STUCK pistons ADVICE

Posted By: mro

STUCK pistons ADVICE - 02/06/10 07:11 PM

I've got to break the pistons out of a 383 - Assuming the rings are all stuck - I have no intention of re-using the pistons - would like to save the rods if possible - the caps are off the rods and crank but the crank is stuck because all the pistons are frozen in place - the block is important to the care ( numbers) Any ideas to make this as easy as possible? AND is anyone making 383 pistons 10:1 comprssion .30 over? Thanks!!!!

Posted By: 6pkaar

Re: STUCK pistons ADVICE - 02/06/10 07:18 PM

I've never tried it, but have heard of guys pouring a can of Coke over the piston and let it soak for a day or two. My uncle messes with antique tractors and has freed up several stuck motors using this meathod.

Posted By: RapidRobert

Re: STUCK pistons ADVICE - 02/06/10 07:21 PM

Put some diesel fuel or kerosene on top of them for several days. Worst case scenerio might have to drill a bunch of holes in each piston top to free up the piston walls. Would be time consuming but with it being a #'s matching block I wouldn't do much pounding on the pistons. When you get it rescued you'll soon forget about all the labor it took but if you crack the block you'll be upset for a long time.

Posted By: AndyF

Re: STUCK pistons ADVICE - 02/06/10 07:28 PM

Just bust them out of there. Use a steel rod up from the crankcase and hit it with a 5lb sledge hammer. Cast pistons will easily bust. You can usually only get a few pistons at a time so you have to work your way around the block. Hopefully you can bust the stuck ones and then rotate the crank enough to get to the next ones.

Posted By: mike s

Re: STUCK pistons ADVICE - 02/06/10 07:29 PM

1.)Mopar rust penetrant.Soak each cyl several times.It will eventually free up.
2.)A few shots with a dead blow hammer should help.
3.)If 1 or 2 doesn't work if may be neccesary to break the top of the piston.

Posted By: Snoopy

Re: STUCK pistons ADVICE - 02/06/10 07:52 PM

If the penetrating oil doesn't do the job. Pool acid, muriatic acid. Dilute some muriatic acid and pour it between the piston and the cylinder wall. Wait about ten to fifteen minutes and then pour some water/baking soda solution over the piston to neutralize the acid. Then drive the piston out. The pistons will be a total loss.
You are probably going to bore the engine, I wouldn't worry about damaging the cylinder wall with the acid.

The acid does two things, dissolves any aluminum that may have fused to the cylinder wall and dissolve any rust between the rings and the cylinder wall.

Be careful, the acid is not user friendly. Use appropriate clothing and a safety shield. You don't want this stuff on your skin, eyes or clothing. Keep a bucket with water/baking soda solution handy for accidental spills or splashes.

Posted By: Reggie

Re: STUCK pistons ADVICE - 02/06/10 09:20 PM

If you're in no rush you can also try plain ATF. Pour enough in to cover each piston completely and let it sit.

Posted By: 500ciDuster

Re: STUCK pistons ADVICE - 02/07/10 02:19 AM

I've soaked with whatever then take a 2x2x4 chunk of wood on end beat with a maul on intake side and exhaust side of pistons,once u get the to rock a little they will come right out.Another way I got them to move was with a hydraulic bottle jack and log chain, put the bottom of the jack on top of the piston wrap the log chain around the block & over the ram then start jacking(if you are accident prone don't do 2nd one)

Mitch

Posted By: BSB67

Re: STUCK pistons ADVICE - 02/07/10 02:28 AM

Quote:

Just bust them out of there. Use a steel rod up from the crankcase and hit it with a 5lb sledge hammer. Cast pistons will easily bust. You can usually only get a few pistons at a time so you have to work your way around the block. Hopefully you can bust the stuck ones and then rotate the crank enough to get to the next ones.

Big

This is what I used last time

Attached picture 5787484-DSCN6201.JPG

Posted By: JohnRR

Re: STUCK pistons ADVICE - 02/07/10 03:56 PM

you need to be careful just busting them out , a friend punched a hole thru a cylinder wall doing it that way once .

As far as your 10.0 .030 piston request , the only piston that will get you that is the KB400 DOME piston , the factory OVERATED the 383 , the only way to get that compression ratio with a flat top piston is to deck the block so the piston is poking above the deck .020 and using a cylinder head with a 79.5 cc chamber with a steel shim gasket ... assuming 906 open chamber heads ...

Posted By: 4BBodies

Re: STUCK pistons ADVICE - 02/07/10 05:05 PM

I find a piece of cut firewood the closest diameter, and hit that. It spreads the force over the top of the whole piston, and keeps from damaging the cylinder wall with the hammer. Works pretty good! But you have to soak it for days first, usually I use diesel fuel.

Posted By: 70gtx440dana

Re: STUCK pistons ADVICE - 02/07/10 06:48 PM

Lots of good advice here....I freed up a 440 by using PB blaster rust penetrant, a 5 lb. maul and a stack of hockey pucks taped together to beat on. Cut a hole in small piece of wood just larger than the bore dia. to protect the top of the block in case you miss the hockey pucks. Worked for me and all of the pistons were stuck. Good luck!

Posted By: 1970mopar

Re: STUCK pistons ADVICE - 02/07/10 07:01 PM

Take it to your local engine machine shop and have them quote you for the job. I bet they will be able to do it for less $$ than you think and you won't have the issues of possible damage trying to do it yourself

Posted By: 69MOPE

Re: STUCK pistons ADVICE - 02/08/10 01:00 AM

Quote:

Take it to your local engine machine shop and have them quote you for the job. I bet they will be able to do it for less $$ than you think and you won't have the issues of possible damage trying to do it yourself .

It's going to the machine shop anyway for the .030 bore!

Posted By: RapidRobert

Re: STUCK pistons ADVICE - 02/08/10 01:08 AM

Quote:

Quote:

Take it to your local engine machine shop and have them quote you for the job. I bet they will be able to do it for less $$ than you think and you won't have the issues of possible damage trying to do it yourself .

It's going to the machine shop anyway for the .030 bore!

Be sure & tell THEM it's a valuble block and not to beat on it as they could very easily delegate that job to the lowest man on the totem pole and the BFH might appear (to him) to be the appropriate tool for the job.

Posted By: @#$%&*!

Re: STUCK pistons ADVICE - 02/08/10 02:00 AM

The only tip I can add to the above is to clean the bores above the pistons with some coarse sandpaper before starting. If you don't do this they'll fight you all the way out and require lots more pounding with the bfh.

Posted By: StandOnIt

Re: STUCK pistons ADVICE - 02/09/10 04:26 AM

Diesel fuel works well. I got some out with Kroll penetrating oil also. I agree with lightly sanding the cyl's above the slugs so the will come on out once they are free'd up. A hammer and a piece of wood to work them around in there. Good luck with it and just take your time.

Posted By: 72dak

Re: STUCK pistons ADVICE - 02/09/10 11:38 AM

ive dealt with alot of frozen engines and the best luck ive ever had was with pb blaster. make a pool on top of each piston and let it sit for a couple hours, roll it over and try to pound them
out using a wooden dowel or hammer handle. if some still dont move, dont rule out frozen wrist pins, i had a locked up 383 because of 1 frozen pin. if this is the case fill the bottom of the piston while its upside-down and try again later but be careful for cyl. damage as the rods may not move smoothly. good luck

Posted By: LS-300

Re: STUCK pistons ADVICE - 02/09/10 04:27 PM

May sound strange but the last one I incountered my Grandfather showed me how to get it out. We went out and got some Dry Ice. Remember handlying with caution. Packed above the piston with it and covered it over with a section of plywood. We made a piece of wood as close to the diameter of the cylinder as we could. After a short with using the wood block we made and a hammer we pounded it down out the bottom of the block. Didn't take much work and didn't damage the block. Shocked the snot out of me but he did this a lot on trucks that he rebuilt.

Posted By: Crizila

Re: STUCK pistons ADVICE - 02/09/10 04:33 PM

Quote:

May sound strange but the last one I incountered my Grandfather showed me how to get it out. We went out and got some Dry Ice. Remember handlying with caution. Packed above the piston with it and covered it over with a section of plywood. We made a piece of wood as close to the diameter of the cylinder as we could. After a short with using the wood block we made and a hammer we pounded it down out the bottom of the block. Didn't take much work and didn't damage the block. Shocked the snot out of me but he did this a lot on trucks that he rebuilt.

Cool ( pardon the pun ) idea!!!

Posted By: HotRodDave

Re: STUCK pistons ADVICE - 02/09/10 06:55 PM

I agree about cleaning the bore above the piston, also if you can tap it down about a 1/4 inch and clean above where the rings have been sitting and then drive them back out it can be pretty easy even on a really bad motor.

Another thing that worked for me on a really bad 340 was to take all the rod caps off first and pull the crank, then put the caps back on the rods and hit them with a dead blow hammer.

Really good penatrent is important, let em soak for a good long time.

On a couple of the pistons I ended up drilling holes and busting them out a little at a time.

The worst motor I did was that 72 340 and it had cast pistons and they are tougher than you would think when you are just trying to bust them out, the pesky steel strut cast into them is a real pain

Posted By: 71sat440

Re: STUCK pistons ADVICE - 02/09/10 11:00 PM

Warning I have never tried this on a car.
I am learning blacksmithing.
When a piece of metal is heated in a forge the carbon content comes to the surface as forms an ultra hard layer.
So hard it destroy hand files easily.
If soaked in vinegar you can wipe the layer off easily with a towel.
Leave it to long and it will get very fine rust.