<VV> Problems with a 140 tear down
Ken Pepke
kenpepke at juno.com
Fri Sep 2 11:32:59 EDT 2011
My personal experience tells me that seized engines are [perhaps] always the rings to the cylinder walls. That makes a Corvair engine the easiest of all to 'unstick.' First, resist the urge to use any kind of penetrants. Remove the heads. Next, heat the cylinder barrels, one at a time, to red hot all around in the area of the rings. Hit the sides of the cylinder barrel with a heavy rubber mallet directing the force in such a manner as to drive the cylinder barrel out of the block and off the piston. It is a good idea to place something under the engine [wooden box?] to catch the cylinder barrel. It is not a good idea to try to catch it by hand.
Once off, all parts once cooled, less the rings, can be reused.
Ken P
Wyandotte, MI
Worry looks around; Sorry looks back, Faith looks up.
******************************************
> From: RoboMan91324 at aol.com
> Date: September 1, 2011 10:35:04 PM EDT
> To: virtualvairs at corvair.org, bgilbert at gilberts-bc.ca
> Subject: <VV> Problems with a 140 tear down
>
> Bob,
>
> A few years ago, I bought a complete 180 engine from a VV'er in the
> Chicago area. He told me that the engine turned freely. Nothing could have been
> further from the truth. In my decades of experience, I have never seen an
> engine more solidly seized. I won't take the time to explain all of the
> things that were wrong with this engine contrary to the seller's description
> but will keep my story to just the dismantling of the engine. I will tell
> you what I tried initially just in case it might work for you and will
> tell you what finally worked.
>
> First, I tried to turn the crankshaft with everything intact including the
> heads. Nothing moved.
>
> Second, I took everything off of the engine down to what would be
> described as the "short block." What remained were the cases, crank and cam
> shafts, pistons, cylinders, con rods and caps.
>
> Third, I mounted the engine on an engine stand to make everything more
> convenient. I turned the engine sideways so the cylinders were facing up and
> down. I used PB Blaster and other products that had been recommended here
> on VV. I squirted the stuff into the combustion chambers which faced up
> as well as into the bottom of the pistons on the other side of the engine
> that were facing down. My thought was to attack top and bottom rings as well
> as the wrist pins at the same time. Also, with the pistons facing
> directly up and down, this assured that the Blaster would contact the rings all
> the way around the cylinder. I have always felt that if the piston/cylinder
> was in the normal horizontal position, contact of the Blaster with the
> rings would only be partial. You can't trust capillary action to draw the
> solvent to all parts of the rings.
>
> Every day I would apply more Blaster and every few days I would turn the
> engine 180 degrees on the stand so the trio of cylinders facing up and down
> were reversed and I would apply more Blaster or other product as described
> above. Each time, I would give the tops of the pistons a good smack or two
> or three with a hammer. I would use a piece of steel as an extension for
> those pistons which were too far down in the cylinders to reach with the
> hammer alone. Obviously, with pistons so firmly seized, I assumed the
> pistons were worthless even if I wanted to reuse old pistons so I didn't care
> about dents in the pistons. I tried this for weeks without success.
>
> Fourth, I tried to unbolt the connecting rod caps so I could try to pull
> the connecting rod, piston and cylinder from the engine as assemblies.
> Because I couldn't turn the crank, I couldn't get to all of the cap nuts with
> traditional tools. I spent an obscene amount of time trying to do this and
> even ground down some sockets to try to get them to fit awkward positions.
> This helped and I eventually got all the nuts off. I even tried a
> nutcracker. I removed four of the rod/piston/cylinder assemblies by tapping the
> cylinders with a dead blow hammer while pulling away from the crankcase.
> With a couple of these assemblies removed, I had easier access to a few more
> cap nuts through the now empty cylinder holes in the cases. I was stuck
> on the last two assemblies because the crankshaft's rod journals were seized
> in exactly the worst position. The journal side of the rod was too close
> to the crankcase to pull the rod/piston/cylinder assemblies out. The rod
> cap bolts couldn't be removed because they were also too close to the
> crankcase to slide out of their holes. I couldn't pull the case halves apart
> because the rods were at an angle that caused interference with the crank
> journals. Because I couldn't remove the cap bolts, I couldn't tap the con rods
> to break the wrist pin seizure. I did not want to damage the crank
> journals with the con rod bolts or edge of the con rod. Be careful with the
> crank if you think all it needs is a polish. To get the last assemblies out, I
> had to use a pneumatic cut-off tool to cut through the remaining con rod
> bolts. With those out of the way, I was able to remove the last of the
> assemblies.
>
> Fifth, I pressed the pistons out of the cylinders with a hydraulic press.
> I felt I was beginning to over stress the press but the pistons finally
> let go with a "crack" that sounded like a small caliber gun. The first one
> scared the poop out of me so be prepared. Fortunately, the cylinders were
> salvageable. I sent them to one of our valued vendors for exchange.
>
> Lessons learned:
>
> First, I was not pressed for time but even so, I wasted plenty of it with
> the benign methods described. If those efforts don't work in a reasonable
> time, go to more drastic methods sooner than I did. With 20:20 hindsight,
> perhaps I should have even considered cutting the con rods themselves if
> there was no risk to the cases or crankshaft. Think about the value of the
> time wasted vs. the value of new rods.
>
> Second, be careful of who you deal with even here on VV. There were
> several chapters in my horror story with the seller other than the terribly
> seized engine he claimed to be "free turning." The person I dealt with was in
> the Chicago area and I am on the west coast. We never met face-to-face.
> This man was on VV for a few months before our transaction started and
> remained here for a few months after I finally received the engine. To my
> knowledge, he left VV unless he remains a lurker. Don't get me wrong, I would
> happily deal with most of the people on VV even sight-unseen but I am now
> leery of "short timers" that I cannot meet face-to-face first. At least that
> is the case with high dollar items.
>
> Good luck Bob
>
> Doc
>
> 1960 Corvette, 1961 Rampside, 1962 Rampside, 1964 Spyder coupe, 1965
> Greenbrier, 1966 Canadian Corsa turbo coupe, 1967 Nova SS, 1968 Camaro ragtop
>
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