<VV> Freeing a stuck motor.

[roboman91324 at aol.com]

Ignacio,

 
I have worked on more than a few motors over the years and some have been seized.  The worst was a turbo motor for my '66 Corsa.  
 
First, to explain the comment about the square inches and piston surface area.  If the piston's surface area is 8 square inches and the air pressure is 150 PSI (pounds per square inch) the total force on the head of the piston will be 8 sq. in. x 150 PSI = 1200 pounds of force on the piston.  Assuming all 6 pistons are seized (a good assumption) 1200 pounds will probably not do the job depending on the severity of the seizure. In addition, you will only have a chance at success if you choose a piston that is approximately in the middle of its travel in the cylinder.  If the piston is at the top or bottom of travel, air pressure in the cylinder will have no effect.  The connecting rod bearing journal must be at a right angle to the force applied to allow the piston to have the major torque on the crankshaft and allow the system to move.  Take off the oil pan and/or top cover to see which piston to use.  Matt suggested removing the rockers to guarantee the valves will be seated.  If a valve is even a tiny bit open, the air pressure will escape.
 
Here is my ordeal.
 
I bought the motor to replace an incorrect 140 in my Corsa.  It came from the factory as a Turbo car.  I didn't look at the motor before I bought it because it was in Chicago and I am in LA.  The numbers on the crankcase indicated it was proper for engine type and date of manufacture for my car.  I trusted the seller because we got together on the deal here on VV.  I shouldn't have trusted him as it turns out..  Among other things, he claimed the motor spun freely.  Since I was going to do a complete rebuild anyway, that was fine.  The reality is that I have never seen an engine more solidly seized.
 
I tried the breaker bar that people mentioned.  I tried the breaker bar in combination with a strap wrench on the damper and nothing worked.  I didn't use compressed air.
 
I put the motor on an engine stand and removed the heads, oil pan and top.  This gave me access to both the top and bottom of the cylinders.  I turned the motor sideways on the stand and squirted different solvents at different times into the tops and bottoms of each cylinder.  Those cylinders facing up got the solvents to the top of the piston and those facing down got the solvents to the bottom of the piston.  I let it soak for a day and then turned the motor the other way to get to the tops and bottoms of the other set of pistons.  This went on for a couple of weeks without success.
 
I decided to dismantle the engine.  I tried to remove the rod caps so I could remove each piston and cylinder as an assembly.  Because the engine had seized in exactly the wrong position, I could only get to some of the nuts for the rod caps.  I did remove two piston/cylinder assemblies this way but the remaining four cylinders were still seized.  Because I couldn't get to the remaining nuts with a socket or wrench, I had to resort to using an abrasive wheel.  By the way, once the two piston/cylinder assemblies were removed, it gave me access to a couple more nuts through the open holes but even one nut in place on a rod cap is enough to prevent removal.
 
Once I had all six piston/cylinder assemblies out, I had to separate one from the other.  I used my hydraulic press.  With a couple assemblies, it was difficult setting them up on the press because the wrist pins had seized too and the rods had frozen sideways.  Keep in mind that frozen piston rings are only part of the problem.  Wrist pins, rod bearings and main journal bearings can get stuck too.  I had to push the press to its limit and when the rings released, it sounded like a small caliber pistol shot.  Of course, the pistons and rods were trash but I sent the cylinders off to a vendor to be resurrected.  
 
I could bitch about other things the guy who sold me the motor did but those are stories that are not pertinent to seized motors.
 
With all that, I ended up with the proper crankcase for my car, rebored cylinders, a rebuildable turbo and carb, the proper distributor, etc.  Because of the way the seller shipped it, there was damage to other components but nothing that couldn't be fixed or replaced.  All-in-all, even if the seller is a member of VV, I will never buy a motor, car or other significant part remotely unless the individual is truly trusted or someone I trust inspects the unit in question.
 
I hope this helps.
 
Good luck Ignacio
 
Doc
'60 Corvette; '61 Rampside; '62 Rampside, '64 Spyder coupe, '65 Greenbrier; '66 Canadian Corsa coupe; '67 Nova SS; '68 Camaro ragtop; '70 3/4 ton Chevy C20 pickup plus a couple other non-Chevy vehicles ... forgive me
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In a message dated 6/20/2018 5:55:47 AM Pacific Standard Time, virtualvairs-request at corvair.org writes:

 

Message: 1
Date: Tue, 19 Jun 2018 22:28:11 -0500
From: Ignacio Valdes <ivaldes at hal-pc.org>
To: Virtual Vairs <virtualvairs at corvair.org>
Subject: <VV> Freeing a stuck motor.
Message-ID:
 <CANPWqJFfZWdREwCz3pegPsrVg=Ywip30zw_v7EJKRN40QmsejQ at mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"

Hi, I am giving the old college try for a 1964 stuck motor that was given
to me for 'free'. It is out of the car on the floor. A 3/4 inch wrench on
the harmonic balancer bolt head does not make it budge. The starter is bad.
I pulled the plugs and poured a gallon of ATF into the spark plug holes
today. How long should I wait and are there any other ways of trying to get
it moving other than the bolt head on the harmonic balancer? -- IV