Packard Forum Index » V-8 (1955-56)

Well I finally started to do some work on my 55 clipper engine. The number 7 piston is rusted fast in the bore. I tore down the engine this weekend and was able to remove all the other pistons. The crank has some serious rust/pitting on the main and rod journals. Anybody have any suggestions on removing the piston. I poured a can of coke in the cylinder on Sat and tried tapping on it yesterday evening with no luck. Here are some pics.

Sometimes in that situation, only a BFH (sledge hammer type) and BFP (steel punch) will get it out. In other words, you have to break up the aluminum piston to get it out. Try not to bang the cylinder wall, although the rust has probably messed it up pretty good already.

Of course, a cutting torch or cut-off wheel is an alternative.

Also, get it out through the top of the cylinder, not the bottom.

Craig

Thanks Craig. I'm going to give it until this weekend and then start really beating on it.

Pour a mixture of ATF/diesel on it and let it sit for a couple of days. It may penetrate enough to loosen up the rust and let the piston break free. I would let this sit outside away from the house since it is a flammable mixture.

Kev, we'll make a chemist out of you yet. Combustible, not flammable.

Take it to a shop that has a chemical tank for cleaning engines, most of those cleaners will eat away anything non-ferrous, leaving only the cast and steel parts.

THis is something that should be done BEFORE the engine is dissassembled.

Put hte head on with the old gasket. Put the crank back in. No need to torque the crank real tite.

Pour in some snake oil. Place 100 -150 PSI air pressure into the cylinder thru the spark plug hole. Keep the pressure on it for about 2 or 3 days it will break loose.

The OEM V8 pistons are rare as hens teeth. Try to save it. Use the compressed air trick outlined above. Works everytime for me.

There is another method that has been used with success on much older engines than yours.

Make a plate to bolt on the top of the cylinder. Drill a hole and put in a grease fitting. Fill the cylinder with oil or grease, bolt on the plate, and start pumping it full of grease from a grease gun. This will provide up to 3000 PSI of hydraulic pressure. Enough to push out any piston without damage.

Basically the same as the air pressure trick but more powerful. Try the air pressure first, if that does not work try the hydraulic pressure.

The problem with the pneumatic or hydraulic method is that it will not remove all pistons on all cylinders. On a Packard V-8 block, only #1 & #8 cylinders are completely open on the bottom. The other six are squeezed in on one side by the main webs. You need to remove those out of the top.

I like Eric's method (chemical tank) as a step before my brute force method. But, because of EPA rules, many automotive machine shops have gone to the furnace method of removing old rust/sludge/etc.

Craig

It's been my experience that forcing a stuck piston down like the methods described here virtually ensures cylinder scoring from stuck rings.

Gentle persuasion and finesse wins over brute force every time.