Frozen cylinder

[enerdome]

We have a 72 600 sitting in storage with pistons frozen in the
cylinders. we have tried all remedies for pouring liquids on top of
pistons to free them up. any "stealth" ideas on how to break them
loose? the engine is still in the car, and I am afraid to pull on
them too hard and wreck the pistons or break off fins.....
Thanks, Thomas

[Greg]

Use a block of wood and a rubber mallet to tap the pistons one at a
time while an assistant applies a turning force to the crankshaft.
As soon as one piston begins to move, and that will be only a very
small amount, s/he should be able to tell which way the crank is
wanting to turn. Apply a turning force in that direction and
continue to tap the piston crowns alternatively.

[dealadayray]

Hi Thomas,
Greg has one of the most used ways, I use Marvels miracle oil and some
kerosene mixed. Let it stand for a week, then with the shifter in neutral,
use a 17mm open end wrench placed on the bolt head (pulley side) and move it
back and forth. Since you already have the head removed then tapping it a
bit will help. If it does not break loose the first time then put some more
mix in and let it set a few days more. What has happened is the rings
(ferrous metal) and the cylinders (also ferrous metal) have rusted together.
The rings have movement in the pistons because they are non-ferrous metal
and won't corrode the same as steel to steel will. Because the rings are
most likely free or have some movement in the inner edges, tapping the
piston can cause them to break. So rocking the crank shaft is the better
way and if it moves just a bit, well that's the rings shifting. Get the
idea? Move the crank shaft to the brace the rings then tap a bit if your
going to tap on the pistons at all. You should get your pistons free in a
few weeks, depending on the corrosion.
Bill

[Miles]

I have had good luck several times to remove the 3 hold down bolts at
base of cylinders. Soak the cylinders with your favorite penetrating
oil (I use Knocker Loose, or Kroil). Use a 22mm open end box wrench
on the flats of the timing pulley, hold the cam chain taught so it
doesn't bind at the bottom, the cylinders will rotate up with the
pistons, and using the downward force of the cylinders slam them into
the top case- uhh, you might like to place some wood shims on top of
the cases. As the pistons slide out stack taller wood blocks in to
slam on.
If you beat on the tops of the pistons with wood blocks you will
actually expand the piston due to the dome and cause them to stick
worse.
Once the cylinders are off you may find the wrist pins are frozen
into the small ends of conn rods. If you try to beat the pins out you
will possibly bend the conn rods. I have had good luck securing the
piston to a stud then pounding the pin through. Forcing the pins out
also may scratch the inside of the conn rod and you will have to fit
oversize wrist pins.
There is actually a tool for extracting wrist pins from the pistons
and is usually cheap, I think mine was $20.00 or so.
Miles

[stony-treasures]

I have used an old spark plug base and made a fitting to connect to a
porta power hydraulic jack. Apply pressure and check frequently and
apply a little more each time the pressure goes down. I can take some
time to back it all the way down. I would oil the other side also,
when one side it down pull head and cylinder on that side reassemble
and do other side. It will force oil past rings as it forces the
piston down. I have not had to do this on a Honda but have on old hit
or miss engines that were considered junk. It's real cool when the
person sees the motor running that he sold you as junk.........
Tom

[Miles]

That would only work if the head was on and valves seat tightly
otherwise oil will flow out the valves.
Miles