fitting in it. Fill the cylinder with grease- use a putty knife to get a slight overfill with no air bubbles. Install the plate and bolt it down tight. Hook your grease gun to the zerk fitting and start pumping grease into the cylinder. The grease will push the piston down. It takes a while and a lot of pumping and it makes a mess, but it works. I haven't wrecked a cylinder yet, but once in a while the ring lands on the pistons will break.

 

If the grease gun method sounds hokey.... an ordinary grease gun will give you up to 6000PSI. Multiply that times the area of the piston, on a 409 that is over 80,000 pounds of pressure!
Not enough? A high pressure grease gun is up to 15000 PSI

 

Full-strength muriatic acid will nicely disolve a piston.

 

Aluminum shrinks 3x as fast as steel when chilled. I've put dry ice on a piston top & it shrinks while the corrosion between the piston & block acts as a sort of insulator & prevents the block from chilling too quickly. I chilled the piston for just a few minutes, then wacked it loose with a hardwood block & 4 lb hammer.

This was after soaking in oil for a month, BTW, and still not being able to break it loose with the crank & flywheel tool.

 

For my flattie, i used atf, pb, and marvrel for soaking. Add a little Heat with a handheld lp torch and repeat.

Streetrods are drivin' by Chevy, Hotrods are powered by Ford!

 

Lots of Good Ideas Guys. I'll get photos and post later.

 

You don't have to fill the cylinder with grease; any fluid will work, although something thick like 140W gear lube will work best. This also make cleaning out the grease a bit easier...

 

...and have a buddy ready with the fire extinguisher, unless you're planning to barbecue.

 

This is true because fluids are incompressible. Even water could work.
Grease works well because it's thick & won't leak easily through any small ring gaps etc.

We did this on an engine, just by bolting the head back on without pushrods so all the valves would close. We welded a porta-power fitting to an old sparkplug base, then pumped plain hydraulic oil in.

Beware though, that this method could crack the head if you have a really tough case and a head with thin walls.